Hello. I have a Worcester Bosch 24i boiler which has recently refused to fire up either when switching on the CH or HW. The green light flashes as if it is about to fire but doesn't and after a minute or so the blue light flashes and the boiler locks out. Occasionally, the boiler does fire up but not consistently. I have found that if I get the HW to fire and leave it on for ten minutes, then switch on the CH the radiators start to warm up. After a further ten minutes I switch off the HW and the CH remains on. Is this a boiler issue or something linked to the boiler?
Thanks.