Bringing a 2-pipe pumped-return steam heating system back in service

PEvans

Right now for the most part the boiler is only maintaining pressure. Usually the zone valves are closed.

So in that state I have a suspicion that the steam trap on the steam header drip is leaking steam into the lower pressure condensate receiver. There is a hissing sound on both sides. I'm not sure how else to evaluate it.

The system is going through feedwater; I have to fill it every day. So I think steam is still getting in the condensate. It is not live steam blasting out the vent.

Jamie Hall

That type of pressuretrol usually is very reliable and very precise -- meaning that it will trip at the same pressure pretty much every time. What it may not be is accurate -- meaning that the pressure at which it trips isn't the same as that shown on the setting scale.

This isn't really a problem, although it's a bit of a nuisance, and the reason is that its very very sensitive to being off level. The best solution is to add a 0 to 3 or 0 to 5 psi gauge on the same pigtail (you do need to keep that 0 to 30 gauge, if that's the only 0 to 30 gauge you have) and use that to determine just where it does trip and adjust it to suit.

PEvans

Yeah, I have the low pressure gauge on the new pigtail with the pressuretrol. I mounted the pressuretrol perpendicular to the loop in the pigtail, and I leveled it. It is hard to read the settings on the pressuretrol itself anyway.

PEvans

I replaced the trap internals on one non-working radiator and it works now. So I believe all of the steam supply mains are working -- that is, they all have some working radiators. I am having a hard time getting the other radiator trap caps off tho.

Jamie Hall

PEvans said:

I replaced the trap internals on one non-working radiator and it works now. So I believe all of the steam supply mains are working -- that is, they all have some working radiators. I am having a hard time getting the other radiator trap caps off tho.

If they have a hex -- most do -- find a six point socket to fit and use that. If you haven't already thought of that...

PEvans

I got a set of 3/4 inch drive six point sockets and I have a 1/2 inch drive breaker bar. One cap came off pretty easily; the others I have tried did not budge. My sockets are deep-ish and shallow would have been a little better.

FWIW given a full set of metric and SAE sockets the one that fits 17C caps is 1 3/8. Maybe that will save some future searcher some money.