Why isn't water coming out of a radiator in my freshly pressurized system?

Question

I live in an old Victorian with three stories, plus a basement and an attic. I tried to bleed the radiators in preparation for turning the heat on, but was unable to get any water out of the radiators on the third floor. I raised the water pressure on the boiler, which is in the basement, to 22 psi and got a ton of air and (very dirty) water out of eight of the ten radiators on the third floor.

The other two, however, did not release any water OR air. ??? Other internet forums suggest that they might have blocked valves? Something about sludge? I don't know what that means or how to fix it, and all the information I found was about radiator systems in Europe, and I suspect they might be different.

I came across weird things on two other radiators, too. One on the first floor spurted water out of the bleed valve as well as the spout it's supposed to come out of. The resident of that room reported the radiator was cold all last winter, but I got water out of it right away.

One on the second floor doesn't appear to have a bleed valve at all? There's a metal thing sticking out where the bleed valve should be, and it looks sort of like a longer version of the piece that actually gets loosened and tightened in the valves on the other radiators. I couldn't budge it, however, with a key or a pliers.

Any ideas on what could be wrong with these four radiators? How can I diagnose and fix the problems?

Answer 1

I think you have a air lock.

Turn off all but one of the none working radiators, this will force the water to go do that radiator. Then bleed the radiator and move onto the next one. Do with with the pump running, but the boilder turned off (or turned down so it does not heat the water).

If that does not work, you will need to get someone in to flush the system. Don't overlook the option of just replacing all the pipework and radiators if you have a lot of sludge adn the system is old - then you will only have one trades person that is responible for all problems.