BM 2000 + Potterton suprima 40

Hi All,

Got a curious issue with our heating / hot water system.
It's been working happily for abot 11 years, had a new gas valve and updated pcb on the potterton about 5 years ago but other than that fine.

Now we have a problem with it,
The thermal store will deplete it's self so then we have no hot water or heating
the only way to get the system to work again is to put the BM emersion on for about 10 minutes turn if off again then the BM will fire up the boiler then be fine again for about maybe 3 days then have to go through the same cycle again.

What kind of things should i be looking for here to narrow down what the issue might be.
I don't personally think it's an issue with the boiler as when the BM is pushing out heat it fires up the boiler as and when required.

I've checked the header tank for the BM ans that has plenty of water, even tapped the pipe work between the 2 to make sure there is no trapped air.

Sounds like the Pumps are working, one is always running (At work at the moment so i'd have to check to see which one)

Thanks

Pump should not always be running!
Mike
MGC/H2O
Norfolk

Thanks Mike,

The pump that is running constantly is connected directly the the what i believe is the thermal exchange.
the other 2 pumps are labled Primary return to boiler and Heating flow pump, they are both silent.

the 4 green bulbs HL1 -HL4 are all lit
There is nothing displayed on the LED display at all at the moment but i will check it later again

we have run out of hot water again now

DHW pump running?

Yes that's the one, it's always running, you can tell as if you change the flow rate switch the tones change
It even runs when the emergency hot water is turned on

You haven't got a leak on your DHW supply any where have you?
To check just turn the water off and after a few minutes DHW pump should stop.
It could be sensor trouble.
But it may be the ACB.
Mike
MGC/H2O
Norfolk

Ok i've had the emergency on for 30 mins
Just turned it off and it's all kicked into life.

The DHW Pump is no longer pumping
The LED is showig on
The only 2 green lights are boiler on, and boiler pump, the boiler is boiling away now

Still getting the same issue,
Can't find any plumbers in the woking area that know anything about these units.
Is there a sensor that would be worth replacing to rule things out

Gone through the fault codes?

Hi Mike,

No error codes get displayed, the system filas the LCD just goes blank

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