main vent not closing

tony_19 · February 4

I just had a leaking buried return replaced and after firing up the boiler the main vent would not close did not have a problem before any ideas why

thank you

ethicalpaul · February 4

What is the water level in the gauge glass doing while the boiler is boiling?

tony_19 · February 4

i believe its pretty steady i will have to look at it again

ethicalpaul · February 4

Yeah look again because the new piping could have introduced oil into your boiler and it doesn't take much to generate significant carryover (large quantities of water thrown up from the boiler into the main) which could interfere with the closing of your main vent.

It can take some time for the oil to make its way to the boiler, but once it's there, it stays there (unless it is then spread throughout your main by carryover)

Or it could be a coincidence

leaking · February 4

defective vent made in China .

tony_19 · February 4

i forgot to mention the vent in the rear of the house has no problem its the one in the front and its a gorton no. 2 the one in the back is maid o mist

ethicalpaul · February 4

OK well if the water level is steady buy a new vent from supplyhouse.com

I find Maid O Mist to be roughly equivalent to Gorton for a lot less money but I've had both kinds fail. Try a Gorton #1 it will be a direct replacement.

All vents fail

4GenPlumber · February 5

I assume you had cement opened to access the leaking return. Cement dust can ruin just about anything that has moving parts. If the vent was near the work, and the dust was dense, and the vent was open (which it was), than it got in.