Boilermate 2000 not working

I have a Boilermater 2000 with a Potterton Suprima 40L boiler

The heating and hot water have both stopped

The Suprima has been problematic in the past so was my first port of call.. a PCB swap, Thermister and air sensor later we found it was the flow sensor not switching on..

On the boilermate the right hand pump was running continually, the middle pump was not doing anything and the left hand pump (boiler return) was red hot and buzzing so I disconnected this pump and let it cool down, re connected it and it started pumping and the Suprima fired up straight away.. lasted about 2 minutes then the pump started buzzing and got hot and the Suprima locked out.

I assumed the pump was faulty and switched off the Boilermate at mains and swapped out the pump with a proper Gledhill XB004 (expensive pump!)

Heating still not working!

Now this is where I'm up to:-
When I switch on the Boilermate, the right hand pump starts whirling straight away.. All three green led light are on. Then after approx 1minute later later the right hand pump stops and the top led goes out, the bottom two stay on. The PCB initiates itself and about 3/4 minutes later the Suprima led flashes as if its being called for heat. The boiler goes through the sequence but doesn't fire up and locks out..  If I run the hot water tap the right hand pump will start up again but the top LED does not come on. If put the clock in the middle setting the new left hand pump runs but this flow still doesn't start the Suprima which still locking out.

So not sure if the pump I changed was even faulty or whether it was something else now... Everything seems to work on the boiler end and everything seems to work on the Boilemate end yet its still not! so frustrated!

If the DHW or PHE sensors where duff what would be the symptoms?


Please help as I've been 4 days without heat now!

Bm 2000.
Any fault codes?
Mike