boiler drain valve leaks and autofeed switches on too early and more!

chuside

Bought a home a couple years ago (built 1950s) and this year a number of issues came up. I am completely new to working on heating systems, so some may suggest I call a plumber. If it comes to that I'm fine with it but I'd like to fix what I can so I can learn.

1.) The boiler drain has slowly increased in it's drip. It used to be occasional and is not constant. Spoke with a plumber who came to replace my hot water heater that broke and he suggested putting a cap on it, but I'm not sure that's really going to change anything and would like to fully solve the issue if possible.
2.) I looked at it again today and saw that sight glass was totally full so the autofeed overfilled it. When I first bought it, I did manually press the autofeed a few times, not knowing what I was really doing, so I'm not sure if that's what the situation is. I've drained it below the line and am waiting to see if it overfills again.
3.) This may be related to #2, but one of the rooms in my house pushed out lots of steam in the winter. It's spring now, so I don't think I'll experience it again, but would too much water in the system cause this to happen?





Thanks in advanced.

Jamie Hall

You have two choices on the drain -- replace the valve, which requires draining the boiler but is much the better choice, or putting a cap on it as the plumber suggested. The latter will work, but is rather a kludge.

On the fill -- the water should be half to three quarters of the way up the sight glass, and should be pretty stable when the system is running.

On the radiator -- was it steam that came out? If so, an overfill could be the problem -- but it could also be either a bad vent or too high a boiler pressure. If it was water, it could be an overfill, but it could also be a problem in the piping, trapping water.

Make sure that the valve to that radiator is fully open. That can trap water, too. And then make sure the pressure is set correctly -- the boiler should be set to shut off at no more than 1.5 psi.

chuside

Thanks @Jamie Hall I recently drained a good amount of water and the drip stopped. but then in an attempt to get it back up to the previous owner's marking on the sight glass, it started dripping again. I'm going to try to drain it again and see if it stops else I'll replace the valve. Any tips for this task, should I need to go that route?

The radiator had heavy steam coming out to the point where it was spewing water at the vent, but the room felt very damp after the heat was going. I'm hoping draining the overfill will fix this.

I appreciate the help.

newagedawn

i agree cap the leaking drain, unless you really feel like changing it, on a steam system it easy, just drain water and change valve, i would recommend one with a ball valve shut of it will last a longer time than the other you had, the rest? the auto feed could be adjusted to come on at a certain time but youd have to watch the cycle to get this right, then adjust the dip switches accordingly

Jamie Hall

That radiator vent is toast. You need a nice new one. The trick is to find one the right size, so that the radiator heats the room properly -- there are variable vents so you can fiddle. Don't skimp on the vent; spend the money for a good one.

STEVEusaPA

Are you sure it's the drain and not the PRV (too)? Dropping pressure and the drip stops tend to lead more towards the PRV. They could both be dripping.

chuside

Thanks for the comments.

@newagedawn I bought a ball valve and will hopefully replace it this week. It seemed simple enough like you said and I'm eager to learn.

@STEVEusaPA I'm pretty sure it's not the PRV as only the drain valve drips. Is there something I'm missing?

@Jamie Hall I'll swap out the radiator vent too. I had a brand new varivalve installed on it not too long ago. The plumber I hired made it seem like a good option. Is that not true? Suggestions for good vents?

Jamie Hall

Varivalves are perfectly good, and usually quite reliable. Hard to say on that one. Check your pressure?

Big Ed_4

I feel Varivalves vent is too fast for an residential home . They could throw out the balance of of heat in the home .. Yes they have their place on an problem vented radiator ..They really were made for buildings using the Heat Timer control .. They also have no float like an Hoffman or Gordon vent .. I prefer to see an float just incase the system is over filled ...

All boilers where designed to be 1/3 water level .. Why heat up that much more water to make it boil .. There is so little you can do to make a steam systems more efficient ..

That style boiler drained was once common ..... they always sucked .. Sometimes when you cap them and they leak off the top . It's not really an packing , just an rubber washer under that nut .. I always cringe when I have to use one .. And replace them when I can...