I have two radiators upstairs on the second floor (top floor) that are cold. When I bled them a few days ago, all of them released water. They are still cold. I need those radiators to release heat as it makes the floor very cold. I don't know what to do. Even though the boiler is very old it is currently at 2.0 bar when working.

How can I get heat flowing from these radiators?

  • Are there any valves to these radiators that may have been turned off, preventing flow? Are there any pumps that may have failed?
    – FreeMan
    Jan 15 at 15:20
  • Have you ever had heat coming from these radiators?
    – FreeMan
    Jan 15 at 18:01
  • Both valves to these radiators are open. Yes, up until last year, heat was coming out from these radiators.
    – Raphael
    Jan 18 at 19:54

1 Answer 1


You can get water releasing from the radiator and still have air trapped somewhere else in the line, so the heated water from the boiler never reaches them.

First, check to see if the water you are bleeding from the radiator is cold or hot. If cold, then hot water isn't reaching the radiator. If hot, then the boiler and piping is fine, the problem is in the radiators.

Assuming the bleed water is cold:

  1. if those upper floor radiators are on a separate heating zone, check the pipes for that zone just above the boiler and see if they are hot. They should be.
  2. most boilers have a way to bleed water from the zone piping at the boiler where the piping leaves the boiler. Usually there are two valves. One of them allows the pipe to be turned off so no water goes in from the boiler, and the other is similar to an outside faucet that takes a garden hose end. Attach a hose and run it into either a 5 gallon bucket or outside. Turn off the valve on the boiler side. Then open the valve to allow water to drain from the pipes into the bucket. Be careful, it will be hot and under some pressure. Depending on the size of your house, it might take ~10 gallons or more. Generally if there is an air pocket you'll actually hear the water spurt and gurgle. Once the water runs evenly, close that valve and reopen the access valve to the boiler.
  • Thank you for the tip. I will check that.
    – Raphael
    Jan 18 at 19:52
  • @Raphael please take the tour to see the proper way to say "thanks". (hint: click the up arrow next to the answer)
    – FreeMan
    Jan 19 at 12:15

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