one pipe system with some radiators having two pipes on the first floor

papa12603

The building I have has a store (a restaurant location) and I noticed that 3 radiators have 2 pipes and 2 radiators have just one pipe. They all work though. Is this normal or does it affects the functioning in other areas? I have always have issues in the building with banging, some cold radiators, flooding, etc.

Jamie Hall

There's no good reason why it won't work -- if everything is done right.

The radiators with just one pipe: make sure they are pitched towards the valve, and make sure the valve is fully open. If the valve is open but the radiator doesn't heat, make sure the vent is open (part way up the opposite end from the inlet).

The radiators with two pipes. Can you take a photo of one, or describe further? If they are "real" two pipe radiators, there will be a steam inlet with a valve at one end -- usually at the top, but sometimes at the bottom. There will also be an outlet at the bottom, usually at the other end but sometimes at the same end. That may have a trap on it, and the outlet may be warm, but shouldn't be steam hot. The radiator should be pitched towards the bottom outlet.

OK. Now. If you have banging, it is almost always from water getting trapped in the pipes somewhere. Go through the whole system -- every length of pipe -- and make sure that all of the pipes are pitched so that water can drain back, one way or another, towards the boiler. Level won't do; there has to be a definite pitch.

At the boiler, there will be a pressure control. It should be set so that the boiler cuts out at no more than 1.5 psi -- but without knowing what you have, I can't go farther than that.

Some pictures of the boiler, showing the piping around it, and some pictures of the radiators will help.

Dave in QCA

I am familiar with a large old home nearby that has a combination of 1-pipe and Vented 2-pipe. In this case, the 2-pipe vented rads are on the second and third floor. My assumption is that it was easier to hide the smaller pipes used on the 2-pipe vented rad as they ran to the upper floors inside the walls.

papa12603

Thanks Jamie and Dave. I will take pictures and post them very soon thanks so much.