Hot water vent (!!) on steam main

steamismyfriend

Last year I was tricked by a knucklehead and had a bunch of things done to my system that made it worse. I knew/know enough to quickly stop the “repairs” but have now been unraveling them for the past year and a half.

After a few weeks of just bonkers behavior from the boiler and the radiators I asked my new steam person to change the main vent. We could see that it was new and never assumed anything was wrong with it. Once we climbed up to take it down we discovered that I’ve had a #79 (hot water) instead of a #75 all this time. I feel dumb that I never thought to climb up and check but I knew they replaced the main last year and from the ground it looked “good” to me. 

This is one of MANY variables we’ve been dealing with but what would the effects of having a hot water vent on a steam main be? 

EBEBRATT-Ed

It just won't work righ. It won't hurt anything except it will cause the system to not work as well as it should. Post some pictures of the system, a couple of radiators and a few boiler pictures including the boiler piping.

steamismyfriend

Gotcha, I think I’m asking about what specifically would not work right if a system was vented with the wrong part? Could it create wet steam, for example? Could it interfere with condensation return? Could it cause the water level to surge when the boiler is running?

*not ignoring your request for pictures, just choosing not to for privacy purposes 

Waher

The wrong air vent will either prevent air from escaping the system impeding the flow of steam leading to longer heating cycles to satisfy the thermostat in addition to building pressure which may be sufficient to trip the pressuretrol leading to short cycling of the boiler. If the pressuretrol doesn't work due to a clogged siphon loop (pigtail) or is set to too high of a cut-out pressure the built up pressure may damage the air vents on the radiators. Higher pressures lead to wet steam from the density of the steam being forced out of the boiler which may cause the water line in the boiler to drop lower than usual.

If the air vent leaks there will be a drop in the water level in the boiler over time which can lead to various problems; most commonly excessive make up water being added.

The better your main air vents are the more efficiently and quietly the system will run. Steam needs air out of the way in the pipes to get to where it wants to go and good vents will also keep steam trapped in the pipes so that you don't lose water.

ethicalpaul

Higher pressures lead to wet steam from the density of the steam being forced out of the boiler which may cause the water line in the boiler to drop lower than usual.

This isn't true, but I liked the rest of your response

Maybe the OP can blur out the offending vent so that it won't be identifiable and will be able to stay private!

Steamhead

Not the first time I've seen this. We had one a couple weeks ago. At least the #79 looks like a #75, unlike this:

https://forum.heatinghelp.com/discussion/160298/todays-kodak-moment-uhhhh-beavis-will-these-vents-work