I have a strange problem. I have a oil system in my house and the heating and water is on timer coming on around 5.30pm and going off at 8.30pm. In the middle of the night at around 2am and again at 4am (the times do differ) the heating comes on all by itself. When I go to the airing cupboard the lights are not on to say that the heating is on all I can hear is the noise as if there is water running through and also the radiators get hot. The heating is normally on for around half hour to a hour and then goes off again, I have tried to switch the heating to off but it does not work. It has been freezing outside the past few days and the boiler is outside in a brick shed could this have something to do with it? I have only lived in the house a year and I think that the whole system has been in the house around 13 years. Please can you help because it is going to end up costing me a fortune in oil!!!