Mexico CF455 cutting out

[stuhall1973]

Hi,

Mexico CF455 boiler:

Just moved into a new house (not new build) and the heating system worked along with the hot water for a short while. Now i'm finding that the boiler cuts out after 1 minute on the hot water setting, and after 5 minutes on central heating setting. I have bled all the radiators and am getting no air out of them at all, but i've noticed recently that 2 were starting to get cold before this happened.

Anyone know if this is something i can do as i am capable(ish) of looking for faults. Also the pump only kicks in on central heating and not on hot water, is this correct?

I've checked all the header tanks and they are both full and the hot water is running freely, so i'm a little stumped.

Any thoughts?

 

[45yearsagasman]

What's in your airing cupboard? You may have a gravity how system which would explain the pump only working on ch. Does water come out of the rads when you bleed them? So many questions!!

 

[stuhall1973]

Hi.

It's an open vented system with a cylinder, expansion tank for heating and a cold water tank. All the tanks are full of water, all the radiators are full of water but the boiler cuts out on hot water stting after 1 minute, and heating after 5 minutes.

really appreciate any help.

 

[45yearsagasman]

Drain some water off the system via a drain cock with hose attached and see if the water level in the small expansion tank drops. This will check for a clear, or blocked cold feed connection.

 

[45yearsagasman]

This could take some time judging by the slow start.
Should all be sorted by next Winter