Advice please. Baxi Solo 2 playing up as usual every winter. Waiting on 2 heating engineers getting back to me with quotes for boiler change. Trying to keep boiler running till they reply. Anyway problem being when switching on, the boiler on lights on,the fan light is on and the fan is running but then no spark is generated.The troubleshooting guide suggests it is the pressure switch so to test I made the contacts and spark was generated.So I fitted a new pressure switch but still no spark so I was wondering if fan is just not running fast enough to generate draught for pressure switch. Also any advise on which heat only boiler anyone recommends for replacement.Thanks.