Central heating pump permanently on !

[swayzak]

hi

I moved into a new house a couple of weeks ago (built 1965).

It has a Potterton Suprima 50L, installed in the attic in 2004 by BG.

I immediately noticed a continuous noise coming from the attic at night.

The heating seemed to work OK - but then one morning it didn't start.

Called a local reputable plumber out - we confirmed the pump was receiving a continous signal to run from the boiler. The boiler was reset and has been OK for a couple of days.

He then told me of the infamous PCB problem & advised I call Potterton. Fortunately my serial number is covered by the replacement program and an engineer is coming tomorrow to check the boiler & replace PCB if necessary.

I've read about the boiler cutouts being a symptom of the fault PCB - but is the continuous call to the pump likely to be part of the same problem ?

thanks

swayzak

 

[swayzak]

Ah - seems it might be:

//www.diynot.com/forums/viewtopic.php?p=253408#253408

..or might not:

//www.diynot.com/forums/viewtopic.php?p=222820#222820



And the vendors had a basic BG boiler inspection done for me a couple of months ago as well.

Well I'm going to make damn sure I get maximum use out of the Potterton engineer tomorrow ...

 

[swayzak]

Any experts think my problem(s) will be solved by PCB replacement ?

thanks

swayzak

 

[superdupergasman]

a pcb would be the last on the list..... and in two months how many times has the heating and hot water run...so alot can happen in that time.

When a service is carried out, it is done to check all is safe...the people are not mind readers and cannot tell if a problem is going to occur tomorrow never mind 2 months down the road.

I would be looking at the zone valves. one will be stuck on.

 

[swayzak]

a pcb would be the last on the list.....

I'm dearly praying you are wrong !

It has cut out once in the last week - and I have seen the continuous pump running problem quoted a few times in relation to the infamous Potterton PCB problem (but not as much as cut-out).

 

[superdupergasman]

Aggg so now you tell us you have a red light on the PCB.

 

[gas4you]

Aggg so now you tell us you have a red light on the PCB.

Where has he said this

As the pcb controls the pump on this boiler then it is suspect.

When the pump is continuosly running, is the boiler still firing up and the HW or CH getting heated?

The pump should run on for about 6 minutes after all demand for heat has finished.

 

[superdupergasman]

Aggg so now you tell us you have a red light on the PCB.

Where has he said this

As the pcb controls the pump on this boiler then it is suspect.

When the pump is continuosly running, is the boiler still firing up and the HW or CH getting heated?

The pump should run on for about 6 minutes after all demand for heat has finished.

Having to reset the boiler to get this to stop, perhaps overheating, thermistor problem or jammed valve.

 

[swayzak]

thanks

Yes - I've had one instance of flashing red light. Had to reset.

The only way to get the pump to turn off is to turn the boiler off.

 

[baxpoti]

If the boiler overheats, the pump will run continuously, until cooled down and then reset.

Check thermistor is not dry (heat sink) and if two port valve system (s plan) check bypass is correct.

If all above ok change PCB

 

[swayzak]

Aggg so now you tell us you have a red light on the PCB.

Where has he said this

As the pcb controls the pump on this boiler then it is suspect.

When the pump is continuosly running, is the boiler still firing up and the HW or CH getting heated?

The pump should run on for about 6 minutes after all demand for heat has finished.

No boiler activity - just on, endlessly whirring away day & night.

Most of the time the boiler works OK - so far it has been just the one failure (which prompted me to get the plumber in).