Promax 18 sl over heating issue.

[ABGS87]

Hi Guys,

I'm looking for a bit of advice/confirmation of what i think the fault is.

got called to a promax 18 sl last week thats not firing up and going straight to dry fire.. the engineer before me diagnosed a PCB and i was just sent to fit it, alas this achieved nothing (not sure how he came to the conclusion it was the PCB in the first place!). checked that the system was full of water, it was. the pump is spinning away perfectly but still no joy from the boiler. i then disconnected the inline connector on the flow switch and bridged it out with an electrical screwdriver and the boiler fired up, ran for approx 20 seconds and started to crash and bang like there was no tomorrow. i then felt the pipework from the boiler and it was heating up the return. its not piped up backwards as i checked that initially and it had been in the property for around 5 years working perfectly.

basically I'm thinking its the heat exchanger thats got a blockage in it preventing any flow through the boiler causing it to back up the return pipework?

just wanted to know if anyone has experienced this on the promax's/solo he's and if you have a different diagnosis to me from the given info?




oh and as this is my first post on here and none of you know who i am my GSR is 168545 and license number is 3066104.

cheers in advance for any help!

 

[lame plumber]

still need to see a mod and some posts I expect for an answer, and I expect we'll be seeing that no used all over the country soon

 

[ABGS87]

still need to see a mod and some posts I expect for an answer, and I expect we'll be seeing that no used all over the country soon

fair, i only put the number in as it states to put it in a thread first and in the hope that someone would be able to give me a quick answer. thread was also meant be titled promax dry fire issue! thats what happens when your thinking about something else whilst typing! ha