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A 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 baseboardfs. Here we explain how to diagnose and repair problems with air bleed valves and we describe methods used to remove un-wanted, air from noisy or air-bound hot water heating system pipes, radiators, convectors, and baseboards. We illustrate how to buy and add air bleeders at baseboard elbows using a baseboard tee and air bleeder valves. Contact Us by email if you are having trouble finding the information you need.
Hydronic heating air vents and air purge devices: types, where to buy; How to diagnose and fix heating system noises & air in hot water heating system pipes. Service Procedures to force air out of an air-bound hot water heating system. How to bleed a hydronic (hot water) heating system: how to purge air out of heating system boilers, radiators, baseboards, or piping. What is a baseboard tee, how do they work with baseboard air bleeder valves, how to install air bleeders, vents, purgers.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
This article series is divided into these main sections:
Carson Dunlop's sketch (left) shows a common location for the air bleed valve on a cast iron radiator. The advice to leave this valve alone is intended for home inspectors who don't want to risk spilling water on someone's floor or opening a valve to find that they can't close it again. But if your hot water radiator or convector is staying cold even though the heating boiler is running and hot, it may be air-bound and you'll need to bleed out the air.
Why is it necessary to get this air out of heating lines?
Air trapped in hot water heating piping, radiators, baseboards, or convectors makes the heating system noisy with gurgling or bubbling sounds if there is just a little air in the heating system.
But if the volume of air becomes too great, the heating system will simply stop delivering heat to the occupied spaces, some or all of them, in the building. Why? A heating circulator pump is capable of pushing water around in the loop of heating baseboard but is often not capable of overcoming a section of baseboard that contains a large bubble of air. It's necessary to remove such air blocks. If air blocking has been recurrent a previous owner may have installed air bleeders at strategic points.
See Air Bleeder Valves for details about how to get an individual cold radiator working again if it's air bound, and see AIRBOUND HEAT SYSTEM REPAIRS if the cold radiator, convector, or baseboard problem seems to affect all of the heating radiation devices on all or part of an individual heating piping loop or zone.
Automatic air purge devices (photo at page top) are available and are usually installed right at the heating boiler but sometimes additional ones are needed at higher levels in the building.The two most common locations for automatic air bleeder valves on hot water heating systems are on top of the heating boiler itself (photo below right), or on a special air-scoop and air purging device found on the hot water heating piping just over or near the heating boiler (photo below left).
Check hot water baseboards, radiators, or heating convectors: if some of these heating devices are hot and others cold, are they all on the same heating zone? Feel the hot water piping leaving the heating boiler - it should be hot when the boiler is running and the thermostat is calling for heat.
If the building has multiple heating zones each zone will be controlled by its own thermostat and each heating zone will either have its own hot water circulator pump (controlled by a thermostat and pump relay switch), or each hot water heating zone will have its own thermostat and a zone valve that opens to let a common circulator pump send hot water through that individual heating zone. Are all of the thermostats turned up high enough to call for heat in each heating zone?
If some heating baseboards or radiators are hot and others cold and we're sure that they're on the same heating zone, then the system is probably air-blocked.
Virtually every hot water heating system has one or more air bleed valves installed. On most hot water heating systems there is at least one automatic air bleed valve, usually located on the heating boiler itself, or close to the heating boiler on a nearby check valve or flow controller.
Inspect and fix or replace any leaky float-type automatic air bleeder valves (air vents):
Inspect and use or replace manual air bleeder valves on the heat distribution piping:
How to Open Manual Air Bleeder Valves on Heating Radiators and Baseboards to Bleed Out Air - step by step guide
Here we describe the procedure for using manual air bleeder valves to remove un-wanted air in a hot water heating system in order to correct noisy gurgling pipes or to correct loss of heat due to an air-bound radiator, heating convector, or section of hot water heating baseboard.
If your hot water heating system has become air-bound (one or more sections of heating radiators or baseboards are staying cold even though the boiler is on and the circulator pump is running), and if your system does not have an air bleed valve to remove air blocking water flow, you probably need to call a heating service technician who will use one of the methods we describe at Airbound Heating System Relief Procedure.
Step 4: close the air bleeder valve. When water begins to come out of the valve, close it.
Step 5: feel the heating pipes entering the baseboard, radiator or convector. In a minute or so the pipes and radiator should begin to warm up and eventually become hot. If this does not occur either the heating system is off, there is another airbound location, or there is a separate problem with the heating system. In that case see HEATING LOSS DIAGNOSIS-BOILERS.
How Do we Know That the Air Bleed Valve Operation Has Been Successful?
Frequently Asked Questions (FAQs) about Hot Water Heating System Air Bleeders & Vents
Question: Where can I buy canister type air bleeder or air purge valves?
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
Reply: Identification Photos of Types Hydronic Heating (hot water heat) air vents or air purge valves & where to buy them
We distinguish among several types of heating system air bleeder valves or air vents:
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. .
Question: What's the difference between an air bleeder valve and a radiator on-off valve?
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.
A tricky way to "shut off" radiators in older homes by not bleeding air out of the radiator
Sometimes in older homes the heating radiator control valves are stuck and cannot be operated. Usually the radiator valve will be stuck in the "open" position because no one wants to live with no heat in cold weather. When we lived in a 100 year old home in Poughkeepsie, New York, ever fall we found that some radiators had become full of air over the summer when the heating system was off.
For a few rooms where we didn't want heat, and where the radiator control valve was "stuck" in the "open" position, we found that if we simply neglected to bleed air from that radiator it wouldn't heat up when the rest of the heating system was operating.
Over at RADIATOR VALVES & HEAT CONTROLS you'll see more photos of radiator control valves. On all hot water radiators the heating control valve that turns the radiator on or off will be at the hot water inlet pipe to the radiator and may be located near the radiator top or bottom. There are a few air bleeder valves that have a tiny round handle, maybe 1" in diameter, but they will be mounted right onto the radiator body itself, not on the piping.
Question: Installing air bleeder valves: how do I add a manual air bleeder valve on hot water heating baseboard piping
Hi Dan, How do I install a manual bleeder valve on my baseboard heating pipe? Can I tap into the 90 degree elbow with a 1/8 drill bit and sweat a bleeder valve? Are there any other alternatives to incorporate a manual bleeder to the baseboards in the house? - Simon.
Reply: Here is how to buy and install a Heating Baseboard Tee - a special 90 degree elbow that has a reinforced 1/8" NPT tapping and solder it in place at system high points
At left are the two baseboard tees I had purchased, along with their air bleeder fittings, ready for installation. The plumber (whom I am leaving nameless) left them on the floor - his real reason: he took a shortcut that saved maybe five minutes on the job by using the pex to copper 90's (with no tapping for an air bleeder valve) that he had on his truck.
When I complained, his retort was that air bleeders are not needed and that they were in his opinion a liability (because he fears they'll leak) rather than an asset.
While it's true that in a perfect world, with a combination of luck, Air Scoops Purgers Separators that magically capture 100% of problem air in the heating system, and perfect plumbing routing you can purge air from at least some hot water heating systems at initial installation. But it's just plain stupid to think that over the life of a hydronic heating system there will never be an air problem in the piping. It's not a perfect world, and "stuff happens", ya know?
So I do not agree with that plumber, nor do heating experts nor the manufacturers who produce a wide variety of valves to manually or automatically purge air from hot water heating systems. As we were installing a new heating loop on an upper floor addition on a one story house, it's likely that air entrained in the heating water or that appears in heating system ever in the future will rush upstairs.
Now I'm going to have to drain down the system and remove his work and install the proper fittings myself.
Stop by your local plumbing supplier. They can sell you a special elbow, a baseboard tee, usually bronze (see our baseboard tee image at left), that solders in place to replace the existing 90 degree elbow at either end of your baseboard run. The baseboard tee looks like a 90 degree elbow but technically it's "Tee" because it has three openings - the two 3/4" copper pipe fittings and a third 1/8" tapping that is installed pointing "up" to accept the bleeder valve. These are inexpensive fittings, typically around $4.00 U.S.
The baseboard tee or elbow includes a raised casting with additional bronze 1/8" NPT tapping already threaded to accept the bleeder fitting itself. Our page top photo shows a similar tee made of cast iron.
Under a heating baseboard cover, at the start or end of the baseboard run, because of space limitations (under the baseboard cover) and for reliability I prefer to use simple manual bleeder valves at baseboards - they're solid and bullet-proof.
Baseboard tees are also available for other types of heating piping systems such as PEX tubing, and in mixed sizes such as 1/2" x 1/8" x 1/2" and 1/2" x 1/8" x 3/4" diameters to fit the PEX, bleeder valve, and 3/4" diameter copper baseboard piping. If you are working with standard copper heat piping you probably need one or more 3/4 " x 1/8" x 3/4" baseboard tees.
When I was actually working for a living and had to try to fix air-bound heating baseboards in some older homes (see Air-bound boilers & radiators) it was standard practice to install at least one of these bleeder fittings at the highest point on any baseboard run that was giving problems.
My photo (left) shows a baseboard tee with an older type of air bleeder valve installed at a home where there had indeed been a baseboard piping leak. But the leak didn't occur at the air bleed valve, which had been safely shut.
The leak happened when the home lost heat and the piping froze and burst. You can see a section of new copper piping that had been soldered in place during repair work on the home.
You'll want to do he job if adding one or more heating baseboard tees and its air bleeder fitting before the heating season begins so that you won't mind shutting down and cooling off the boiler. You'll need to drain the heating line so that you can de-solder the old elbow and then solder the new baseboard tee in place.
I advise AGAINST drilling and tapping in an air bleeder into an existing elbow even though it's technically possible to do so. The worry is that the 90 is just too thin at the point where you'd drill; even soldering an air bleeder in place I would be forced to agree with my irritating plumber, that in that case the fitting would not be reliable. It's not worth a leak and water damage and mold contamination from a leak that will naturally happen while no one is at home.
Incidentally small amounts of air WILL circulate around through the system as bubbles and can get caught and vented by an air bleeder right at the boiler or its riser pipe. That's why you'll usually find an air bleed in that location. (See our page top photo).
Finally, if you take the annoying plumber's view, you can eschew any air bleeders and instead, wait until the system is air bound and you've lost heat.
Then one can, using boiler drain and feed fittings, force higher pressure through the system to try to blow air out of those uppermost heating baseboards. Of course that' a heck of a lot more trouble than just loosening a bleeder valve screw and letting the air hiss out at the high point(s) in the system.
At Air-bound boilers & radiators we discuss alternative methods for removing air from an air-bound system.
Question: Installing air bleeder valves: Advice for installing remote or secondary air bleeder valves
When installing an automatic air bleeder on a system is it possible to install a tee at the high point then run a line to a different location and install the auto air bleeder in the secondary location, and will it work if that secondary location is lower than the tee in the main line? - Steve
Reply: the high point air bleeder valves are most important on hydronic heating systems but air bleeders in other locations work also
Steve you will sometimes see automatic air bleed valves at various heights and locations on heating system piping, and all of them will work to release air that finds its way to each of those locations. However it's most likely most important to include an air bleeder at the highest point in system piping where air may be found.
Question: Installing air bleeder valves: Is it ok to install an air bleeder valve by just drilling and soldering into an existing copper pipe elbow on the heating line?
Reply: not recommended
Question: Installing air bleeder valves: which end of the heating baseboard gets the air bleed valve
Should the air vents be installed on the inlet or outlet of the baseboard heater? - Ron Thompson
Reply: at the outlet end or at both ends of the baseboard
Ron, if I were installing only one manual air bleed valve I'd certainly place it at the end of the heating baseboard so that I could force air out of that baseboard section.
On difficult or long baseboard runs I like to install bleed valves at both ends of the baseboard run. In that case I might install an automatic air bleed valve at the input end of the baseboard and a manual air bleed valve at the end of that baseboard run. In that manner, as long as the automatic air purge or air bleed valve keeps working air shouldn't enter the baseboard run.
But if air does get into the system, from a bad valve or from a sudden large surge of air, some of which gets past the front end air bleed valve, I can still purge the problem air from the system without having to follow other more complicated, lengthy, and expensive procedures.
Question: Installing hot water heating piping air bleeder valves: leave the bleeder cap loose?
There is a lot of great information here. Definitely helpful for some things and the images are also a plus.
I have cracked one of the valves and an ever so slight amount of air comes out but not enough to get the water flowing. I'm guessing I may need to bleed all the water from the system and start from scratch. I'm just glad that it appears to be an air blockage and not something more serious.
Reply: it depends on the air bleeder valve type
Finally, we can categorize air bleed valves on hot water heating systems into roughly two groups:
Automatic air bleeders, often including a float valve that drops to open the bleed valve to purge air when air accumulates in the float body - on these valves the manufacturer instructs to leave the valve cap loose so that the valve can vent automatically. An automatic air bleeder at the boiler or in a utility area should pretty much always have its cap left loose so that it can do its job.
Manual air bleeders, usually don't even have a cap, but might. These are kept closed except when in use.
Watch out: an automatic air bleed valve with a loose cap, installed on a heating baseboard in the living area, can present a risk of water leaks into the building floor (or ceilings below), if it's not inspected and if necessary cleaned or replaced. In this location some heating techs and plumbers avoid the leak risk by just keeping the cap tight on the valve. The valve won't automatically purge air (you are relying on other air purgers elsewhere in the system for automatic air purging), but it can still be opened and activated if necessary to purge air from the particular high hot water piping loop that it serves.
Question: installing heating piping air bleeder valves: do I need air bleed valves at both ends of the piping run?
My home has several zones with base board hot water radiator. the problem zone is divided by a stair case between two rooms. The plumber installed no bleeds. he simply made a 90 degree rise 7 feet to the top of the landing then across 10 feet to 90 degree 7 foot drop to the other room. This makes the 7 foot stair case landing the highest point for this zone. I now have an air lock. Do I put a bleeder valve on both the right and left side of the landing? (PS. .I am now very proficient at complex copper sweating.) Is there a rule dictating how short or long a run need to be before needing to add 2 bleeders. firstname.lastname@example.org
Melvin, I don't think you need two bleeders if you can get one at the end of that high point in the piping - by "end point" I mean that for that high horizontal run, put a bleeder at the end of the run (where the pipe heads back down) that is more distant from the boiler feed side. That is, it's on the "return" end of that high leg.
A [lumber friend came by said the same thing you said Dan. However, we both feel sometimes saving $6.00 costs hundreds or thousands. So we ended up just placing bleeders at both ends of the high point. I tested your theory by filling the system and only bleeding system using the valve installed at the return side bleed and the system worked.
Reply: plumber shortcuts on heating piping diameter and air bleeder valves cost plenty later
I agree with you completely. The owners and contractor were disgusted when Paul A., somewhat of a bully plumber in Poughkeepsie, saved himself some labor time and "saved" the customer essentially nothing by installing smaller diameter hot water heat supply piping to and from a building addition.
Paul also saved himself labor time by refusing to install two air bleeders on the high loop in the system even though we bought the bleeders and left them on the floor at the locations where they were to be installed. When questioned he explained that "half-inch heating piping is just fine, and you don't want those bleeders anyway - they're a liability - they always leak".
The smaller heat supply piping he used failed to consider the design specifications for the heating system - an assumed hot heating water flow rate through the baseboard, combined with a high-output heating baseboard design had permitted the use of about half the normal linear footage of baseboard in the room. Now if the heat is found to be inadequate the owners will have to either ruin their design by adding baseboard, or they'll have to rip out ceilings to install larger diameter heating water piping.
And about leaving off those air bleeders: sooner or later over the life of the building, when that high heating pipe loop becomes airbound, the occupants will have to hire a heating or plumbing tech to go through a more troublesome (and costly) procedure to fix the airbound heat problem. If Paul had taken the trouble to make a first-class installation, one could have just opened a screw and bled out the air in minutes.
Question: Winterizing the heating system: Is it OK to drain un-used heating zone piping, baseboards and radiators?
I have a boiler with 5 heating zones. I am living alone in a big house and do not use the rooms for 3 of the zones. I would like to know if I can drain those zones so they don't freeze and just use the 2 remaining zones for heat.
Sure, provided your heating zones are individual piping loops, and that you have control valves at both ends of the un-used heating zones, you can drain them and leave them turned off.
Question: Winterizing the heating system: Can I put antifreeze in the heating system instead of draining it?
I've read the other parts of your website as you suggested and I hope you don't mind more questions. Instead of trying to drain the heating zones I don't need, can I just put a non-toxic antifreeze in the whole boiler system? It sounds easier if it is a good solution.
Reply: use an antifreeze intended for use in heating boilers and piping
Sure, there are specific antifreeze products intended for use in hot water heating systems. Also see WINTERIZE A BUILDING
Question: Heating Zones: How can I determine how many heating zones I have?
I took a look at the boiler. I see the 5 zones going off the outbound pipe, but I only see 2 converging back to the intake. Do you think that means the zones are not all individual loops? - Lisa
Most likely you have
Question: Winterizing the heating system:Can I shut off the first radiators in the heating zone without losing heat in the rest of the house?
I have such a system, and only one zone. The thermostat is located in the warmest room in the house. Causing frigidity and numbness of extremities in other areas of the home. Since the location of the thermostat is also where the first radiator is in the home, can I "shut off" that baseboard radiator, and the next one, without losing heat to the rest of the home? - Jacke
Reply: It depends ... on how heating piping is arranged
Question: how do I solve problems with leaks at an air bleed valve and air remaining in the heating system?
I recently installed a new hot water furnace in my house. I did the job myself and everything is working ok except that the automatic vent valve constantly needs to be opened to let out air. I left the cap loose so that it could vent automatically but then it leaked. Do you think that the valve is bad or is not placed in the proper location ? Any help would be appreciated. - E.M. 12/27/12
A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with air bleeding or air leaks into hot water heating systems. (Incidentally, for clarity we call hot water heating systems heating boilers or hydronic boilers - furnaces are generally warm air heating systems).
That said, if you are continually seeing air bleeding out of your air bleed valve then I suspect that either you have not fully bled all air out of the system or there is a leak somewhere that is both letting water out and air in. I suggest checking all of the heat piping, baseboards, radiators &c. to see if everything is getting hot; if your system is successfully circulating hot water through all of the piping and heating devices but there is still air in the system (and if there are no leaks) then it should be pretty easy for the automatic air bleeders (properly located at high points on the boiler and on the heat distribution piping) to purge the remaining air.
I do not think that noting air coming out of an air bleeder is any indication of a faulty air bleed valve.
And if you are indeed seeing air venting out of the valve its location is a functional one. However that does not mean that it's the only air bleed valve needed.
does a spirovent eliminate the need for baseboard vents? - plw65 11/18/11
Question: bled air but still get gurgling sounds - where will I find secondary air bleeders
I have an under 10 year old baseboard hot water radiator system. I bled the main tank at the furnace but am still getting gurgling and water flowing sounds in some of the radiators. I assume there are secondary bleeder valves. Where are the likely places these might be located. Thanks - Jim 1/30/12
AIRBOUND HEAT SYSTEM REPAIRS has more thorough and aggressive means to get unwanted air out of a hot water heating system.
Question: Leaky air bleeder on a Slant-Fin "radiator"
We live in a 45-year old house with baseboard Slant-Fin radiators. One of the airbleeder valves has started to leak, It's a slow leak. but enough to do some real damage if we don't fix it. Upon inspection, we found that all the bleeder valves in the house are horribly corroded and would like to have them replaced. I don't want to attempt this myself (I'm somewhat handy, but the thought of screwing up and losing our heat in the middle of the winter is horrifying) So what kind of specialist should I call? - Dave Selander 3/4/12
A heating service technician or a plumber experienced with hot water heating piping can do the job you describe. It's least disruptive to schedule the repairs for out of the heating season.
Question: I want to shorten a 24-inch air bleeder valve
I have a bleeder valve that is 24 inches tall and would like to shorten it to 12 inches. Can a plumber specializing in hot water heating do this job or do you advise against? Thank you - Thierry Neubert 4/20/12
Theirry I'm not sure it's safe for us to diagnose and prescribe for your heating system with so little specific detail. In general you're talking about a simple plumbing job, changing out a length of pipe for a shorter one. But check with your heating service technician to be sure that there is no specific need for a 24-inch tall riser pipe.
how do i add antifreeze to my boilers baseboard heating system - Gene Griswold 7/22/12
Gene, please search InspectApedia for
Question: cold wall panel
Wall panel hot at top but cold at bottom. Cause and remedy please - John 7/29/12
John, so little information, sorry, no idea. I don't even know what kind of heat you are discussing.
Question: nothign comes out of the air bleeder valves
Hi - I have baseboard water heat. Nothing comes out of the air bleeder valves (All but one is manual, they fit a flat head screwdriver.) I just ran water through the whole system to get rid of all the air bubbles. The pressure on the little gauge looks good and pretty consistent. Now the pipes seem to be hot, but still when I open the bleeder valves I get no water and no hiss of air. Is this normal? Is it ok? Do I need to do something?
If no water comes out of the air bleeder valves I suspect the valve body is clogged or blocked.
Question: can't open the air bleeders on some of my radiators
The bleeding screw in some of my radiators have rounded off so cannot unscrew them. Can I buy replacement plugs and if so would they be simple to fit myself. Combi boiler system.
Maggie I have two possible solutions to rounded-off air bleed screw fittings.
First, try using a mini Vise-Grip tool that can reach inside the opening of the air bleeder and get a good bite on the air bleeder. I've successfully opened, bled, and closed tight air bleeders in this condition, allowing us to defer replacing the device.
The other solution is to shut down heat, cool down the system, and replace the entire air bleeder. Prepare the new replacement unit with teflon tape or pipe dope. Put down a towel, Remove pressure from the system (but you shouldn't have to actually drain it), work fast, and don't cross-thread the new fitting.
Question: can I change a manual air bleeder to an automatic one
Can an automatic bleeder be screwed in where the manual bleeder is on my radiator or will i have a puddle of water on my floor when auto bleeder starts working? - Darrell 11/20/12
Yes you can change a manual air bleeder to an automatic one provided you choose a device that works in the position in which you need to mount it.
You are correct to worry about unintended leaking, since most automatic air bleeders require (to work) that their screw cap be left loose. So it makes sense to use these conversions where someone will quickly notice if there is a leak, and to avoid them otherwise. In my OPINION.
Question: I don't think my vents are working
I have this type of radiator inspectapedia.com/heat/Heat_Convector173-DFes.jpg. For someone reason the one closest to the boiler needs to be bled every day. I do not see any leaks. All other radiators function fine. It is a one floor house with one zone. Any thoughts? - Chris 1/3/13
I have three automatic air vents - one Spirovent and two Hy-Vents for three paralleled heating needs off oil-fired boiler. Former is on main whole-house distribution loop for Infloor radiant heating and one of latter is for DHW storage tank distribution loop. The last is on the far-side distribution loop of heat exchanger for sunporch with Infloor radiant heating. This loop has 50:50 mix with antifreeze because the temperature control is set for 50 degrees in Gypcrete slab temp and not air temp in glass/extruded aluminum sunporch.
This automatic air vent seems not to be working automatically anymore because this heating season I'm hearing entrained air 'tinkling' and 'squirting' through the circulator pump. Even with pressure checked at 20 PSI. This vent sits atop Taco air scoop with expansion tank under scoop and these three are downstream of pump which is piped in very soon after boiler outflow manifold. I have checked that screw cap cover is backed off and have now depressed Schrader valve to release a 'highly carbonated' bubbly froth three times today and still haven't gotten all air out. Other Hy-Vent on piping to DHW tank delivers only water when I depress Schrader valve. Can I clean this [faulty] unit without depressuring that loop? If so, how do I take it apart. Taco manuals I've found show nothing. Just replace it? Is the antifreeze to blame? Specifications said I could use it. Suggestions welcome. - Christopher D'Amico 1/14/2013
Christopher I think you might first take a look at AIRBOUND HEAT SYSTEM REPAIRS where we describe methods to be sure you've gotten all the excess air out of all of the system components and piping.
Question: what about adding air vents at baseboards - is that a good idea? What about using Sharkbites for fittings?
I noticed that you said automatic air bleeders are typically installed at or near the boiler/expansion tank and that you only mention manual set ups at the baseboard. Do you advise against installing automatic air bleeders at the baseboard? Second, my install is nearly all pex, have you found a source for 3/4" pex x 3/4" pex x 1/8" female npt tees? I've ben unlucky thus far. Finally, I'm planning on using sharkbite push/fit connections anywhere possible, they max out at 200 degrees, while my system will generally be about 170 degrees. Do you advise against using sharkbites in this application? - Bobbito 1/23/13
I like to install manual air vents (automatic ones are nice but I've seen a few leak complaints) at the highest run of heating baseboard as well as at the start or more often the end of any runs of baseboard with a history of becoming air bound.
We have used sharkbite type fittings on heating systems as well as PEX tubing with no problems, operating at 180F.
Question: how do I add an air vent if there is no room for a vertical pipe at the boiler
how install auto air vent if no 18 inches horizinatal pipe possible? - Air Vent Installation 3/31/2013
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