Halstead Ace Combi

[hobroydharry]

Can anyone shed light on a niggling snag on a Halstead Ace.

When on hot water the boiler fires up OK and the water gets warm then the boiler cuts out and the water cools till the boiler fires up again and the whole process is repeated, constantly cycling on / off. The boiler has only started doing this recently.

On heating the problem does not exist.

I have changed the filter, checked the heat exchanger is clear (soft water area), checked the 11 milli amps on the thermistors and checked the flow rate is correct as per the advice of Halstead, infact all they suggest has been done.

I am now going down the path of changing the diaphram in the bypass valve before considering replacing the whole bypass valve.

Any ideas greatly appriciated

 

[Deleted member 105431]

classic symtoms of poor heat transfer due to blocked ch side of plate. Did you take a water sample or remove plate and clean under tap?

 

[hobroydharry]

Took off the whole heat exchanger off and cleaned it thoroughly, what a pain!! I am convinced the bypass valve is not moving to its full extent?

 

[Deleted member 105431]

Took off the whole heat exchanger off and cleaned it thoroughly, what a pain!! I am convinced the bypass valve is not moving to its full extent?

the bypass would not cause the symtoms you describe. Check the ch flow pipe temp when you run the hot tap, the diverter valve may not be shutting off the htg fully.