Potterton Profile 60e / Grundfoss Pump

[cronic]

Hi folks...

My household HW/CH system (Potterton Profile 60e / Grundfoss Pump) has worked without fault for x3yrs...after the weather recently turned a bit colder i decieded to switch on the CH program on the Horstmann controller....all seemed well.

HW cycle had been working fine....CH cycle came on water was being pumped and radiators warmed up until the room stat was up to temperature....GREAT.

However i then heard that the Grundfoss pump was still whirling round...the HW cycle was off the central heating was up to temp...so i swicthed both the HW/CH off at the Horstmann controller and the PUMP kept on running....and boiler essentially keeps kicking in all the time...HELP....!!!

 

[waterworks]

Hi sounds like you have a micro switch in your motorised valve still making contact, most likely the heating one.
What make of valve/ valves do you have?.

 

[cronic]

I'll have to check tonight...as i'm not at home...guess i should have noted that one down...thanks for the reply.

 

[cronic]

FYI there are two valves...when the room stat was to temp the CH valve closed...

i guess the HW valve would have to be open for the water tank to heat up...even if the HW was set to off on the horstmann controller...

 

[waterworks]

No if you have one valve for heating controlled via your room stat and one valve for hot water controlled via a cylinder stat, they should both close when power removed by turning off programmer.
If they are spring return valves you should see them close, the lever moves and you can feal resistance when they are open the levers go loose, if one of these valve levers stay loose when you have turned off both channels on your programmer then it is stuck keeping the microswitch making contact.

 

[cronic]

That sounds like a simple check...i'll get on that this eve and let you know...

you mentioned its most likely the Central Heating Valve...though i think that one is working fine...? Please could you explain why you think its the CH valve and not the HW valve...

 

[waterworks]

No real reason just that you said that the hot water was fine, but it could quite easily be either valve.

 

[cronic]

Can i just say what great forum/resource...! Thank you Waterworks you were spot on...! Although diagnosing which of the 2 2-Way Valves (SUNVIC) was faulty was not quite as easy...both seemed to be operating the valves...but neither seemed to send the signal to shut down the boiler/pump...

I swapped out the HW 2-Way Valve first with a new unit...rewired and run through the HW/CH programs...No difference both clicked the bolier in but once to temp the pump didn't shut down...

I then swapped out the CH Valve with the HW valve i had just removed...and BINGO...!!! Sorted HW/CH valves now start and stop the Boiler/Pump correctly...

Everybodies happy....except maybe the cats who have now lost their very Hot constantly on radiator...!