Alpha CB28

[avidfan]

I have a client with the above boiler who complains that it keeps locking in hot water mode. Boiler resets ok. This is an intermittant (groan) fault and every time I visit it works fine despite my best efforts to make it overheat. Diverter valve was changed a couple of years ago. Am I right in thinking that when the thermistors play up they cause the boiler to cut out rather than overheat? Anybody else had this as an intermittant problem?

 

[nickso]

ive had faulty thermistor, o/h stat and pcb cause nuisance o/h lockouts on these.

take your pick, i usually start at the cheapest part and work my way up

 

[gas4you]

Personally I would change the primary (ch) thermistor first.

I've had very, very little problems with alpha pcb's.

Could also be worth checking the plate HE is clean.

 

[Paul Barker]

g4u is on the money

 

[avidfan]

Thanks for your help, gents.