Hlastead Finest Gold Hot Water Problem

[meatballs]

Hi

I have a problem with my Halstead Finest Gold boiler.

The CH works fine although at the moment it is turned off (summer)

The Hot Water when demanded gets hot but then the saftey lockout LED comes on and obviously the water temp reduces back to cold.

I have tried reducing the temperature on the DOMESTIC HOT WATER
CONTROL switch right to minimum. (which worked for a while but now does not)

The overheat thermostat reset button on the underside left of the boiler does not click out so i am assuming it is not that ??.

The fan and pump are running as i can hear them when i switch the mains electric on and off to reset after lockout.

HELP
anyone got any idea??

 

[LUNAT]

HI

could be
1.hot water sensor fault
2.secondary heat ex blocked

 

[meatballs]

Thanks for your reply

by that do you mean the overheat thermostat

or the dhw thermistor?

 

[Gasguru]

Call in a boiler engineer since it involves gas safety parts...normally just involves a simple venturi clean.

 

[ChrisR]

Does it EVER go straight to lockout within a few seconds of switching mains on?

With the HW running, do the CH pipes get hot at all?
I've seen the diverter valve O rings at about 5mm fat instead of the original 1 - 1.5mm, which clogs the whole thing up .

These chaps tend to need a deep service now, a bit like a car's 60,000 miler!

 

[meatballs]

Thank you for all your comments

However after doing some more research i checked the venturi over the fan
which i believe fluffs up and is a common problem on this boiler.

It did in fact have salt crystals in it which i then cleaned off! i think this was probably affecting the air pressure to the APS. Therefore not allowing it to fire up.

After reinstalling venturi hey presto hot water!