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Mobile View HEATING SYSTEMS ANTI SCALD VALVES BACKFLOW PREVENTERS BAROMETRIC DAMPERS BLUERAY Recall BOILERS, HEATING BOILER CONTROLS & SWITCHES Air Bleeder Valves Air-bound boilers & radiators Aquastat Functions BOILER LEAKS CORROSION STAINS BOILER OPERATING PROBLEMS BOILER PARTS LIST Boiler Pressure Controls & Settings Cad Cell Relay Switch Flame Sensors Circulator Pumps & Relays Draft Regulators, Barometric Dampers Expansion Tanks Gauges on Heating Equipment Limit Switches, Boilers Low Water Cutoff Valves, Boilers Mixing Valves Pressure Gauges, Boilers Relief Valves - TP Valves Reset Switch - Primary Control Reset Switch - electric motors Spill Switches Stack Relay Switch Water Feeder Valves, Hydronic Zone Valves BOILER LEAKS CORROSION STAINS BOILER NOISE SMOKE ODORS BOILER OPERATING PROBLEMS BOILER OPERATION DETAILS BOILER PARTS LIST BOILER PRESSURE SETTINGS CARBON MONOXIDE/DIOXIDE CARBON MONOXIDE WARNING CHIMNEY INSPECTION DIAGNOSIS REPAIR CHIMNEYS & Flues - Asbestos Transite Pipe COMBUSTION GASES & PARTICLE HAZARDS COMBUSTION PRODUCTS & IAQ DEFINITION of Heating & Cooling Terms DRAFT HOODS - gas fired DRAFT REGULATORS - barometric dampers COOL OFF HEAT Thermostat Switch DRAFT REGULATORS - barometric dampers DUCT SYSTEMS DUST FROM HVAC? ELECTRIC HEAT ELECTRICAL POWER SWITCH FOR HEAT ENERGY SAVINGS in BUILDINGS ENERGY SAVINGS PRIORITIES ENERGY SAVINGS RETROFIT CASE STUDY ENERGY SAVINGS RETROFIT LEAK SEALING GUIDE ENERGY SAVINGS RETROFIT OPTIONS FLUE VENT CONNECTORS FREEZE-PROOF A BUILDING FURNACES, HEATING FURNACE CONTROLS & SWITCHES FURNACE OPERATION DETAILS GAS PIPING, VALVES, CONTROLS HEAT EXCHANGER LEAKS HEAT LOSS in BUILDINGS HEAT LOSS DETECTION TOOLS HEAT LOSS INDICATORS HEAT LOSS R U & K VALUE CALCULATION HOUSEWRAP AIR & VAPOR BARRIERS HEATING COST SAVINGS METHODS HEATING LOSS DIAGNOSIS-BOILERS HEATING LOSS DIAGNOSIS-FURNACES HEATING OIL CLOUD WAX GEL POINT HEATING OIL EXPOSURE HAZARDS, LIMITS HEATING OIL SLUDGE HEATING SMALL LOADS HEAT PUMPS HEATING SYSTEM INSPECTION PROCEDURE INSULATION & VENTILATION INSPECTION & IMPROVEMENT MOTOR OVERLOAD RESET SWITCH NO HEAT - BOILER / FURNACE DIAGNOSIS ODORS FROM HEATING SYSTEMS OIL BURNERS OIL BURNER INSPECTION GUIDE OIL BURNER NOISE SMOKE ODORS OIL BURNER SOOT & PUFFBACKS OIL FUEL TYPES & CHARACTERISTICS OIL TANKS OIL TANK GAUGES OIL TANK SLUDGE OIL TANK TESTING OIL TANKS, BURIED PLASTIC HEATER VENT RADIANT HEAT RADIANT HEAT Floor Mistakes to Avoid RADIANT SLAB FLOORING CHOICES RADIANT SLAB TUBING & FLUID CHOICES RADIATORS RELIEF VALVES - TP Valves on Boilers Relief Valves - Water Heaters SAFETY DURING HEATING INSPECTION Safety Recalls BLUERAY Recall CHIMNEYS & Flues - Asbestos Transite Goodman HTPV RECALL Heat Recovery Ventilator RECALL Lennox Furnace Manuals Lennox WARNING Weil McLain RECALL SPILL SWITCHES STACK RELAY SWITCHES STEAM HEATING SYSTEMS Cad Cell Relay Switch Flame Sensors Circulator Pumps & Relays TANKLESS COILS THERMAL EXPANSION of MATERIALS THERMAL MASS in BUILDINGS THERMAL MASS in UPSTAIRS THERMAL TRACKING & HEAT LOSS THERMOSTATS Transite Pipes, Chimneys & Flues More Information InspectAPedia Blog - News Updates Air Conditioning & Heat Pumps Bookstore Electrical Environment Exteriors Heating Home Inspection Insulate Ventilate Interiors Mold Inspect/Test Plumbing Water Septic Roofing Structure Accuracy & Bias Pledge Contact Us |
Here we discuss the various 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. If radiators on the upper floors of your building are not getting hot, check that the heating system operating pressure is at the proper setting, and check that you radiators are not air-bound - see Air Bleeder Valves. Also be sure that your circulator pump and zone valves (if any) are working properly. If your heating system uses a steam boiler, see Water Feeder Valves, Steam. If you don't know what kind of heat your building uses, see our introduction at BOILERS, HEATING. If your heating system is not working properly, see NO HEAT - BOILER / FURNACE DIAGNOSIS.This website answers nearly all questions about Heating System Boiler Controls on central heating systems to aid in troubleshooting, inspection, diagnosis, and repairs. 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. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website. Hydronic (hot water) Heating Boiler Water Feed ValvesManual 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 is an automatic pressure-reducing & water feed valve for a hot water boiler. An arrow on the valve base shows the direction of water flow (from building supply at right into the boiler at left). 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 device to the right of the automatic water feed valve 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. An automatic water feeder used on hot water heating boilers performs two functions:
The automatic water feeder has two additional features:
Photo Guide to Heating Boiler Pressure Reducing Valves
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. 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 shows in this 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?
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
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. 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.
Steam Boiler Water Feeder Valves, Automatic & ManualKeeping 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. 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. But 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. Automatic water feeder valves on steam boilersAutomatic 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. But because the steam boiler will be damaged or unsafe if its water level falls too low and because it's normal for a steam system to use (lose) water, the water feed valve on a steam boiler has to operate more often, and will be a more heavy-duty (and probably reliable) device. The black box shown in our photo at left is a Mcdonnell & Miller™ automatic water feed valve. On a signal (normally from the low water cutoff valve) the water feed valve will open to send additional makeup water into the steam boiler. Manual water feeder valves on steam boilersIn our photo at automatic water feed valves, an automatic water feeder is installed (the black box discussed below). But the yellow handle is an manual water feeder that will bypass the automatic water feeder and force water into the boiler. On this particular system you shouldn't need to use the manual feeder lever unless the automatic feed valve is broken. As you see, the yellow handle is in the horizontal position, "across" the water pipe, showing that it is in the "closed" position (we're depending on the automatic feed valve). But on lots of steam boilers, especially older residential units, you may find that only a manual feeder valve is installed. You'll need to use it whenever the steam boiler water level is low (discussed below). How often you'll need to manually add water to a steam boiler that lacks an automatic feeder depends on how rapidly your particular steam heating system loses water. If you are new to your particular steam heat system, you should check it's water level (and flush the low water cutoff valve) at least weekly until you know more accurately how the heating system behaves in normal use. 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 Much Water Should Be Added to a Steam BoilerIf your steam boiler has an automatic water feeder you should see the water level always close to the fill-mark and the automatic water makeup valve will normally do this job for you. If your steam boiler has only a manual valve for adding water, until you know the system's rate of water usage, you should check the water level at least once a week during the heating season. You'll want to add water whenever the sight glass shows that the water level has dropped to the "add" mark and you should always see some water in the sight glass. The sight glass on a steam boiler, combined with a mark or gauge usually placed on the sight glass or on the boiler body behind the glass, will show the proper level to which the steam boiler should be re-filled when it's low on water. See Sight Glass, Steam Boiler for details of this component.
Our discussion of radiators or baseboards that do not get hog when they should includes these key sections:
Readers should also see Diagnose Oil Heat Noises for diagnosis and repair of other heating system noises on both oil and gas fired heating equipment. This website answers most questions about central heating system troubleshooting, inspection, diagnosis, and repairs. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. If you don't know what kind of heat your building uses, see our introduction at BOILERS, HEATING. If your heating system is not working properly, see NO HEAT - BOILER / FURNACE DIAGNOSIS.This website answers nearly all questions about Heating System Boiler Controls on central heating systems to aid in troubleshooting, inspection, diagnosis, and repairs. ... Technical Reviewers & References
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website. HEATING SYSTEMS
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01/25/2009 - 09/05/1999 - InspectAPedia.com/heat/WaterFeeders.htm © 2009-1999 Copyright Daniel Friedman All Rights Reserved - InspectAPedia® is a Registered U.S. Trademark