CH not HW

[darrylcoalter]

I have central heating but no hot water! The boiler is a Glow Worm Micron and is only a few years old. I have taken the central screw out of the pump and it seems the pump is turning fine (its not loud and doesn't vibrate much but I think it is running ok) It certainly turned when I turned the power back on. The valves to switch to central heating are operating ok. Everything is getting hot except the water in the tank....Is it the pump?

Any help would be great....cheers

 

[ollski]

Is power switching across your cylinder stat?

 

[kevplumb]

is the valve working correctly

 

[darrylcoalter]

I beleive it may be the cylinder thermostat.....when the boiler is running turning it right up or down makes no difference to the operation of the boiler

 

[felix]

You need to start with the boiler and pump off. Turn the CH off at the controller or turn the room stat right down.

Now turn HW on. Does the boiler start? Swing the cylinder stat back and forth. Does the boiler start? Note that if it doesn't start it might not be the stat that's at fault. It could also be the controller or a zone valve. We need to know what valves you've got.

If you can't get the boiler to fire up without a CH demand you'll have to start measuring voltages. If the boiler does start check the pump. You might have gravity HW and the pump only runs for CH. In this case there is often a zone valve in line with the cylinder heating coil. If you can find one check that it's open.

 

[darrylcoalter]

Thanks Felix
It was the stat. All fixed now