Gas boiler won't shut off.
I have a Vaillant gas fired hot water boiler (GA 92 Series). I woke up this morning and the temperature in the house was 8 degrees higher than the thermostat was set at. I figured the problem was the thermostat. I disconnected the thermostat and the boiler still runs. There is only one thermostat and one zone in the house. I looked at the boiler and found where the thermostat wire connects (in the control unit). It is labeled a Honeywell Aquastat Relay (L8148E). I tapped the side of this unit and the boiler went off. I figured something was sticking. I thought it was fixed. The boiler fired up again and will not shut off. Therefore, I turned off the boiler at the breaker box. What to do now?