Central heating problem

[SimpleSimon]

Seen this somewhere before.
Guy calls me to say in the last 3 weeks his street has had a few power cuts. Since then his central heating system which controls both the boiler and the hot water has had the following problem.

He can turn both heating and hot water on separately. But when he goes to turn on both together, the heating cuts out. The heating won't work with the water on.

The guy has changed the programmer, the valve but still the same problem.

Now I think it's either one of two
1. Loose switch live somewhere.
2. Contactors sticking together? (but not familiar with this component so could be wrong.)

Any thoughts gents?

 

[DurhamSparky]

no offence to you but suggest getting a heating engineer...! i would

 

[sparx24]

Heating engineer? thats a plumber who does know how to fit a plug!
The systems are all quite easy to follow, if a Y plan type the fault could be the tank stat wiring or even programmer not tight on back plate, these freq. occur.
Down loads of most circuits available on several forums,
Try googling central heating circuits.

 

[SimpleSimon]

I've got these plans thanks. Thought it was something loose somewhere. Thanks.

 

[rayclubbe]

diverter valve. usually motor. sometimes microswitch faulty then just change the head