Radiators at one end of house not heating up
I’m trying to figure out why the radiators at the front of my house stay cold while the ones at the back get quite hot. The radiators at the front do heat up eventually if you crank up the heat to the point where it’s uncomfortably hot in the rest of the house, so it’s not that they are off. We have a 1900 sf. 2-story house with 7 radiators. The problem is especially pronounced on the second floor. The front room up there just doesn’t get any heat. The boiler, a Weil-McLean that’s about 8 years old, is toward the back of the house. I just had a plumber come to do an annual servicing of the boiler and got all new vents, both in the basement and at all the radiators, and got all the radiators balanced/pitched properly. The plumber said maybe the radiators in the front aren’t heating up because the boiler may be under-sized – I don’t know how to tell what size it is, but since the house is really not all that big, I’m a bit skeptical of that explanation. I did notice that the pipe that spans the length of the basement, from front to back, and that all the risers come off of (the steam supply main?), seems to be pitched up from the back of the basement (where the boiler is) toward the middle of the basement and then goes down again after the point that all the risers but the front ones come off of it. Any ideas or suggestions?
backeast
in Plumbing 10 years and 5 months ago
16
182
Please log in, in order to post replies!
16 replies
backeast | 10 years and 5 months ago
Aha. There is a master vent at each end of the main steam supply main, and also another vent that it looks like was added some time ago, about 5-7 feet back from the front end. This one hasn’t been replaced. So, former owners may have had the same issue and resolved it with the extra vent. Maybe I’ll try replacing that one, and insulating the pipes. Or getting a larger main vent in the front and a smaller one in the back. Thanks all.
Hardcharger | 10 years and 5 months ago
Is the front traveling through an exposed cellar? I ordered massive pipe wrapping. This plus adding main vents evened out the front and back in our building.
eman134 | 10 years and 5 months ago
The main vent at the long run should be increased to the point that steam hits the front and rear mains at the same time…the rear should also be choked down by downsizing the vents on the rear of the building…steam heat is like a balloon…if you squeeze it in one spot it will take the path of least resistance and go elsewhere. I disagree with your plumber, since thermostatic vents on a one pipe system will add complexity to what should be an elegantly simple solution
steam_man | 10 years and 5 months ago
The purpose of the main vent we all mentioned first is to get the steam to the furthest end of the main at relatively the same time as the closest end (to the boiler). If your plumber made his suggestion without checking venting then I’d be suspect of thermostatic valves and moving Thermostats and such. Check venting first!
backeast | 10 years and 5 months ago
OP here. Thanks for all the responses! I had the plumber here to look at it and he said the reason the radiators in the back of the house heat up while the ones in the front don’t is that it’s a longer run to the ones at the front of the house, and my thermostat is closer to the back, so sensing the heat from the back radiators and maybe shutting off the boiler before the ones at the front of the house have a chance to heat up. Does this sound right? Just to clarify – if I turn the heat way up at the thermostat, the front radiators do eventually heat up, but by that time the rest of the house is unbearably hot. The plumber recommended thermostatic valves on the radiators at the back of the house to keep those rooms from getting too hot (and maybe give a chance for the radiators at the front of the house to come on). Before I shell out the money for those I’m going to try just turning the radiators at the back of the house off when they are cool so there is no condensate left them, and keeping them off. We’ll see how that goes. But, any feedback on the thermostatic valves? Are they worth it? Master Plvmber, I think the steam supply main goes up a few inches over about 20 feet of length from the point where it comes out of the boiler, and then goes down. Maybe that’s the root of the issue, but the plumber didn’t have any comment on the steam supply main.
whitethomas4 | 10 years and 5 months ago
First lets look at the possible solutions when all of the radiators are not working. Make sure your heating is turned on and that the room thermostat (if there is one) is turned up and calling for heat. If only one radiator is not working, scroll down further for possible solutions.
eman134 | 10 years and 5 months ago
ninzk86 half of steam boiler installations in brooklyn do not even have vents on the mains…you have to hire someone to drill and tap the main and install the appropriate sized vents
eman134 | 10 years and 5 months ago
as steam man said your system pressure should be way below 2 pounds…if you can afford it, replace the crappy little pressuretrol that package boilers usually have with a vaporstat so you can adjust the pressure of the system way more accurately…if you want more info, my contact info is in my profile
steam_man | 10 years and 5 months ago
The main vent is located about 18″ back from the end of the main, on a nipple about 8″ up. Gorton could be good. My personal preference is a Hoffman No.4A. Be aware that this valve isn’t going to work if your steam pressure is above 2#.As for the Gorton, I don’t know where to even find the specs on them. Lastly, make sure you have enough venting capacity for your mains.