Need help with this one.

mattysofia

Ok so I have a hydronic burnham gas boiler radiant heat. With 12 zones. The problem I have is this. One of the pumps was not working so I changed it so while the water was drained I changed out the expansion tank #60. I also changed the water feed valve. And this is when the problem started. The low water yellow light would come on and shut of the boiler. I had no idea what it was so I changed out the low water controller as well. So it worked fine for 2 days and then again yellow light was on and boiler not running. So I released relief valve and boiler kicked on. Pressure at the time when boiler was not working was 20 . But boiler heat was 40 degrees. My question is why does the boiler come on every time I relieve pressure from the valve. Can this a faulty transformer or faulty relief valve. I also changed out a high vent as well. Any ideas would be greatly appreciated. Thank you

Zman

It sounds like the boiler is air locked. The low water cutoff is doing it's job and turning off the boiler when air is detected. When you burb the relief valve the water takes the place of the air and the boiler fires.

mattysofia

Ok thanks. How can I fix air locked boiler? I purged all the zones. Should I change air vents for all the zones?

mattysofia

Should I attach a hose to bottom of the boiler and run it for about a minute with the water on?

EBEBRATT-Ed

@mattysofia

You have changed a lot of parts and spent $$$.

You need to get all valves on n the system open and with the pumps off bleed at the high points. Maintain the water pressure in the boiler at 12 psi minimum while bleeding

mattysofia

Ty so much I really appreciate all your help

mattysofia

Thank you zman. Thank you ebebratt.