Ive got a thorn back boiler, the front fire lights ok but can't get the back boiler pilot light lit.theres a spark from the igniter but no gas coming through. The boiler is approx 25years old. The boiler was ok untill the gas was turned off then back on again at the mains.

Colin Wakefield, September 2008

Thorn Back boilers can be very awkward to relight as the pilots tend to shrink and dont touch the thermocouple.If its 25 yrs old it will probably be the Housewarmer range.The best way of lighting it is to pull the bottom flap off,use a straw or a pen refill and stick a match in the end.Then push the gasvalve button and aim the taper towards the pilot.It should light but if it does go out after you have held the button in for 30 secs then it is either the t/couple or the pilot needs cleaning out.

Tony S, September 2008