Got a call on Friday night from a friend whose Baxi 105e combi stopped firing up, when all the family were arriving at the weekend for a long stay. After running through the possible failures to ignite, I found the main gas valve solenoid coil was open circuit. Managed to get a new one on Saturday morning but it was the base Honeywell part, so I had to transfer the modulator across. Failure had likely been accelerated by the secondary heat exchanger furring up, resulting in the valve continously cutting in and out in hot water mode, as the primary temperature had been going up over 80 in an effort to get required power transfered through the plate exchanger. Anyway, replaced the gas valve, and defurred the plate exchanger (and whilst the boiler was in bits, cleaned out the burners, flue, etc), recommissioned, and it's all running perfectly now.
Anyway, to the meat of the question... Have a burned out gas valve left over. Is it possible to get just the replacement coils for these? If so, and if they're cheaper than a whole valve (£56 + VAT), this would seem like a sensible thing to repair ready for next time it burns out (maybe in another 4 years time?). Not to mention than no one seems to keep stock of this Baxi part anyway, which would be another reason to have a refurbished spare ready to go on the shelf.