Alpha cb28x cut out

[AllyBongo]

Going to this prob tomorrow, guy says the heating is working fine but when he uses HW its runs for briefly then cuts out, if he resets it, it fires again for a bit before cutting out. Suspect it could be blocked dhw exchanger, is this common? The jobs far out of town, so was wondering if it would be worth taking any sensors/thermistors? Also noticed in MI's the cb 28x has no dhw sensor, just a flow regulator, Could that be a possible prob?

Appreciate any help

Ally

 

[Billy Bob Bob]

sounds like limescale,corrosion or divervter jamming,check flow reg for restriction/damage it is common for plate heats to block up if the systems dirty

 

[AllyBongo]

Cheers gasman, any way to check the exchanger???

 

[Billy Bob Bob]

thats a difficult one generally if flow pipe gets hot when running to dhw only diverter valve may be dumping down this can be caused by a blocked plate heat if thats the case then both parts will need renewing you can get the diverter from abkot poss plate heat as well,problem you have is getting i9t to run long enough to test this theory out

 

[AllyBongo]

Thought that would be hard to test, i'll check it out tomorrow. Cheers mate

 

[AllyBongo]

Problem sorted today, someone had serviced the boiler a few weeks ago. Seems they had knocked the hw flow switch off its seat, tested the switch and it was fine, put it back on properly and it fired up no probs. hw was only coming on for a bit because the heating was running at the same time

 

[Billy Bob Bob]

glad you sorted it