Electric central heating problems - ongoing

[HLH]

Can anybody help please?  We have been having problems with the electric central heating in a holiday cottage for about 3 weeks.  The hot water works but the heating doesn't, although the boiler appears to be running.   The radiators will then start to get hot at random times.  We have checked the timer settings.  We have had both electricians and heating engineers go in and each time they leave saying everything is working, but then it fails again within hours.  We have had a new programmer and room stat but this didn't solve the problem.  We then had a new mid position valve fitted.  This seemed to have done the trick for about 36 hours - then the hot water failed!  The electrician went back in and re-wired the new mid position valve and left everything working ok again - then the heating failed to come on this morning (it came on at midday, randomly).  It seems that we can have either heating or hot water but not both.  The bill is now up to £500 and we still don't have a heating system that works.  the boiler is a heatrae sadia and the programmer is Honeywell.  Has anybody come across anything like this before please?  Many thanks

 

[ProDave]

I am sad to say you have had incompetent tradesmen.

I would not leave a customer with a big bill and a non working system.

Clearly something is still wrong so get them back again and make it clear you have paid them enough and just want them to fix, what they said thay had already fixed, for no extra charge.

Without being there I doubt anyone will be able to diagnose what's wrong remotely.

You say they changed the3 port valve. Was that the whole thing including the valve body (the bit with the pipes) which would have required the system draining then re filling? Or did they just change the actuator head?

If ther latter, them my guess would be the valve body is sticking.

 

[HLH]

Thank you for the quick response.  To be fair to the tradesmen, we were given the bill last weekend when it appeared to be working ok following the new valve being fitted. They haven't just abandoned us and aren't pushing for payment.

We don't actually live near the cottage, which makes it more difficult, so I'm not sure whether they fitted a new valve body but I will try and find this out - thank you so much for the suggestion