Problem with Radiator

MPL15654

I have a customer who had replaced her boiler a couple years ago, its a Dunkirk PSB-4D. Since it was installed she's had problems with balancing the system. She's had it re-piped a couple times(not by my company), and the steam piping is correct. She has a 1 pipe "Counterflow System". Supposedly she never had these problems with the old boiler. The radiator at the furthest end of the house in not heating up and only heats up if the boiler is running for a long time (thermostat cranked up). I believe the installer added main vents on both drips, i don't believe they were original. It's my feeling that there should be a main line air vent at the end of the main. I think these air vents on venting the air too quick and getting steam to the radiators closest to the boiler, and starving the radiators at the end. I was wondering if i should cap those air vents, put a Vari Vent wide open on the two radiators that are furthest from the boiler and slow the vents down on the radiators closest to the boiler. It really isn't an option to add a main line vent at the end of the main, the piping is covered in Asbestos and the homeowner is running low on funds. Any ideas?

Jamie Hall

Can you get at

the top of the riser to the radiator at the end of the house which doesn't heat up without too much trauma?  If so, there is not particular reason why you couldn't put a "main" vent at the top of that riser -- even a Gorton 1 or 2, depending on how much space you have and how long the main is.



Then you could adjust the radiator vents as you suggest -- only you wouldn't have to open those end ones all the way, perhaps, as it would just be coping with the radiator and not the main and the riser.



Depending on the size of the riser pipe, you might even be able to get away with drilling and tapping it for the vent?  Or something creative of that sort?  Might look a little odd, but...



I would be very wary of a statement like "I never had a problem with it before..."; it's remarkable how often selective memory kicks in on things like that.

Double D

Vents on the drip!?! Useless!!

Yes there should be end of main vents or as Jamie said top of a riser to the radiator at the end of the house. Post pictures of the near boiler piping and the end of the mains if possible.