Just a footnote on this earlier topic. A couple of nights ago, I did finally manage to get to the bottom of this niggling ignition problem.
With the room lights out and the boiler undertray removed, I noticed a slight sparking underneath the contol unit PCB when it was trying to ignite. After removing it (a five minute job) it was apparent that there had been arcing where a diode (component Z3) was soldered into the PCB.
It looked as though this Zener diode had overheated, possibly because of poorly soldered (dry) joints. After cleaning and re-soldering the diode back to the board, and re-installing the control unit, the boiler fired up OK and has worked ever since. Total time taken to fix = 20 minutes.
To be on the safe side, I have ordered a new control board (£107) and will swap them over next week as I don't feel I can trust the original 1993-made (according to the maker's label) unit any longer. Judging by the construction and number of times this contol board is cited as the culprit for problems with the Profile 30, 40 and 50e boilers it really is a poorly designed and manufactured part. Also, considering that there's not a single chip, just discrete components (diodes, capacitors, resistors, relay, etc.) on the PCB, it's a vastly overpriced part and must be hugely marked up by Baxi/Potterton.
Hope that helps anyone with a problematic Netaheat Profile.
A.
PS. Apologies for posting this as a new topic - it was supposed to be posted as a reply to an earlier one.
With the room lights out and the boiler undertray removed, I noticed a slight sparking underneath the contol unit PCB when it was trying to ignite. After removing it (a five minute job) it was apparent that there had been arcing where a diode (component Z3) was soldered into the PCB.
It looked as though this Zener diode had overheated, possibly because of poorly soldered (dry) joints. After cleaning and re-soldering the diode back to the board, and re-installing the control unit, the boiler fired up OK and has worked ever since. Total time taken to fix = 20 minutes.
To be on the safe side, I have ordered a new control board (£107) and will swap them over next week as I don't feel I can trust the original 1993-made (according to the maker's label) unit any longer. Judging by the construction and number of times this contol board is cited as the culprit for problems with the Profile 30, 40 and 50e boilers it really is a poorly designed and manufactured part. Also, considering that there's not a single chip, just discrete components (diodes, capacitors, resistors, relay, etc.) on the PCB, it's a vastly overpriced part and must be hugely marked up by Baxi/Potterton.
Hope that helps anyone with a problematic Netaheat Profile.
A.
PS. Apologies for posting this as a new topic - it was supposed to be posted as a reply to an earlier one.
