Central Heating Pump Runs Continuously

JB1

Joined
23 Jan 2010
Messages
4
Reaction score
0
Location
Northamptonshire
Country
United Kingdom
Hi, Any ideas please. My central heating has been running fine up to about a week and half ago when the cold the cold weather hit. Now the CH pump will not shut down it runs 24x7 whether the heating is on or off. I've tried changing the frost stat ( The boiler is in the garage) the pump overrun stat on the boiler and the overheat stat on the boiler and the thing keeps on running. Any ideas?
The pump is a grundfoss and the boiler is a Potterton Netaheat Profile 80e.

The CH and HW are working fine and the boiler works fine when the timer kicks in.

Help!!!
 
Sponsored Links
Yep I thought that might be the case. But when I turn off the CH and the HW independantly. They both activate.
 
Sponsored Links
Does the boiler boiler fire up as well every so often if so its microswitch in motorised valve.
If it doesnt it will be the pump over run stat in boiler at fault
 
micro switch in the mv is stuck on
you may be able to free it or replace head
 
Ok so which one or both MV's do I change. The system has 2 x 2port MV's fitted. I've had a play this morning and they seem to be working ok but the HW MV was sticky. Pump is still running with the system off. Also the boiler does cut in intermittantly when the HW and CH is turned off on the timer.
 
check the wiring to see which one or maybe both will feed the boiler then disconect and test with a multimeter to see which valve is supplying 240v to the boiler when it shouldnt be.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top