CH issue, confused

[tr7v8]

OK have an old Servowarm Elite 50, just underneath it sits a pump. Upstairs is a hot water tank & 3 port valve. As understand it it is pumped CH & semi pumped HW.
Suddenly it has started running the boiler & the rads are getting hot when the thermostat for heating is off. We still have plentiful HW. Is this a dodgy motor on the valve? There is a lever on the pump I assume ths should move when it changes from HW to CH & back again. I'm struggling to reach or see the valve as the cupboards are full of wives shoes.....

As an aside under the new rules can the boiler be changed for a similar more modern & efficient model or does it have to be combi which I understand means I can't run a power shower. Can a new boiler be installed in the loft & what would be the likely cost of an install in Kent?

[Ferg]

tr7v8 said:

...under the new rules can the boiler be changed for a similar more modern & efficient model or does it have to be combi which I understand means I can't run a power shower. Can a new boiler be installed in the loft & what would be the likely cost of an install in Kent?

You must fit a condensing boiler but it doesn't have to be a Combination Boiler.
Fitting boilers in lofts is a bad idea.
Regulations say that you must have a permanent walkway with a hand-rail between the hatch and the boiler and you must also have a proper loft ladder, not steps.
In addition you would need a frost stat to ensure it doesn't freeze AND there are some very specific issues with gas pipes in a roof space. AND you'd have to run a gas pipe up the side of your house.
HTH

PS Yes, it sounds like the motorised valve is FUBAR.

Edited by Ferg on Tuesday 7th April 19:22

[tr7v8]

Many thanks Ferg!

[Simpo Two]

tr7v8 said:

Suddenly it has started running the boiler & the rads are getting hot when the thermostat for heating is off. We still have plentiful HW. Is this a dodgy motor on the valve?

Mine's been doing that for years. If I don't want the heat I just turn off the affected radiators

NB: Question for Ferg - why can't radiators have 1/4 turn valves like modern taps do? It would save much knuckle scraping twice a year.

[Ferg]

Simpo Two said:

NB: Question for Ferg - why can't radiators have 1/4 turn valves like modern taps do? It would save much knuckle scraping twice a year.

QT valves are more difficult to regulate flow to the sort of accuracy required for [i[properly[/i] balancing a system. Also.... if you got the system working properly you wouldn't need to keep turning the radiators on and off.