Hot water and heating problem

[Rossi90]

Hello,

I have a problem with an old back boiler, the problem is when we turn the hot water on the heating comes on as well even when the heating is set to off. At first we had a problem with the timer not working properly. Because of the age of the boiler I bought a similar timer off eBay. Tried to fit this myself but was unable to do so. Have had an electrician round but he was not to sure about the wiring. I have read on the Internet that It could be a problem with the wiring of the timer or the M.V.

Would appreciate if anyone could point me in the right direction thanks.

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[HERTS P&D]

The problem is the MV.

http://www.ebay.co.uk/itm/Honeywell...arden_Hearing_Cooling_Air&hash=item4ac7af7b1a

Andy

 

[Boilerman2]

That is a very old Honeywell Mid Pos valve !!

 

[Rossi90]

Thanks for your help. So if I was to put the old timer back in and get some one to replace the MV hopefully this will solve the problem. With the age of the boiler are the MV easy to find? The boiler is around 25 years old if not older, had its money's worth out of it.