Central heating staying on

Hi, once again I have another problem with my Boilermate 2000.

Last year, the middle pump (central heating) seized up but an engineer managed to fix it by manually turning it with a screwdriver and some WD40.

The pump finally gave up the ghost 2 days ago, making a loud grinding and clunking noise.

I've had an engineer out to replace the pump but now the central heating won't switch off, either by the thermostat or the timer. LED 3 stays on and the only way to turn the central heating off is to switch the boiler off at the wall.

Anyone any idea what could be the problem?

edit: Should have mentioned that when I press the switch to cycle through the readings I get...

75
ERR
H60

I'm guessing that 2nd reading is a problem?

Yes you have an error code.
But I would say your main ACB has failed (PCB)
Mike