Upstairs radiators are barely working

jlc102482October 29, 2012

I am hoping that some fellow old house owners here have radiator experience and may be able to help me out. The problem is that my upstairs radiators are barely working. When I bled my radiators last week, the upstairs radiators only bled air and not water. Thinking I perhaps didn't get all the trapped air out the first time, I tried to bleed them again yesterday and got more air and a little water out of all but the last radiator I tried to bleed.

The downstairs radiators are working just fine, and the pressure gauge on our boiler indicates it's at the optimum PSI (according to the info label on said boiler.) When we crank the thermostat up above 70, the upstairs radiators do get warm, though they're not as hot as the downstairs radiators.

I am guessing this might be a pump problem, since the downstairs radiators are full of water and the upstairs ones evidently are not. Does anyone have any ideas or insight on this problem before I call an expert in?

Thank you for reporting this comment. Undo

Check for a shutoff valve between floors.

And check for a corroded return line or valve that's not letting water circulate

    Bookmark   October 29, 2012 at 10:57AM
Thank you for reporting this comment. Undo

lazygardens - Would the potentially rusty/corroded valves be located at the base of the radiator, or are you referring to something that would be in the basement attached to the boiler or water tank? Thank you!

    Bookmark   October 29, 2012 at 11:12AM
Thank you for reporting this comment. Undo

Every time you bleed the radiators new water with dissolved air enters the system.

Bleeding needs to be done repeatedly.

You also need to know how high the highest radiator is above the pressure gauge.

Multi-story houses can require higher pressure to fill the top radiators.

15 PSI only holds up 34.6 feet of water.

Drove my dad nuts in a 3.5 story house for years.

    Bookmark   October 29, 2012 at 11:15AM
Thank you for reporting this comment. Undo

You must keep bleeding them until you get steady water discharging for several seconds. Then if you still don't have heat, check the circulator pump(s) (if any). Then I would move on to such things as the auto-fill valve or have the pipes checked for blockages. Which may get expensive.
But start by paying closer attention to bleeding out the air thoroughly.

    Bookmark   October 29, 2012 at 1:30PM
Thank you for reporting this comment. Undo

I suspect Brickeyee is right. If the top of the highest radiator is higher than 20 ft above the boiler, the pressure probably needs to be raised above the optimum pressure. But have a plumber show you how to do it the first just to be sure you're doing it properly, then you can do it whenever it is necessary. I have to do it every year.

    Bookmark   October 29, 2012 at 3:34PM
Thank you for reporting this comment. Undo
Circus Peanut

Jlc, there are some real experts on old radiators at the Heating Help forum who might be able to advise, and they also offer maintenance-oriented books & manuals that have helped me a lot:

Here is a link that might be useful: Heating Help Forum

    Bookmark   November 6, 2012 at 10:33AM
Sign Up to comment
More Discussions
White Cedar Shingles: Best price?
Hi all, My wife and I are gearing up to restore the...
Stripper for stripper-resistant paint?
I'm having a tough time removing multiple layers of...
Color advice for new front door
I am buying a new front door (textured steel) to replace...
Strip flooring with unusual cross section
(Cross posted from Flooring forum) I'm renovating a...
Hi. I have never posted in this particular forum before,...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™