How to remove the air from your boiler / heater


Hey Dominic. Thanks for the video. I have a few questions.

1. The experts who installed my system didn’t put a shutoff valve on each of the zones. The only valve in the line is the zone valve that receives the signal from the thermostat switch. I assume I need to turn the heat all the way down and then open the boiler drain as you describe in your video.

2. It is about 20 degrees here right now. My water pressure is just under 30 psi. Is this normal? Is this ok? Is it safe?

3. There is a boiler drain at the very bottom. Am I supposed to open that periodically to let debris and contaminants out?




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dhill 2 years 3 Answers 508 views

Answers ( 3 )

  1. The way I was showing you should do the entire system at the same time. It will just take a while, that’s it

  2. Thanks Dominick. The picture you noted shows one Honeywell valve and 4 Taco valves. The newer honeywell valve does have a shutoff and I was able to get the air out of that one. The other four do not. You can see them better in the other pictures. What should I do for those?

  3. It’s really not that easy to see from your pictures if I’m missing something or not. However as long as you have that one valve closed and the other open all that’s going to happen is that all the air/water will be forced to come out, sooner or later.

    When doing it this way, make sure the system is off. This will prevent the zone valves from opening and the boiler turning on while very cold water is entering. Let system cool down before you force cold water just to be safe.

    Open the regulator up for more water will enter the system. But make sure you close it when you close the valve in the picture I marked up.

    And yes, it’s always good to blast the crap out with the boiler drain. But you may not be able to close it back up as junk gets stuck in the valve, so….

    Look for like 20 PSI. That’s what you want. It’s not like 30 is super bad. There is a self-bleeder on the system make sure the small cap on it is loose.

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