Intesa/Ariston combi boiler dhw problem

[reedjr]

DHW fires up but shuts down within seconds.

Water gets quite (too?) hot but little comes out of tap and formerly cold radiator out pipe gets hot.

Central heating works absolutely fine but occasionally looses a bit of pressure (this may be a small amount of water as the system is very small with only 4 radiators on most of the time).

I have recently descaled kettling exchanger with Sentinel x800.

Assuming that the diverter might be failing/blocked. Has an electronic actuator. What is the best thing to check first?

Any ideas gratefully received.

Actuator on page 41:
http://www.ariston.co.uk/uploads/doc4836d8f6570d6.pdf


Cheers,
Jonathan

 

[EPH]

Blocked plate?

 

[Billy Bob Bob]

call out a experienced gsr engineer there may be many possibilities why dhw is playing up