The wall furnace is a complicated machine, but are not prone to problems. However, if such a need arises and it needs troubleshooting, it is best to read the user manual to understand the different parts of the furnace. It is always advised to leave such items for repair only by technicians who have proper precautionary measures in place. Due to the high temperatures, it can lead to a hazard in case of mishandling. Following are the major areas where a problem can occur.
If the blower does not start, it may be due to some faulty connections. The factors that might contribute towards it are dirty connections, broken wirers, or no power due to faulty switches or connectivity problems. Since the blower is directly affected by the thermostat, there is also a possibility of a bad thermostat for the blower not being able to power up. If none of these are present, then the blower may be at fault with its motor being burnt a blown fuse. Keep the thermostat wires away at all times which completing the check.
In case the blower does start but is not able to sustain the pressure and dies out before the appropriate temperature is reached, it may be due to low gas pressure which would mean checking the wiring again, inlet and outlet vents being blocked due to dirt or dirty burner leading to resistance to proper rotation of the motor. It can also be a result of faulty control board or electrodes not being in perfect working condition. Corrective measures would include taking the right directions towards the problem area. Unclean furnaces are the major reasons for consistency problems.
At times the burner may be working well but the heat does not reach the desired levels of temperature. If the blower is working fine, the problem remains with the gas supply. If the optimum amounts of gas are not able to reach the furnace, the heat would always remain insufficient. Check the gas tanks for gas availability and the pipes for proper flow of the gas. A dented pipeline can reduce the performance to a great extent. Replace or repair whatever is necessary.
There are times when the blower may run without ignition which can be a result of fault motors. Sometimes the switch may turn bad or a bad gas supply may cause the problem. If the thermostat is not working properly, it may not be able to calibrate the temperature and provide no cut off mechanism. Effectively speaking, the cut off mechanism is supposed to break the battery connection which stops the motor till ignited again.
The majority of the problems arise due to improper upkeep of the wall furnace; it should be serviced and cleaned from time to time for its proper functioning. They are sturdy machines and any problem encountered may mostly be due to human error.