Common problems with Coleman furnaces include issues with the pilot light, insufficient heat and difficulties starting. Some of these problems can be avoided with proper furnace maintenance.
Unstable pilot lights are one of the most common problems with Coleman furnaces. This is often caused by the placement of the thermocouple. When this part of the Coleman furnace is placed too far from the pilot light, it can't operate properly. This device has a sensor inside that, when properly functioning, is heated by the pilot light. This device sends an electrical charge to the furnace that prevents the gas valve from closing. When the light is not staying on, the thermocouple may not be properly communicating with the gas valve.
When a Coleman furnace is not producing a sufficient amount of heat, the air filters may be the problem. Cleaning these filters and ensuring that the vents are open is likely to resolve the problem. Other potential causes include dirty burners or a failing blower motor.
Another common problem is the furnace's ability to start. This is often caused by a failure in the power supply and can be resolved by ensuring the device is plugged in and by checking the circuit breaker. Other potential causes of this common problem are an overheated motor and a malfunctioning gas valve.