We have an Olsen bcl-120s furnace and a York model thermopump. These are connected to a Robertshaw thermostat for bi energy regulation. At -12 Celsius, the furnace is supposed to be the source of heat for our home. However, when this happens, the furnace no longer follows the thermostat settings and burns non-stop, only pausing to prevent itself overheating. Our house overheats terribly. We have been looking online at wiring diagrams to see if we could diagnose/fix the problem ourselves, but haven't found anything helpful.
This only started happening after a service technician rewired the thermostat.
Can anyone suggest something to help us?