I'd really appreciate advice on this ... Baxi 105e been heating house when hot water on over last few months so aware diverter prob (diaphragm?). Advised by heating engineer doing our service to hold off if it wasn't bothering us?? Over the last week could only get hot water if I powered heating on first and now nothing will power up. It's trying but not firing up and getting flashing alert for fan. Went to get diverter service kit from two places (both out of stock) but completely conflicting advice from both places and two central heating engineers I've called earlier. Last one told me it's a different diaphragm than I went for and that there are two diverters on a baxi (neither have seen boiler this was over phone and given the full history as above). He said go straight for full diverter change at £250. It's a bit of a minefield as need to watch pennies so trying to try and find most likely root of problem to go for first in hopes this will sort it. Really appreciative for any advice.