Hi, This boiler is not firing up when the temperature drops on the room thermostat. It is an intermitent fault and seems to happen more in the middle of the night. To fix it I have been turning the power off and on at the wall. After this it immediately fires up again. Can you advise what it might be and any further problem determination I can do to try and narrow down the problem before I call an engineer. The boiler is about 15 years old. Since I've been using it for the last
6 years it has had this problem. Though it used to only happen once a month it is now more of a daily occurence. I had it serviced 2 years ago but as the problem was not demonstratable the engineer said he couldn't look at it. Your advice is appreciated.