Does anyone know how to reset the alarm on wireless thermostat receiver?

I desperately need help...3 years a go i had a new heating system installed with Britsih gas.

Yesterday i noticed the temperature in the house to be really hot despite the thermostat showing the heating was off. The strange thing was the radiators were all hot.
I went to the boiler and noticed no green light on the wireless receiver box, so i checked the fuse to the mains which powered the receiver and both the green and red alarm light was lite.
I have no control over the heating and despite trying the most lodgical things like changing the batteries in the thermostat and trying to reset the receiver box, unfortunately neither resolved the problem.
British gas want to charge lots of money just to come out and god knows what else on top when they get here.
If this problem can be resolved by me then i would atleast like to try. Any helpful suggestions will be gratefully received.