cold second floor radiators

John S_2

You might need more than 12 lbs to get water up to the second floor, depending on the height of the rads. The pressure gauge might be off too. Can you post a photo of the feed valve?
I wouldn't try to feed it yourself by hand. Get someone out who knows how to do that kind of thing. You'll end up ruining the relief valve or something.

Kirk Shriver

cold second floor radiators, gravity system

No problems for 12 years. I have learned how to bleed radiators once in a while. This year my second floor radiators where cold so I tried bleeding and it didn't work. There is a compression tank near the boiler so I drained some water out of it (you will try anything if you don't know much). I was told later (by the service man from the oil supplier) that I should have closed the valve to the tank before draining it and that I was just draining the whole system. The guage says that there are about 12 lbs. of pressure in the system so I should be able to bleed my radiators. I keep trying but get just a little air out each time and no water yet. The oil man said that I may have a problem with and need to replace the water feed valve. I have a few questions: Is this enough information for anyone to tell me what is wrong? If there is a problem with the feed valve can I feed it by hand this season so that I don't have to drain down the whole system during the heating season? Should I be bleeding the radiators while the boiler is on or off? Is there any sequence to be followed when bleeding multiple radiators?

Ken_40

The answer is simple.

The circulator is probably backwards and has been since the system was installed.

A hot water heating system is sealed, where and how can air get in? How can a sealed system get air, need to be bled once every year or so?

Simple. The circ. is "sucking" the water through the system, creating a slight or near vacuum! That vacuum allows the air that is supposed to stay "trapped" in the expansion tank to "bleed" into the system by virtue of the vacuum created by a mis-located circ.

The cosntant flow and ebb of on-off cycles over long winters allows water to be "fed," via the pressure reducing vavle and it becomes "plugged up" from the ying/yang forces of on-off operation.

The condition is minimized to a simple nuisance, if the circ. is a "low head" variety, like the venerable B&G S-100.
These days, we tend to install small "wet rotor" circs. and the vacuum issue can exacerbate the condition you are experiencing.

Yes, the pressurereducing valve is probably shot (you could check the inlet screen for junk impaction), but after 10 years of service in a "wrongly directed circ." - may rerquire replaement.

If the guy who showed up did not mention not "pumping away" as a likely cause, you might consider looking at the "Find a Professional" button atop this page. Virtually everyone who is listed knows what "pumping away" means, and can explain it to you in simple terms.

Let us know how you make out.

Lastly, a few digital photos would provide the old, "a picture is worth..."

John S_2

duh?

Did you miss the part where he said it was a gravity system?