Trianco boiler and Megaflo unvented tank circ pump problem

[madtrakz]

I have just started having a problem with my heating/hot water system. The circulation pump in the airing cubard has started to run all the time no matter what I do with the thermostat or control panel. Only thing that shuts it down is to switch off the main switch next to the boiler in the garage. The system is fitted with a froststat but thought that it would be firing up the boiler aswell as the pump if it was faulty just like it has done in the past on cold nights. Any info to get me started in the right direction will be well received.

 

[oilman]

Boiler could be feeding a gravity circuit for hot water, and the pump supplies only the central heating. You possibly have a motorised valve for pump control, and it has failed. Other than that the thermostat or control panel could be faulty.

 

[madtrakz]

How do you test the motorised valve, I think there are two in the airing cupboard. Can I manually turn them off?

 

[Boilerman2]

ONLY CARRYU THIS OUT IF YOU ARE REASONABLY COMPETENT IN ELECTRICAL MATTERS!

Turn off Programmer HW & CH, Switch off at main spur,

locate junction box where Motorised valves are wired to.

Remove orange Wire from one motorised valve at a time (they should both go to the same terminal) whichever one allows the pump etc to run when connected is faulty - are they Danfoss by any chance?

 

[madtrakz]

Yes one is a danfoss and the other is a honeywell.

 

[picasso]

what model trianco is it ?

 

[madtrakz]

Its a Eurostar. And I have just carried out the above test and it is the Danfoss valve at fault. Are they common to be faulty? If so what would be the best make to replace it with?

 

[madtrakz]

Took the danfoss valve apart (electrical part) and cleaned out dust with hoover and sprayed with WD40 and system now working A OK. Thanks for your help saved me a few quid no dout.