 |
InspectAPedia® |
InspectAPedia
|
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair | Ask a Question or Search InspectAPedia |
|
Here we explain hot water boiler (hydronic heat) pressure reducing valves and types of manual and automatic water feeder valves used on hot water heating boilers, including when and how to add makeup water to a boiler. A chart illustrates the adjustment to heating boiler operating pressure as a function of building height or the number of floors in a building being heated. We include photographs of common pressure reducer valves and water feeders used on hot water heating boilers to aid in product identification, links to installation manuals, safety warnings, installation and pressure reducer / water feeder safety and maintenance tips. Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman. Hydronic (hot water) Heating Boiler Water Feed Valves
The photo above shows a modern automatic pressure-reducing water feeder valve on a hydronic (hot water) heating boiler - one of the safety controls which we discuss in this article. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. Manual water feeder valves on hot water boilersHydronic (hot water boilers) in proper condition do not normally consume any water. Once the boiler and the baseboard, radiator, or convector piping are connected and filled with water, that same water remains in the system indefinitely. The water in the boiler is heated and circulated through the occupied space to provide heat to the building occupants. Water may be lost from a hot water heating system, however, due to a small leak that may be un-noticed, or water may be removed from the system during servicing. Some older heating systems may not have an automatic water feeder and may only provide a manually operated valve to add water to the boiler. To maintain the water level in these heating systems, water can be added from the building water supply piping manually by simply opening a make-up valve. A manual valve will simply be a shutoff valve that can be opened by hand to force water into the heating boiler. Automatic water feeder valves on hot water boilers
On these older systems the "automatic water feeder" is often a bell-shaped device which opens and sends makeup water into the heating boiler and its piping whenever the heating system's internal water pressure falls below a normal level (perhaps 12 psi when the boiler is cold). In our photo at left the gold colored bell-shaped device pointed to by the red arrow is an automatic pressure-reducing & water feed valve for a hot water boiler. An arrow cast into the valve base shows the direction of water flow (from building supply at right into the boiler at left in this photo). The screw and lock nut on top of this valve permit adjustment of the automatic water feeder valve pressure (it's normally set to 12 psi). The horizontal lever is a bypass that will send water through the valve on to the boiler at full building pressure (it's normally left "off" in the position shown here). The separate heating system backflow preventer / check valve indicated by our green arrow is discussed in more detail at BACKFLOW PREVENTER VALVE, HEATING SYS. Automatic Heating System Automatic Water Feeder Includes Built-In Backflow PreventerThe device to the right of the automatic pressure reducer (water feed valve) in our photo above is a back-flow preventer that is required in some municipalities. The back-flow preventer makes sure that water from inside the heating boiler cannot flow backwards into the building (and community) water supply. This prevents back-contamination of potable water piping from the boiler should the building water pressure fail. See CHECK VALVES, HEATING SYSTEM for more information about backflow preventers and other heating system check valves.
So is the B&G Pressure Reducer an Automatic Water Feed Valve or Not?Well yes, and no. The valve can automatically feed water into a hot water heating boiler whose pressure falls below the set-pressure (12 psi at factory setting) if the water shutoff valve for the boiler has been left "on".
But the manufacturer warns that the purpose of the pressure-reducing (and automagic water feeding) valve is to fill heating boilers after installation or servicing. The company says "It is not a safety device and is not intended to be used as as a water feed valve to control boiler water at a safe operating level". OPINION: this is interesting since for closed-system hydronic heating boilers (not steam boilers) that's how lots of service techs and inspectors view this device. In the company's service manual you'll see on the installation piping sketch (edited) for the pressure reducing valve (green, to the right of the blue shutoff valve at the left side of the sketch below) that they expect the installer to include a water shutoff valve (blue at the left end of the sketch below) before this pressure reducer.
| ||||||||||
If your heating system uses a steam boiler, see 
 
|
Our photo at above left shows an Armstrong™ pressure reducing valve. The schematic at above right, courtesy of Carson Dunlop, explains how this pressure reducing valve works.
Our photo (left) shows another model of pressure reducer valve on the water supply line to an Energy Kinetics oil fired heating boiler. The lever on the top of this valve combines a full-open bypass (when the lever is vertical) and a set-pressure adjusting locknut (below the round lever body). |
Safety note: If the pressure reducing valve is combined with a pressure relief valve, for safety these parts must be installed in the correct position.
As Carson Dunlop Associates shows in the sketch above, and as you'll also see in the B&G installation piping sketch, the pressure relief valve should always be installed closest to the heating boiler so that it can respond to an overpressure in the heating system.
What is the proper water pressure setting for a pressure-reducing valve or water feeder valve on a Hot Water Heating System?
What is the normal operating pressure of a hot water heating system boiler?
Hydronic heating systems (hot water) typically operate at about 12 psi cold and see a pressure increase to somewhere just under 30 psi when the system is at maximum temperature.
If you set the water feeder pressure too high it's likely that when the boiler heats-up to operating temperature, the water pressure will exceed the safety limit (30 psi) and the boiler relief valve will open to discharge excess pressure and water.
Because a hydronic heating system's circulator pump has little "lift" capacity (it just pushes the water around the loop of boiler and heating piping and radiators), the heating system depends on its internal water pressure to lift hot water to radiators (baseboards, or convectors) on upper floors in the building.
A higher building may therefore need higher heating system water pressure in order to be able to circulate heat adequately to upper floors. The sketch, courtesy of Carson Dunlop, explains that a three-story building will need heating system pressure set up to at least 15 psi. when the heating boiler is cold.
But in most cases you should leave the water feeder at the psi set by the installer (typical factory setting is 12 psi) unless the building has unusual conditions (such as more than two stories) that require a higher in-boiler starting water pressure.
Automatic Water Feeders Built-Into Expansion Tanks
An automatic water feeder valve is included as part of some heating system expansion tanks on hydronic heating boilers - in a single unit such as those provided by Amtrol™, Extrol™, Fill-Trol™, or
similar expansion tanks.
The water feeder is the brass assembly found attached to the expansion tank where piping from the boiler enters the tank on these units.
In our photo at left you can see the brass valve on top of the Fill-Trol™ expansion tank and underneath the cast iron air purge valve (red arrow).
The vertical copper pipe is feeding water from the building supply, at building water pressure into the brass valve and through it, upwards into the heating system distribution piping through the silver painted cast iron air purge valve.
This automatic water fill valve is not adjustable by the consumer and is factory-set to add water to the heating boiler whenever the system pressure falls below 12 psi.
The tank below the red arrow is, of course, an expansion tank. We discuss expansion tanks and their troubleshooting or maintenance at EXPANSION TANKS.
Steam Boiler Water Feeder Valves, Automatic & Manual
Also see our detailed article on automatic water feeders for steam heating boilers, at WATER FEEDER Valves, Steam.
Keeping the proper amount of water in a steam boiler is a critical function for both safety and to avoid damaging the boiler itself. So on a steam boiler we consider the automatic water feeder to serve as a safety device too. Water feed valves on steam heat systems operate under very different requirements than those on hot water (hydronic) heating systems.
Automatic water feed valves on steam boilers (such as the McDonnell & Miller automatic water feeder shown at left) perform functions similar to the valve described earlier for hot water boilers.
Residential steam heating systems are mostly "low pressure" systems operating at less than 2 psi. In fact if you see the pressure set higher on a residential system it is often an indicator that the occupants/technician have been having trouble getting the steam heat to locations where it's needed. All steam heat systems all consume some water which escapes from radiator air vents during the time that the steam (heat) is first rising in the building. So unlike a hydronic water feeder, the steam boiler water feeder is going to be much busier, regularly adding makeup water to the steam boiler, but operating at low water pressures.
Steam heating systems without an automatic water feeder are less safe and risk serious boiler damage should boiler water be lost and should there be no low water cutoff installed on the system. That's why all modern steam heating boilers can be expected to include at least a low water cutoff valve. Low water cutoff valves are discussed in detail at Low Water Cutoff Valves, Boilers.
How to Install or Service or Repair an Automatic Pressure Reducing Valve / "Water Feeder"
The following advice is adapted from Bell & Gossett's Instruction Manual V55999 Rev. M. Reducing Valves Installation & Service Instructions - a booklet that the installer is supposed to have been left for home owner use.[4]
Select the Proper Pressure Reducing Valve
There are multiple B&G pressure reducing valve models, not to mention competing valves made by other manufacturers. Valves vary by their pipe diameter (1/2" or 3/4"), connection type (union or NPT/Sweat), and by factory setting and adjustable pressure range. The latter two key parameters are pretty simple as there are 2 ranges:
- Factory set water feed pressure: 12 psi, with adjustable range of 10 psi to 25 psi (typical use on residential heating boilers)
- Factory set water feed pressure: 45 psi, with adjustable range 25 psi to 60 psi (you won't use this on a typical residential heating boiler)
Pressure Reducing Valve Specifications
- The maximum flow rate for these pressure reducer valves is 5 1/2 to 6 gpm presuming input pressure of 125 PSI - which is higher input than found at most homes.
- The maximum operating temperature for these pressure reducers is 225 degF.
- The maximum working pressure for these pressure reducer valves is 125 psig.
Pressure Reducer Valve Installation
Install the Pressure Reducer Valve Right side up:
Watch out: while some pressure reducer / water feeder valves work in any position, some models such as B&G's "Fast-Fill" pressure reducers must be installed in an upright position. What's "upright"?
Point in the right direction: The cast-arrow indicating direction of water flow must be in a horizontal position (and of course pointing towards the heating appliance).
Feed with cold water: We suspect that on occasion a plumber may supply the valve with hot water, thinking s/he is reducing the risk of damage that can happen by feeding cold water into a hot boiler. While the installation instructions don't explicitly say so, the illustration provided by the manufacturer shows that the pressure reducer / water feeder valve that is going to supply water to a heating boiler is itself fed by the cold water supply piping in the building. And the manufacturer's instructions consistently refer to supplying cold water to the equipment, for example:
Open the cold water fill valve to allow the system to fill until the preset pressure of the valve has been obtained.
Install a water shutoff valve on the inlet (water supply side) of the pressure reducing valve.
Install a bypass valve and piping arrangement for fast filling of an empty heating boiler if the pressure reducer valve model you're installing is not itself a "Fast Fill" model.
Watch out: if you install a bypass valve to allow fast filling of the heating boiler, make sure that this bypass is closed during normal boiler operation. Otherwise the boiler will be over-pressurized, the relief valve may spill, equipment or the building may be damaged, the equipment may be unsafe.
Install other safety controls: B&G recommends for safe boiler operation that a low water cutoff valve (LWCO), adequate burner safety controls (cad cell sensor etc), and a properly-installed float-operated water feed valve should all be installed. We are seeing more LWCO's installed on both hydronic and steam boilers, required by code in some jurisdictions. And it's rare to see a modern steam boiler that does not have the recommended automatic float operated water feeder. Without these controls, and without appropriate air controls (air purger and thermal expansion compensation), B&G warns that the boiler may not work properly nor safely.
Don't over-do the pipe joint compound: the manufacturer warns to use pipe joint compound sparingly (not "the bigger the blob the better the job" as Dan B. Martin used to say). The concern is that excessive pipe dope oozes into working control parts and can prevent safe, proper operation of the equipment.
Warning when using teflon tape on threaded pipe fittings: the same manufacturer warns that use of Teflon impregnated pipe compound and Teflon tape on pipe threads provides so much lubrication that it's easy to over tighten and damage the parts - risking unsafe or damaged equipment. Indeed we found that when tightening a part such that we are approaching the part's desired final position, the lubricant effect of teflon can cause you to turn the part too far - so you're tempted to turn it for another complete rotation to get it where you want - followed by breaking the part.
Disassemble some parts when "sweat fitting" (soldering) them in place: when installing a reducing valve using soldering, to avoid damaging the valve by overheating it, first sweat the union connection fitting onto the system piping, then connect it to the valve.
Water feed pressure adjustment - at initial installation
When the pressure reducing valve installation is complete and you are ready to fill the heating boiler, open the cold water fill valve to allow the system to fill until the preset pressure of the valve has been obtained. (Residential pressure typically starts at 12 psi cold).
If you are using a Fast Fill model pressure reducing valve, instead of filling the system through the bypass valve and piping you lift the fast fill lever to the vertical position, overriding the pressure regulating features of the valve and allowing water to enter the heating equipment and piping at building water supply pressure. So be sure to stop filling when pressure in the heating system is at the proper cold-water temperature pressure.
Watch out: after this initial boiler fill-up, close the fast fill lever - don't leave it up - open or the system will be unsafe and possibly damaged.
For pressure reducing valve feed pressure adjustment to meet varying building conditions such as tall structures that need higher starting pressure, see the detailed explanation found above in this article.
Pressure Reducing Valve Troubleshooting, Inspection, Service & Repair Procedures
Inspect & Check the Pressure Reducer for Proper Operation, Clean the Strainer if Needed
B&G offers some excellent tips on how to check the pressure reducer for proper operation, and how to fix some common problems.
- Check for corrosion, damage, or leaks at the pressure reducing valve.
Watch out: if you find corrosion, damage, or leaks at the pressure reducer valve, these should be taken as a very serious warning that the valve is about to cause serious damage, leakage, rupture, and unsafe conditions. This valve should be inspected periodically, in our OPINION [DF] no less than at annual heating system service time. Unsafe heating equipment or controls can cause injury, death, or property damage. - Check to see if the valve is feeding water into the boiler: feel the temperature of the pressure reducer valve body: put your hand on the bell-shaped body of the pressure reducer or on the piping before and after the valve. If the metal is cold to the touch in those areas, then the valve is "passing water" into the heating boiler. This should not be happening if at the same time the heating boiler is already up to its operating temperature. Possible causes:
- improper reducing valve pressure setting
- a leak "downstream" from the pressure reducing valve, in the heating system piping or boiler or its controls
- a faulty pressure reducing valve that is not closing when it should
- If the relief valve on the heating boiler periodically leaks or discharges water, on a hydronic heating system (hot water boiler) the expansion tank may be waterlogged - losing the "air cushion" intended to accommodate thermal expansion. Details offering more thorough diagnostics are at RELIEF VALVES - TP Valves on Boilers and at RELIEF VALVES - STEAM TP VALVES and of course also at EXPANSION TANKS. But one tip for waterlogged expansion tanks that use an internal bladder is one we hand neglected to mention: pump a bit of air into the expansion tank, then put a dab of water (we recommend spit) on the opening of the air valve found on the bladder-type expansion tank. If the spit bubbles the valve is leaking.
- Check for a clogged strainer in the Pressure Reducer/Feeder Valve: if the pressure reducer will not feed enough water into the boiler to reach the desired cold-pressure setting, before messing with re-adjusting the valve's feed pressure nut and screw, consider that the internal strainer in the valve may have become clogged.
- Turn off the cold water supply valve at the inlet side of the pressure reducing valve
- Turn off the heating boiler - set the electrical service switch to OFF to shut down the entire system.
- Remove all pressure and temperature from the heating system to allow safe work on the pressure reducing valve
Watch out: water in the heating boiler may be at dangerous high pressure or high temperature. Before proceeding to work on the pressure reducer valve you must either reduce the heating system internal water pressure to zero, OR you must isolate the pressure reducing valve from the rest of the the heating system. Leave the system drain valve open and allow the heating system to cool to a safe temperature - below 100 degF. Otherwise you risk serious injury or death or property damage. - Loosen and remove the strainer nut located on the bottom of the pressure reducing valve
- Remove and clean or replace the strainer found in that opening
- Reinstall the strainer and nut with its O-ring (don't lose or damage the O-ring or the valve will leak) and tighten the nut to at least 10 inch-pounds of torque, and not more than 100 inch-pounds of torque.
Watch out: don't use Teflon tape when installing the pressure reducer strainer nut and o-ring or the risk is that you will over-tighten and damage the equipment making it and the system unsafe, risking injury or damage. - Close the heating boiler drain and re-fill the heating system with cold water.
- Vent any excess air from the heating system - as you may have introduced air during the drain and refill procedure. Remember to close the bypass valve or fill valve when the heating system has been filled to its cold starting pressure.
- Check the system for water leaks, especially where you have been working and disturbing parts
- Turn the boiler electrical service switch back on, make sure the room thermostat is calling for heat, allow the heating system to resume normal operation.
- Check a last time for leaks.
Using the Pressure Reducer Valve Repair Parts Kit
B&G provides a repair parts kit for this valve.
- To use the pressure reducer valve repair kit you will need to shut down the heating system, drain it, cool it, as we described just above at the strainer cleanout procedure. Then
- Remove the valve body cover using a #25 Torx screwdriver that fits the screws around the valve body; B&G points out that you can use 1 /8" Allen wrench instead of a #25 Torx driver in an emergency but we can confirm that you will probably strip and damage the screws, just as a Harley Dealer's mechanic did to my Road King (another argument for doing your own work).
- Remove the valve spring cap and spring you'll find inside
- Remove the hex nut (this is the lock nut that holds the screw stem in place) by holding the stem assembly stationary while turning the nut counterclockwise. B&G warn that the stem may drop when you remove the hex nut.
- Lift off the spring plate, diaphragm, and valve plate - I'd inspect all of these parts and the others listed below for damage
- Pull the rubber check valve from the valve body and replace this part
- Insert the new valve stem assembly (that came in your repair kit) into the valve body through the strainer opening in the housing, and hold it in place. [A helper may be handy here]
- Place the new valve plate, knob side down, on the stem assembly
- Set the new diaphragm on top of the valve stem, aligning the holes in the rubbery diaphragm material with the screw holes in the valve body - you want the reassembly screws to line up with these holes - otherwise the diaphragm may end up cut or twisted and you'll have ruined the job
- Place the spring plate over the diaphragm on top of the stem assembly
- Thread the hex nut onto the valve stem assembly. A dab of Loctite (thread fastener) must be added to the hex nut before threading it onto the stem.
Watch out: don't use more than a tiny dab of Loctite or you will seize the valve, making it inoperative and the system potentially dangerous - Place the spring, cap and body on top of the valve
- Align the valve body cover holes with those in the body (you got that diaphragm straight, right?) and fasten those stripped (or replaced) Torx T-25 screws into the body
- Reinstall the strainer nut (the strainer is in place, too, right?) with its O-ring into the reducing valve body bottom and tighten it to at least 10 inch pounds and not more than 100 inch pounds.
Watch out: see our warning above about watching for a damaged O-ring (replace it) and about not using Teflon tape on this part, at risk of over tightening - Close the boiler drain and refill and vent air from the heating system with cold water as we described above. Remember to close the cold water bypass valve or fill valve.
- Check for leaks
- Turn the heating system on, st the thermostat to call for heat if necessary, let the system reheat,
- Check again for leaks
- Check the system operating pressures cold, and hot
Frequently Asked Questions (FAQs) about heating boiler pressure reducing valves, water feed valves, check valves: operation and repair
Question:
I have a gravity feed system with water radiators in my home. When I leave the incoming water on the pressure in my system goes sky high the expansion tank discharges the water. When my system is full of water and I turn off the incoming water by the water feeder my system loses pressure and I have to add water again thru the water feeder. Is my water feeder the issue?? When the system loses pressure where is that water going?? The expansion tank is above my furnace in my basement. Any help would be appreciated!! Thanks, Fred
In regards to my gravity feed system "pressure" problem question -- Municipal water, system has been working fine for last 15 yrs. When system full of water home heats fine but when furnace off pressure drops. Thanks, Fred
Reply:
Fred,
Particularly with a gravity circulating system, that is you rely on hot water rising through the heating pipes by convection rather than by using a circulator pump, if there is not enough pressure in the heating system hot water may rise too slowly or even not at all to upper floors in the building.
Check the water pressure in your heating boiler (furnaces are hot air systems, water based heating systems are boilers) when the system is cold - for a typical 2 story home you'll want to see 12 psi cold pressure in the boiler.
If your boiler pressure is low and/or if you've had a leak and lost boiler water leading to low pressure AND if your water feeder valve is not working properly (or is not properly set) then you may have low boiler pressure.
Also take a look at "What is the proper water pressure setting for a pressure-reducing valve or water feeder valve on a Hot Water Heating System?" in the article above.
Question: My house is too hot and the boiler circulator keeps going even if I turn down the thermostat
The circulator pump on my Weil Mclain boiler doesn't respond to the thermostat. I closed the manual flow valve to prevent the baseboards from "heating" during the summer. I recently had to open the valve to provide heat to the house now that it has gotten colder but when the house heated up too hot the flow valve would not close and the baseboards continued to receive hot water. How can i "fix" the valve to shut off the water supply to the baseboards? Will i need to purge the water from the zone to replace the valve? - House too hot 12/21/11
Reply:
House too hot:
You're asking a question under an article on automatic water feeders -- valves that maker sure the water in a heating boiler is kept at proper level. This won't help you with a heat control issue.
Under BOILERS HEATING (links at Related Topics ) you'll see BOILER CONTROLS & SWITCHES - an article that lists various boiler controls. Your control problem could be in any of several places
- the wall room thermostat - THERMOSTATS, HEATING / COOLING
- the circulator control and relay switch (good guess) - see Circulator Pumps & Relays
- and the flow control valve - which should act as a check valve to prevent hot water from circulating up out of the boiler when you are not calling for heat - see CHECK VALVES, HEATING SYSTEM.
Fixing the problem by opening and closing the flow-control valve is a stopgap that as you have seen, is not a great solution.
Your system may have two faults:
1. the hot water should not be circulating out of the boiler in summer when you never call for heat - this is a flo control valve problem, presuming that there is some reason that the boiler is hot in the first place (like keeping it hot for making domestic hot water)
2. the circulator not responding to the thermostat - sounds like a circulator relay control problem, presuming that it used to work and that no one changed the wiring.
To replace a flow control valve or some circulator pump assemblies that are plumbed directly in line in the hot water heating system, unless there are isolating shutoff valves before and after the device, you'll need to cool down the system, drain the affected piping, replace the part, and indeed, purge air from the lines to restore heat.
Keep us posted - what you learn will help other readers.
Question: Top floor radiator is not getting water - should I up the system pressure?
I have a home with 3 levels above the basement, and radiators on every floor. The radiator at the very top floor does not seem to even contain water, and bleeding does not help. The radiators on the 2nd floor, just below the attic used to heat up fine, but now they do not seem to have water either. Obviously, there is a pressure issue here, but I had the water feeder valve for my hydronic system replaced just 4 years ago. The radiators in the basement and on the first floor work just fine. Can I turn the pressure screw on the water feeder to increase the pressure while the system has been operating for the past 2 months and the boiler is not cool? - Joey Butters 12/31/11
Reply:
Joey I would NOT start by changing system pressure since there is a good chance that your top floor radiator is simply air bound. Hop over to our radiator troubleshooting articles at RADIATORS and you'll see how to check for and fix an air-bound heating radiator by simply opening an air bleeder.
Question:
i have a three zone ( individual circulator pumps) hydronic system that i recently changed the expansion tank and auto bleeders on and now it wont keep pressure for more than an an hour or so i have searched the system for leaks and cant see any. i have to keep adding water to get pressure back. what else could be wrong and can i leave the make up water valve (not the pressure reducing valve) but the one that feeds it open? is this dangerous?? it is a two story house - Martin Griffin 1/15/12
Reply:
x
Question: The relief valve at my boiler keeps leaking, even after we replaced it
My boiler has been leaking at the pressure relief valve for 1 week, with the pressure at 30-35 when hot. I drained the steel expansion tank fully, and then re-started the system. The pressure initially was back down around 20, but within 1 day was back up in the 30s and leaking at the PRV. I had a technician come and install a new pressure reducing valve. We all thought that would fix everything. We drained the expansion tank again before re-starting the system. After we re-started the system, the pressure continued to rise. one day later we're back at 33 PSI and draining from the PRV. I tried draining more water from the expansion tank and closing of the water valve from the city. The pressure in the system went down to 20. After running the heat, it's now hot and at 25 psi. Could I have just gotten a defective new pressure-reducing valve? Any thoughts? Help would be appreciated. - Josh 2/7/12
Reply:
Great question Josh. There are actually several things that can cause the relief valve on a boiler to leak, among them is an automatic water feeder/pressure reducer that is not working properly, but there are quite a few other causes too. The fact that you drained your expansion tank and then found that you could drain it again makes me suspect that as the best starting place. If it's an older bladderless type expansion tank (some call these compression tanks) it may be that it wasn't adequately drained. If the expansion tank is a newer type that has an internal bladder the bladder may be damaged or the air valve may be leaking out the air charge. Details are at EXPANSION TANKS.
At RELIEF VALVE LEAKS we provide a catalog of all causes of leaks at all types of pressure or pressure / temperature relief valves.
Also see RELIEF VALVES - TP Valves on Boilers if your boiler is a steam boiler, or if yours is a hydronic (hot water) system see RELIEF VALVES - STEAM TP VALVES
Question: the water level in my steam boiler keeps rising
my sight glass on manual feed boiler rising without adding water I have steam heat system with
an indirect water heater. - Anon 2/23/12
Reply:
Anonymous:
Your water feeder valve may need repair or replacement. Review the diagnostic text in the article above. This is particularly likely if the boiler level is actually increasing. Don't confuse increased boiler water level with surging when the steam boiler is heating up.
And don't forget to double check that someone else has not manually added water to the boiler.
Question: What should we report if finding a water feed valve tied off as shown in this photo?
Tom Sherman - President, Absolute Home Inspection, Inc., 315-673-1755 provided this photo of a tied-off pressure-reducer water-feed valve and asked what we'd say about it, for an ASHI home inspector newsletter. Home inspectors are expected to be competent to recognize conditions at a home that are improper, unsafe, not functional, etc. provided that the problem or component is readily accessible, visible, and under some other conditions. In this photo we have a pressure-reducing water feed vavle typically used on a hot water or hydronic heating system. The valve valve, this one is a B&G model, has the job of feeding makeup water to the heating boiler should the water pressure in the heating system fall below the set-pressure on the valve - typically 12 psi for most one or two story residential buildings, though the set pressure may need to be higher in taller structures. The water feed valve's override lever in the photo has been secured to the water pipe by a black plastic tie. The override lever is used to put the water feed valve into "bypass mode" by lifting the lever to a 90-degree position above the water piping and valve body - meaning that the valve is manually forced "open" to allow water to enter the heating boiler at whatever pressure is on the inlet side of the valve. (The heating boiler, not shown here, is always on the outlet side of the valve, and on most of these controls an arrow cast into the valve body indicates the intended direction of water flow. In our photo we've drawn a blue arrow showing the direction of water flow for this valve. Click the image to see an enlarged version. If the valve were in manual OPEN mode, the lever would be at right angles to the piping and valve body - its handle would be over the adjustment screw shown in the center of the valve top. So this valve is in the CLOSED position. Why would someone put a plastic tie on the automatic water feed valve override lever to hold it in the CLOSED position?Perhaps the heating service technician was annoyed by an owner's emergency service call complaining that the pressure / temperature relief valve was spilling and perhaps the tech found that the owner had been messing with the valve and over-pressurizing the boiler. If you set the boiler water pressure too high when cold then when the boiler heats up the pressure will exceed the (roughlyy 30 psi) pressure at which the relief valve will open. But a more likely reason this valve was tied OFF or CLOSED was that it was leaking, feeding excess water pressure to the boiler on its own. One of the failure modes of these valves is that the valve begins to feed water when it should not. That can happen due to dirt and debris in the valve or for other reasons. Someone was trying to force the valve to behave itself. Functional & Safety Worries with a Bad Behaving Water Feed Valve Watch out: this is not only an improper heating system operating setup, it is potentially (though subtly) quite dangerous:
Watch out: The manufacturers of this type of automagic water feed valve recommend that additional manual control valves be included in the piping system, so in some installations you might also find that the automatic water feeder is not really so automatic. At InspectApedia's WATER FEEDER Valves, Hydronic where we discuss this valve in detail. In that article we report this interersting fact:
Which is pretty interesting since so many people in the trades as well as among inspectors consider it a safety device. |
x
Ask a Question or Search InspectApedia
Questions & answers or comments about heating boiler pressure reducing valves, water feed valves, check valves: operation and repair
Ask a Question or Enter Search Terms in the InspectApedia search box just below.
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.
- [1] Thanks to Mark Cramer, Tampa Florida, for assistance in technical review of the "Critical Defects" section and for the photograph of the deteriorating gray Owens Corning flex duct in a hot attic. Mr. Cramer is a Florida home inspector and home inspection educator.
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. (416) 964-9415 1-800-268-7070 info@carsondunlop.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides:
- Commercial Building Inspection Courses - protocol ASTM Standard E 2018-08 for Property Condition Assessments
- Home Inspection Education Courses including home study & live classes at eleven colleges & universities.
- Home Inspection Education Home Study Courses - ASHI@Home Training 10-course program.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author. - The Home Reference Book, a reference & inspection report product for building owners & inspectors.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author. - The Home Reference eBook, an electronic version for PCs, the iPad, iPhone, & Android smart phones.
Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter inspectaehrb in the order payment page "Promo/Redemption" space. - The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors.
Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space. - The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones.
- Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
- [3] B&G Flo-Control Valves - installation, operation, and service instructions manual - original source Bell & Gossett, 8200 N. Austin Ave., Morton Grove IL 60053, USA - Tel 847 966-3700 Fax 847 965-8379 . www.bellgossett.com/BG-Literature-Detail.asp?LiteratureID=607
- [4] B&G / ITT Reducing Valves, Instruction Manual V55999: Reducing Valves Installation, Operation, & Service Instructions, Bell & Gossett Air Separators and other heating system components, Bell & Gossett, 8200 N. Austin Ave., Morton Grove IL 60053, USA - Tel 847 966-3700 Fax 847 965-8379. Original source www.bellgossett.com/literature/files/610.pdf
- Fuel Oil & Oil Heating Magazine, 3621 Hill Rd., Parsippany, NJ 07054, 973-331-9545
- Domestic and Commercial Oil Burners, Charles H. Burkhardt, McGraw Hill Book Company, New York 3rd Ed 1969.
- National Fuel Gas Code (Z223.1) $16.00 and National Fuel Gas Code Handbook (Z223.2) $47.00 American Gas Association (A.G.A.), 1515 Wilson Boulevard, Arlington, VA 22209 also available from National Fire Protection Association, Batterymarch Park, Quincy, MA 02269. Fundamentals of Gas Appliance Venting and Ventilation, 1985, American Gas Association Laboratories, Engineering Services Department. American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209. Catalog #XHO585. Reprinted 1989.
- The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
- Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
- The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
- Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
- "Residential Steam Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
- "Residential Hydronic (circulating hot water) Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
- "Warm Air Heating Systems". Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
- Heating, Ventilating, and Air Conditioning Volume I, Heating Fundamentals,
- Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
- Installation Guide for Residential Hydronic Heating Systems
- Installation Guide #200, The Hydronics Institute, 35 Russo Place, Berkeley Heights, NJ 07922
- The ABC's of Retention Head Oil Burners, National Association of Oil Heat Service Managers, TM 115, National Old Timers' Association of the Energy Industry, PO Box 168, Mineola, NY 11501. (Excellent tips on spotting problems on oil-fired heating equipment. Booklet.)
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
- Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
|
The Home Reference Book - the Encyclopedia of Homes
|
- Links to our list of additional information on heating system inspection, repair, maintenance
- ...