If anyone could help it would be great. I have a Baxi Solo 24HE boiler, for last few years having a problem where red lockout light comes on when trying to fire up. GRaduallly gets worse until the point it wont fire. A quick 10 min strip and clean igntion probe with a bit of emry and re-fit and it fires up straight away and can last months before fault back on. I did last year replace with new igntion probe and had no fault for 9 months or so, maninly during warmer months. Then of late fault coming back on and in last two months I have had to stri pand clean twice. Appears rust build up on end of probe. DOes anyone know why this is happening and how I can fix. Had a few repair guys out with no success???? PLease help