Boiler not firing. Pump constant run.

[Money4nowt]

Right, I turned my heating on and realised that my downstairs radiators were ice cold but my upstairs ones were red hot. I checked my pump in the cylinder cupboard (danfoss pump) to see if it was spinning by removing the large screw cover to see the impeller spinning. It was running fine. I turned the room stat down whilst I fiddled with a few locksheild valves to see if I could force water through the downstairs rads. When I turned the room stat back up the fan was running on the boiler but it wouldn't fire. This happened a couple of times. I noticed that the over heat switch was in the "out" position so I pushed it back in. ( the boiler is a glow worm ultimate, unsure how old) the boiler fired up temporarily but not for long. Now the fan doesn't run or boiler fire when the room stat is turned up or when I open a hot tap. I have two motorised valves in the ac cupboard if that helps. The pump is now constantly running and only stops when i switch off the power. What could be wrong??? Thanks.

 

[Murf520970]

edit

 

[Money4nowt]

Thanks for the reply. Do u know what might be the cause of my problems??

 

[Money4nowt]

A quick update of what happened this morning.
I had switched the power off in the cylinder cupboard over nite as the pump was constantly running. When I turned it on this morning at first the pump didn't run. Then a zone valve open the pump started running and the boiler fired up as normal. This only lasted for about a minute before the boiler has now shut down ageing and the pump is running again??

 

[Murf520970]

When i first read this i was inclined to think you had a faulty zone valve not opening & closing properly , but its odd that the pump is running all the time but the boilers not firing so you may have a boiler fault as well ,get someone out to have a look at it & save yourself the grief

 

[Armo74]

Maybe a faulty microswitch? Or a wiring issue? but it's guess work really unless it is an obvious fault it has to be a process of elimination.

 

[Money4nowt]

Thanks for the replys guys. Think I'm gonna have to bite the bullet and pay someone to have a look. Don't like parting with my hard earned. Am a carpenter by trade and work as a site manager so am quite handy with most things and have a bit of knowledge. Oh well.

 

[picasso]

If the pump continues to run the pcb is faulty.

 

[gas_man_gaz]

id guess a blocked cold feed, sounds like ya pump is running but the water isn't circulating correctly.

 

[Money4nowt]

Hi all. Quick update. I got up in the loft and my small tank was bone dry. It looks like the cold feed to the tank was turned off because of a dodgy ballcock, it doesn't close fully so over fills. I filled the tank and turned the switch on in the ac again. Boiler fires again and works fine. I thin everything is ok.
Thanks for your help guys.

 

[picasso]

id guess a blocked cold feed, sounds like ya pump is running but the water isn't circulating correctly.

Good guess !

 

[Agile]

If the pump continues to run the pcb is faulty.

Bad guess ?

 

[picasso]

sarky twa@t ?