A customer tells me, an engineer had visited the boiler & followed the MI instructions.
No heating was the problem, but dhw worked.
Heating calling, boiler fires up for brief seconds, shuts down, no pump running. after voltage checks as per MI.
Changes PCB.
Still doesn't work !! He walked away !!!
So I checked the same things, also the ntc's [which can be a problem on this boiler that makes it look like a faulty PCB]..... MI's saying it's the PCB.
Knowing the PCB had been changed, I had a gutt feeling it couldn't/shouldn't be a faulty new PCB.
Then realising that the Dhw doesn't use the pump on this boiler, I pulled a lead off the Dhw flow switch, heating fired up with pump on.
So because the Dhw flow switch was stuck on, the boiler was briefly firing then shutting off, on the NTC & not letting the heating on.
New flow switch job sorted.
Hope this info helps, sometimes it's best to use your experience & gutt feelings, it also can save you driving around with an expensive PCB in the back off your van wondering when you can use it!!!
Aggis
No heating was the problem, but dhw worked.
Heating calling, boiler fires up for brief seconds, shuts down, no pump running. after voltage checks as per MI.
Changes PCB.
Still doesn't work !! He walked away !!!
So I checked the same things, also the ntc's [which can be a problem on this boiler that makes it look like a faulty PCB]..... MI's saying it's the PCB.
Knowing the PCB had been changed, I had a gutt feeling it couldn't/shouldn't be a faulty new PCB.
Then realising that the Dhw doesn't use the pump on this boiler, I pulled a lead off the Dhw flow switch, heating fired up with pump on.
So because the Dhw flow switch was stuck on, the boiler was briefly firing then shutting off, on the NTC & not letting the heating on.
New flow switch job sorted.
Hope this info helps, sometimes it's best to use your experience & gutt feelings, it also can save you driving around with an expensive PCB in the back off your van wondering when you can use it!!!
Aggis