Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
AIR CONDITIONING & HEAT PUMP SYSTEMS
BACKDRAFTING HEATING EQUIPMENT
BACKUP HEAT for HEAT PUMPS
BANGING HEATING PIPES RADIATORS
BLOWER FAN OPERATION & TESTING
BOOKSTORE - InspectAPedia
BTU USAGE MONITORS
CARBON MONOXIDE - CO
CIRCULATOR PUMPS & RELAYS
DIAGNOSTIC GUIDES A/C / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DRAFT REGULATORS, DAMPERS, BOOSTERS
DUCT SYSTEM & DUCT DEFECTS
ELECTRIC MOTOR DIAGNOSTIC GUIDE
FAN, AIR HANDLER BLOWER UNIT
FLOODED HEATING EQUIPMENT REPAIR
FLUE SIZE SPECIFICATIONS
GAS BURNER Flame & Noise Defects
GAS PIPING, VALVES, CONTROLS
GEOTHERMAL HEATING SYSTEMS
HEAT PUMPS, DIAGNOSIS, REPAIR
HEATING COST SAVINGS METHODS
HEATING OIL PIPING TROUBLES
HEATING OIL TANKS
HEATING SYSTEM NOISES
HEATING SYSTEM TYPES
GAS LP & NATURAL GAS SAFETY HAZARDS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
MOTOR OVERLOAD RESET SWITCH
NOISE, HEATING SYSTEMS
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FILL PIPE LEAKS
OIL SPILL CLEANUP / PREVENTION
PLASTIC Plexvent / Ultravent RECALL
PUFFBACKS, OIL BURNER
RELIEF VALVE LEAKS
Reset Switch - Heater Primary Control
RESET SWITCH - ELECTRIC MOTOR
Reset Switch - Stack Relays
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOOT on OIL FIRED HEATING EQUIPMENT
STEAM HEATING SYSTEMS
THERMOSTATS, HEATING / COOLING
VIDEO GUIDES: Heating System Videos
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
ZONE VALVES, HEATING
Air bleeder valves & automatic air purging valve types, choices & sources: where & how to buy and add air bleeders at baseboard elbows using a baseboard tee and air bleeder valves. We list the manufacturers and most models of manual & automatic air vents, bleeders, float vents, canister vents, and hot water piping or radiator or boiler air vents.
This article series provides a detailed guide to using air bleed valves to get rid of unwanted air in hot water heating systems: fix cold or noisy hot water heating radiators or baseboards.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
We are unable to find the air bleed valves that you have listed on your web page (canister type)
We are looking to buy 10 of them and am wondering if you have a contract from which to purchase these?
Appreciate any help you can provide.
W.M. - Wacol, Australia
For a description of the different types of air bleeders or air eliminating valves see AIR BLEEDER TYPES & LOCATIONS.
Where to Buy Air Bleeder Valves or Automatic Air Purging Valves & Air Eliminators
There are several manufacturers in the U.S. and Canada who provide both automatic and manual air vents for hydronic heating system, as we list below. Some of these manufacturers have world-wide operations as we indicate below. You may need to use a different term that is country dependent when searching for these products, such as air eliminator. .
What's the difference between an air bleeder valve and a radiator on-off valve?
Reader question: how do I differentiate between the valve to bleed the baseboard radiator of air, and the on/off valve? I just bought my house and I notice that there are 3 baseboard radiators in one section of the house that are cold. I think that perhaps they are turned off, but I don't know how to tell. Looking at the radiators, they have pull chains coming out of the top louver, but there's no tension on the chain like there is when you use a pull chain to turn on and off a light, so maybe the pull chains are for opening and closing the louvers?
When I take off the lower cover, the part that covers the fins, I see a valve on the pipe where the water comes in (or out?) that has a slot for a flat-head screw. Would I use that to turn on or off the radiator, or is that the bleed valve? I think it must be the former because I don't see where air or water would escape.
Reply: How to tell an air bleed valve from a radiator control valve ?
At left we show a manual hot water heating radiator air bleeder valve that has a round black handle. Because of the handle shape some folks may be confused about just whether this valve is an air bleeder control or a radiator on-off valve.
But it's easy to see the difference. The valve shown at left is attached directly to the hot water heating radiator at its top at one end. It is not connected to hot water piping, so it cannot be controlling the flow of hot water into the radiator.
Now for more details:
At below left we show a common radiator control valve found at the top of a hot water radiator. Other radiator control (on-off) valves may be located close to the floor at the bottom of both steam and hot water radiators.
At below right our sketch (courtesy Carson Dunlop Associates) illustrates an air bleed found at the top of some older radiators - a model that has a tiny round handle. The advice in the sketch to leave air bleed valves alone is for home inspectors.
The worry is that opening an air bleed valve could lead to a leak if the valve is damaged or defective. But in fact manual air bleed valves on heating radiators are a control intended for use by a homeowner, need to be functional to get an airbound radiator back into operation, and need to be fixed if they're defective. The reason a home inspector might not operate the valve is that during a home inspection s/he doesn't want to risk starting a leak that can't be promptly shut off.
Other air bleeder valves have a t-handle or a square fitting operated with a "skate key" wrench and still other air bleeders use a flat bladed screwdriver for their operation - illustrated in the article above on this page. In the sketch at above right you can see the radiator on-off control valve at the lower right. Notice that the radiator control valve will always be connected to both the radiator and a hot water (or steam) pipe, while an air bleeder valve will be connected directly to the radiator.
Well almost. Our photo at above left is tricky because that particular model of radiator control valve also happens to include a little bleeder fitting - that hexagonal brass nut shown at the center of the radiator control valve body.
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: where can I buy a replacement air bleeder valve knob for an air vent like the one shown at the top of this article?
I live in Canada (Winnipeg, Manitoba) the picture below is the type of radiator I have, however the problem I have is that the round black knob for the bleeding of the air vent is missing from all 3 of my rads, so therefore I cannot open the value to let the air out . . . I have searched everywhere to be able to buy these knobs and cannot find anywhere to buy them . . . I am hoping the you can direct me to where I may be able to purchase these knobs. I am desperate. Thank you and I look forward to your reply - M.B.C., Winnipeg
One can usually open one of these old-style air vent valves without its control knob attached by any of the following means:
If the original valve stem is in good shape, your local plumbing or hardware supplier may be able to supply a generic replacement valve handle that will fit onto the existing stem. If not,
Use a small adjustable wrench if the valve stem remains roughly square;
Use a small Vise-Grip™ tool to pinch, hold, and turn the valve stem if it has lost its original shape.
Best solution: replace the old air vent with a new one, sized to screw right into the same opening as the old radiator vent valves. (The best time to do this is with the heat shut off and cooled down to avoid getting scalded by hot water and to minimize the water spillage. An expert heating technician can assist by temporarily dropping heating system pressure so that the old valve can be removed and the new one installed with minimum water spillage. See AIR BLEED VALVE LEAK REPAIR for air vent replacement procedure and details.
Try the search box just below or if you prefer, post a question or a comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.