No heat in radiators

[stevobogger]

We have a Glow worm cebtral heating system in a home we just bought, which is 35 years old. When I had fixed a couple of leaky radiators and bled them to fill the system again I turned the system on for a few hours but nothing heated up. I could hear the boiler start up but obviously somethings up. Any sujestions.

 

[noonespecial]

Is the system open vented or sealed?

Have you checked that the whole system is filled up with water?

Is pump operating?

Is hot water gravity or pumped fed from boiler? Is cylinder heating up.

Is boiler actually firing and heating up the heat exchanger?

 

[chrishutt]

If system has been drained down and idle for some time the most likely fault must be the pump sticking. Can you undo the large screw cap on the head of the pump and free the spindle?