The boiler is on; the pipe near the boiler is hot, but the pipes furthest away are cold. What does that mean, and how can I fix it?


There could be air trapped in your system - that is if the pump is working. You might have to bleed the system at the burner and/or at the radiotors.

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And a good flush could help, but you might need help with that.

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  • A : Bleeding valve
  • B : Trapped Air
  • E : Reducer boiler performance

There are different water heating systems, but I'd check if the the pump that is pushing hot water through the pipes is working.

A circulating pump in a central heating system typically looks like this.

enter image description here

You can tell if your pump is working by:

  • Checking if the pipe is cold or hot each side of the pump. If it gets cold a foot or two after the pump, it is not working.
  • Checking if it hums or vibrates when the heating is on.
  • You should hear the water flow through the pipes when it's on.
  • Sorry for the short answer, I edited it.
    – Danny T.
    Jan 6 '12 at 15:49

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