Knowing how to bleed air from baseboard heating systems is the main solution to one of the most common problems in hot water and other hydronic baseboard heating systems – trapped air in the pipes.
This problem can be easy to identify by the loud noise in the system’s pipes every time water passes through them and the trapped air. It’s quite a significant problem as it doesn’t just make your baseboard heating system noisy it also makes it run less efficiently and can turn it completely ineffective if the problem isn’t fixed.
How to get air out of baseboard heating systems?
Bleeding baseboard heating system is fairly straightforward but it does have its tricks.
- Turn your baseboard heating system on. It may be intuitive to turn it off before you tinker with it but you actually need it to be running for the bleeding to be possible.
- Go to the baseboard radiator that’s farthest from the boiler and locate its bleeder valve. It’s in different places on different units but it’s usually near the top of the radiator. It’s small and inconspicuous most of the time and it’s designed to be turned either with a radiator key or with a simple flat-head screwdriver. Take a bowl or a large cup and position it under the valve. Once it’s in position, take the radiator key or an appropriate screwdriver and start turning the valve counter-clockwise. Don’t turn it all the way, just a little bit so that small amounts of water start “bleeding out”. You’ll notice air coming out of the radiator together with the water – that’s the air you want to get out, not the water itself.
- Once there’s no more air coming out of the valve and it’s only dripping water into the bowl, turn the valve back clockwise.
- Go to the next radiator that’s closer to the boiler and repeat the process. Do this for all radiators in your baseboard heating system, leaving the one closest to the boiler for last.
Congratulations, you now know how to bleed baseboard radiators.
How to bleed baseboard heat without bleeders?
If you’re unlucky enough to have a particularly old baseboard heating system you may encounter the problem of not finding any bleeder valves on your radiators. If that’s the case you should look for any valve anywhere along the system. Some systems have valves hidden in completely absurd places such as at random points along their pipes or somewhere in your bathroom or basement, usually hidden behind something.
Other systems will have an automatic valve or vent on the boiler itself or on the pipes that exit the boiler. Bleeding your entire system from one place will take time and won’t be as effective but if that’s the only option your system allows you, then that’s it.
The only other alternative is to open the boiler fill and drain the whole system in order to refill it. This will likely lead new air trapped inside, however, so it’s not a great option. Calling a professional for something like that will likely save you a lot of time and effort.
