Boiler Thermostat

[Bracken99]

I have a Worcester Greenstar Heatslave External Boiler model 18/25 and the heating is being temperamental. It doesn’t always come in.

As hot water has precedence, what I have done previously is run the hot water until the boiler fires up and then when the HW was at temperature the diverter valve would switch to CH. this isn’t happening now.

The house thermostat is a Digistat +3RF wireless. What occurred to me was that perhaps there is a thermostat within the boiler that is telling the boiler that the CH is up to temperature and therefore ignoring the request for heat from the Digistat?

Does anybody know if this could be the case?

Thank you.

 

[cross thread]

You could try bringing the receiver out ,to see if it’s a control problem..Power off first !

 

[Exedon]

Have you a multimeter and are competent to use it?
Dependent on where controls are you can have 3 live feeds into that boiler.
My first suspect would be diverter valve.

 

[CountryFan]

Have you tried new batteries (good quality ones) in the thermostat?

 

[Bracken99]

Thank you all for your considered responses. I have just had an engineer out and naturally the boiler was operating without a problem!

However I explained the symptoms to him and it is his belief that the issue is with the diverter valve. I am not totally convinced but will keep an eye on it.

Thanks again.

 

[Exedon]

However I explained the symptoms to him and it is his belief that the issue is with the diverter valve. I am not totally convinced.

You should trust your engineer we look after a fair few Worcester oil combi's what you described is typical diverter valve problems.
There are other possibilities but depends on model boiler you have Worcester have made a few.