Ideal classic nf40 boiler, no hot water

[Mark Saunders]

Hi,
We have a rather old ideal classic nf40 boiler. Which has been working just fine.
The other day the missus son accidentally switched the power supply off (for a few hours)
Since then the heating still works fine (on the timer and when advanced) But the hot water is no longer working. It tries to "fire up" but doesn't.
Regardless of whether it's advanced or on the timer, it's still won't kick in. It makes the noise of trying to start but cuts out straight away.
Ive turned all the timer settings off and tried it again, and reset all the timings........ Still nothing.
It's been fine until the power being switched off.
Any ideas or is it engineer time?

Many thanks

 

[lightning]

Faulty 2 port or 3 port valve or faulty cylinder stat

 

[Mark Saunders]

Can these be tested or is it a case of trial an error...?

 

[lightning]

Yes can be tested

 

[Mark Saunders]

Ok thanks, I'll see about getting a plumber / heating specialist to have a look....
Thanks again