CH Boilermate 200 & Suprima

Hi,
I have a Boilermater 2000 and a Potterton Suprima boiler.
We’ve not noticed hot water issues, but recently the CH seems to be failing or taking ages to come on when asked.
Looking at the Potterton (set to Max) it seems like its being asked to come on, but it doesn’t. (Click – green light)
The boiler pump is spinning, the CH pump is not.
When I check the Heat store temp – its below 60.
I'm not 100% certain, but it seems when I reset the boiler, it fires up after a time. When the store hits 60, the CH will come on.
This will then turn on and off as per the temp store <60 or the thermostat. (Correct function)
The boiler pump seems to be continually running (or is whenever I check)
I cant work out why the temp store drops below 60 and the boiler doesn’t fire.
(I could be mistaken, but It seems if I let the CH drop to low (off for long period) it struggles to regain normal operation – which is obviously wrong!)
Could it be Boiler thermistor?  Boiler pump?  ANO
Appreciate any suggestions.
Regards

Hi, it sounds from the symptoms you are describing that your control board in the Gledhill is on the way out.  This video gives an indication of how the system works when it is behaving correctly.   Click text below to view.

Normal operation

This video shows a pcb when it has failed completely and the typical indications that it has failed.  Faulty PCB

Sometimes the pcb's will slip in and out of failure mode for a while before finally packing up completely, often a power off and on will make things work OK for a while before it starts to act up again.

I can offer reconditioned pcb's or can repair them get back to me if you want any more information.  Regards Murray

Thanks Murray,

Helpful videos - thank you!

So the next time I seem to loose CH, and the bottom LED is lit (calling for Boiler)  I need to ensure the request is actually leaving the board.
If not - its the board, If it is  - its something within the boiler?
Only it seems to be asked to fire up, but it doesn't: Green light - click - .....nothing. (I realise i need to confirm this)  That's why I was wondering if it could be the boiler thermistor/ gas solenoid or something else.

Thanks for your help

Hi first thing to note is there are no situations where only the bottom LED will be on on its own, the bottom and second up should be on together as the second one up is the boiler circulation pump. The second one up will stay on for about 3 minutes after the bottom one has gone off, this is normal it is called pump overrun and is designed to remove the last bit of heat from the boiler and to stop the boiler tripping on overheat. If the two bottom LEDs are on the signal for the boiler to run should be there, if it is not then the pcb is faulty. Another classic sign of board issues is the hot water pump, far right, running all the time even when no hot taps are on. Hope this helps.

mmartin wrote:Hi first thing to note is there are no situations where only the bottom LED will be on on its own, the bottom and second up should be on together as the second one up is the boiler circulation pump.  The second one up will stay on for about 3 minutes after the bottom one has gone off, this is normal it is called pump overrun and is designed to remove the last bit of heat from the boiler and to stop the boiler tripping on overheat.  If the two bottom LEDs are on the signal for the boiler to run should be there, if it is not then the pcb is faulty.  Another classic sign of board issues is the hot water pump, far right, running all the time even when no hot taps are on.  Hope this helps.

Hi Murray,
Sorry - I understand what the LED's indicate, and that the bottom two would be lit together (mostly).
I was trying to explain that the card does indicate that its requesting the boiler to come on, but the boiler doesn't. (i still need to confirm if the request is actually leaving the BM)
I thought someone might say oh yes, that's a common fault with the board relay  - or,  no it sounds like a boiler issue etc etc.
JFI, the HW pump is not running all the time - i guess that's good news!

Again, i appreciate your help/comments - i've learnt a lot - Thanks!

Hi, you obviously will need something that allows you to see if the pcb is pushing a supply out to the boiler. Ideally this would be a multimeter, or a decent neon screwdriver might suffice. If you consult the manual page 22 it has a circuit diagram. The switch live to the boiler comes out on connection 7, boiler SL (switched live), you will obviouly expect to see a permanent mains on connection 6. These pcb's use solid state relays to control the external items so sometimes the voltages may appear a little lower than one might expect but still above 200V.

Obviously you need to be careful as this will be mains voltage. I know it is stating the obvious!!

Let me know how you get on. Regards Murray

This is a link to the manual online: http://www.gledhill-spares.net/documents/BM2000-Iss10.pdf