central heating pump doesnt turn off

[johnnymacc]

Hi guys a bit of help needed not done much with central heating before but been asked to have a look at one,the problem is the central heating pump overrun wont switch off so pump just runs and runs until power is turned off, any ideas appreciated, the plumber was vague too when i spoke to him.
Cheers, John.

 

[diditrain]

wires crossed, connected into permanent live. Does it carry on pumping long after it is no longer calling?
Could be a problem with the PCB i had to replace mine

 

[Megavolt]

Would expect it to be boilers PCB. Unless its been doing it from new then I would look at wiring.

 

[La Poste]

We will be review any matters and always get a perfect ideas and taking action as well as practice and diversification so be conscious and happy life suffer for well ideas.

What??

 

[oldtimer]

We will be review any matters and always get a perfect ideas and taking action as well as practice and diversification so be conscious and happy life suffer for well ideas.

Well there you go but back to the real world it depends on what type of system you have ie if it is a old gravity system then the pump comes on with the boiler me I have 2 control valves 1 for hot water 1 for central heating so when any valve fully opens it switches the boiler and pump on together but thats fine for me some of the newer systems have a PC control card in the boiler and everything is wired back to this.

But the question is w
hat type of system is it ? H
as the pump always ran on ?
How old is the system ?
Did the pump used to switch off before ?
Has the system been adjusted recently ?
Does the pump run on function have a adjustable timer ?

Now it could be that the system has never been wired properly and this fault has always been their or it has just started to work this way so where is the pump wired to ie via a zone valve or straight into the boiler.
Why do we have a pump run on well some systems like mines just switch off and the boiler absorbs the heat other boilers may need a pump run on mode to disapate the heat and this could be via a set timer or on temperature control ie after 10 minutes or after the boiler temp has dropped to ??oC

 

[bathroomrenovat]

It would be wires clash. Hope the fault would be in wiring.

check it