Hot Water Radiator Air Bleed Vent Installation FAQs

Diagnostic Q&A on Installing or Adding Hot Water Heat Air Bleeders, Eliminators, Vents

Where to Install Air Bleed Valves FAQs

Tip: see

• NO AIR BLEEDERS or AIR VENTS FOUND on HEATING SYSTEM
• HOW TO REPLACE AN AIR BLEEDER VALVE or FLOAT VENT

Where should I Install extra air bleeder valves on my hot water heating system?

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.

You can run a tee at a high point, as in your question, and then add a more remote air bleeder, provided that all of the piping slopes horizontally or better, uphill from the tee.

Small amounts of air in a hydronic heating systems are sometimes pushed around by the circulating water and may reach even lower air bleeders.

But the circulator can't push large amounts of air - the system can become air bound unless means are provided for getting rid of it.

Also see AIR BLEEDER VALVE FUNCTIONS

For eliminating air from potable water, cold water or hot water supply systems see AIR ELIMINATORS for POTABLE WATER SUPPLIES

Does the air eliminator at the boiler mean I don't need vents at the baseboards?

Does a Spirovent™ eliminate the need for baseboard vents? - plw65 11/18/11

Reply: No.

No. While an automatic air eliminator at the heating boiler will usually avoid an airbound heating system, leaks or work on the heating system or even bacterial growth can cause air accumulation along heat piping runs, particularly in longer horizontal runs without much pitch.

We usually need at least one air bleed valve at the high end of the heating piping, and we often need to add a bleed valve to remove air from tricky or long baseboard or piping runs.

You can install a new system with no air bleeders involved, and the heating system may work perfectly for many years. But sooner or later the system will need air purging.

A properly located manual air bleeder makes this job quick and trivial. Without it there are still ways to fix the problem

See AIR BOUND HEAT SYSTEM REPAIR by PUMP

and AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE)

but with more trouble and at a greater cost.

When 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. melvincoke@yahoo.com

Reply:

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.

Then with the bleeder in place, when the system is up to operating temperature and pressure, if you open the bleeder, the system pressure should push the air out.

Recapping: I like bleeders at both ends of high runs myself, but in truth you should be ok with just a bleeder at the far end from the feed side of the boiler.

Let us know how it goes - the results will help other readers.

Follow-up comment:

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.

So thanks very much for your help.

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.

Where does the air vent go when installing a new radiator?

When installing a new hot water rad to a existing house, does the vent go on the supply side or return side of the pipes below On 2019-02-14 by dave

Reply by (mod) - does the vent go on the supply side or return side

On the higher side of the radiator, convector, or baseboard used for hot water heat.

Where Does the Air Vent Go on a Heating Radiator - FAQs

Tip: See HOW TO REPLACE AN AIR BLEEDER VALVE or FLOAT VENT

Above: a hot water heating system air vent on a hot water heating pipe elbow.

Below: a typical steam vent on a steam radiator.

Where are the bleeder valves on a steam radiator?

Where can I find the bleeding valve on a steam radiator? On 2019-01-31 by roy

by (mod) - steam radiators vent air, not water

Roy

The air bleeder or air removal devices discussed here are for hot water heating systems, not for steam heating systems. But indeed steam radiators and piping also get their own steam vents.

Using the on page search box just above to search for STEAM VENTS finds

a series of articles on steam radiator vents beginning at

STEAM VENTS, 1-PIPE SYSTEMS

- found on one-pipe steam heating systems. Steam vents work automatically to remove air (not water) when steam is rising in the heating pipes and radiators;

These vents are not found on hot water (hydronic heating system) pipes and radiators - the subject of this page

Above: an Aeral 507 air vent that can be added to a hot water heating radiator by replacing the radiator's upper end plug.

How to Add or Install Air Bleeder Valves on Hot Water Heat PIpes

Tip: See HOW TO REPLACE AN AIR BLEEDER VALVE or FLOAT VENT

Is there an easier way to get elbows and air bleeder fittings onto my hot water heating pipes without having to drain the whole system?

I have an old boiler system / baseboard heating in a 3 story townhouse with very high ceilings and no bleeder valves. Needless to say my baseboards sound like Niagara Falls in the winter and i can only imagine how much air is in the pipes on the top floor where most of the bedrooms are.

Actually I do now have 2 bleeder valves as of recently when we had to move a base board and drained the system. I stuck them on the loudest spots that I could access easily. It certainly helped in those spots.

However getting that 90 degree drain valve (pic below) in there while de-soldering the old joint on the pipe return bend was a huge PIA and I almost destroyed the piping getting the pieces apart. Not looking forward to doing the other 8 like this.

A contractor I know recommended I use a straight union drain piece (same as the other one but no 90 degree bend) where I can just cut into the pipe and solder it straight in.

No melting old joints or risk being stuck with a bit of water in there making it impossible.

However I am worried this would not be really effective releasing air as it is not in a corner where air can collect. Curious if anyone has tried this method or know if it is a viable option.

Thanks!O n 2021-02-02 by Alex B

by (mod) - Use SharkBite elbows with 1/4" NPT drain for air bleeders on hydronic heating systems.

Alex:

Good news: you can use SharkBite fittings that let you simply cut the copper baseboard tubing and press-fit the necessary connectors to install elbows, bends, or whatever's needed,

That avoids having to try to de-solder and that might work for you if you can find the space to add air bleeder elbows at the high or entry or exit (or both) ends of your baseboards.

Below I'll show the part you want: the SharkBite 3/4" push-to-connect elbow fitting with drain; position the elbow so that the "drain" faces "up" for best result.

Also install air bleeders (float type automatic) right at the heating boiler on the supply and return ends of the circulating loops.

Watch out: you can use SharkBite fittings on hydronic heating up to temperatures of 200°F - which ought to be at or below any residential hot water heating system HI LIMIT.

 

 

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?

Hi Dan,
I've hired a HAVC guy to put replacement slant-fin baseboard heaters. because some of the stubs are coming from the wall, he claimed that he can't install a regular bleeder but have to drill a hole on the elbow and solder one in place. Is this the right way to do it? thanks. - Lily

Reply: not recommended

Lily

My OPINION is that drilling and soldering a bleeder valve into an existing copper elbow is an unreliable "fix" to add an air bleeder - the risk is that the soldered fitting is not strong enough and that you have a leak, worst when no one is home - and a flooded building and costly repairs.

Drilling a standard copper or bronze elbow to try to tap in a 1/8" diameter vent is likely to lead to leaks and maybe costly damage to building later on.

If it were my house I'd cut away the wall and solder the necessary fittings (called a baseboard tee and illustrated at the top of this page) in place, or I'd look a second time to see if there is not another location that will do.

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.

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

Reply:

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.

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

Reply:

Bobbito,

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.

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 horizontal pipe possible? - Air Vent Installation 3/31/2013

Reply:

Air


I've seen people try drilling, tapping, soldering, gluing an air vent right into a pipe - that's not a reliable plumbing connection and I DO NOT recommend it.

I DO advise installing air bleeders at some critical baseboard locations, especially if there has been a history of particular hot water baseboard sections becoming air bound.

If I didn't have a specific problem hydronic heat baseboard section I would still like to see an air bleeder vent installed at the start or end of the highest baseboard section in the building or on each heating loop.

There are automatic air bleeders that work unattended, but because some have reported leaks at those devices you might install a manually operated bleeder at the baseboard start or end elbow - the necessary fittings are a completely common part available at all plumbing and HVAC suppliers.