HWradiator never hot

Old 11-25-04, 08:39 PM
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HWradiator never hot

I have an "always been cold" radiator/room(2nd floor farthest from boiler), supply pipe in basement is hot/return is cold, boiler runs fine, i bled out air, has (luke warm water) pressure at bleed, does it sound blocked? or maybe circulator undersized or tired? its an end of run radiator, so piping is narrowed down to 3/4" in/out from 2-1/2" at start of run. House piping is original (est 50yrs) but boiler system is <10 yr old and in excellent condition. any ideas?

Last edited by Heatmiser; 11-25-04 at 08:43 PM. Reason: info add
Old 11-25-04, 10:55 PM
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Most likely not enough system pressure. What is the pressure at the boiler? Is the boiler in a basement?

You should have 15 to 18 psi to get heat to the second floor. The circulator pump does not know it is pumping uphill, it is just circulating. You need enough boiler pressure to get the water to the second floor.

Please post back with pressure reading, and let us know if you know how to get more pressure to the system if needed.
Old 11-26-04, 08:54 AM
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My gauge was reading 15 psi and i bumped it up to 19, other rads on 2nd floor are always quite hot, yes boiler is in basement. Also rad 1/4 turn valve was almost closed, but now that it is open the rad is only warm. i will try checking system psi at system bleed valve. these old round wooden handled rad valves are best left undisturbed(i just guessed at stem height that it was open). I will give it till tonight to see how rad performs.
Old 11-26-04, 08:49 PM
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If you get water out of the bleeder on the radiator, system pressure is high enough. System pressure keeps the radiators full and the circulator moves water around. I think making sure the valve on the radiator is open is most important. The next best thing you can do is find the radiator closest to the boiler and close its valve at least half way. It won't make that radiator any less warm, but it will remove some of the short circuiting of water that is causing the low flow in the other one. Let us know how things shape up.


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