Heating system kettleing over

[JohnD]

the boiler thermostat should prevent the feed from the boiler being so hot

the cylinder thermostat should prevent the cylinder getting too hot.

if as you describe the cylinder is "boiling" then they must both have failed.


Please look in the F&E and turn the pump speed down and report back.

 

[flinty]

will do..

thanks

 

[flinty]

Ok have tried a few things.

When you have the thermostat calling for the central heating on it's fine.
If you turn the water cylinder temp down , then no problem that thermostat seems to be working ok.

If however you turn the central heating thermostat down so the radiators are not being heated but the hot water is still required then water starts to be blown out of the hot water vent pipe and into the F&E tank.

Sounds like the heating coil in the hot water cylinder may have a hole in it to me and that the central heating is pumping water into the hot water cylinder causing the kettling effect.

Does that seem the most likely thing?

 

[JohnD]

Questions:
What happened when you turned the pump speed down?

Did you look in the F&E like I asked? What did you see?

How much sediment do you see in the water and the F&E, and what colour is it?

Have you got a strong magnet? (if not, go and buy one)

p.s. what you are describing is not called "kettling" but "pumping over"