Main valve

cossy

One of my main valves is releasing steam. Could that be from too much pressure or do I just have a faulty valve I need to replace?

Fred

That's a Vent, not a valve. Make sure the pressuretrol is set for .5 PSI Cut-in (scale on the front of the Pressuretrol and the white dial on the inside of the Pressuretrol is set to "1" facing the front. In all probability that vent is bad and needs to be replaced. It is probably way to small for your Main. How long is that main and what diameter pipe? If you have more than one Main, measure the others to and we can tell you what vents to use. Good venting on the mains will reduce fuel consumption, reduce system pressure and get steam to the radiators quicker.

furnacefigher15

If its leaking steam, its either bad or the system is at a higher pressure then its rated for.

Its most likely bad. Ditto everything Fred said.

cossy

Thanks for the quick response. Its 2" pipe and it runs about 25' into a crawl space. I have another main thats the same diameter and runs only about half the distance. One of the radiators the main supplies was leaking water, but I increased the pitch and turned down the radiator vent and that seems to have stopped the leaking. This radiator was on the main with the leaking main vent.

The system just cycled through. The main vent that was leaking never expelled any steam nor even got hot. The radiator on the 2nd floor that was leaking didn't get hot either, which is fine. That room is a guest room and gets way too hot anyway.

Could the main vent have been leaking because of the water in the radiator?

cossy

Also, the pressuretrol was set for .5/1 before the vent was leaking.

Abracadabra

The vent you have in your picture does not provide sufficient venting for your main.

cossy

Thanks, Abra. What size do I have and what size do I need?

Fred

I would suggest you use one Barnes and Jones Vari Vent on each Main. They can be adjusted so that steam gets to the end of each main at about the same time, even though one is shorter. See link:
https://www.amazon.com/Barnes-Jones-BJ-2VV-NPT-Vari-Vent/dp/B01GQP0DQ8/ref=sr_1_1?ie=UTF8&qid=1482532420&sr=8-1&keywords=barnes+and+jones+varivent

Sailah

I have more of those at factory if needed, just call