About 2 hours after the last cycle of the day my bolier comes on and heat the hot water. If I switch the boiler off (not at the mains) the system continues to makes very loud noises like the water is boiling over. I can stop it by switching the whole system off at the mains. This is all in one presurised system??? Help!!!
sound like problem with micro switch sticking you dont specify the boiler but ive listed a fix for jaguar/glow worms on fixed for free.com jaguar boilers under heading boiler showing f1 may be worth a look
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.