Here are some basic trouble shooting tips, should you lose heat (or cooling). These are easy things that a homeowner can do to try and restore the functions of their furnace. Of course you are always welcome to call us over if you do not want to brave your crawlspace!
A few simple things for you to check out are:The thermostat, furnace power and furnace filter. If you are troubleshooting your own problem, follow these suggestions in order.
Since you are dealing with a gas burning appliance, we do not advocate that you remove panels to investigate the insides of your furnace unless you are confident that you can put them back properly. Failure to properly resecure the access doors to your furance can change the airflow within the furnace and create potentially dangerous and deadly situations.
There are many different kinds of thermostats, but they all do basically the same function, send a mild electrical signal to the heater to call for heat/cool (when the temperature in the room is below/above the temperature set) and to tell the furnace to shut off heat/cool (when the set temperature is acheived).
Should your furnace stop responding first look at your thermostat and make sure that it is set for a temperature that is above your ambient room temperature. Remember that the location of your thermastat is where it measures ambient temperature, so it is often the case that your temperature in other areas of the house may be cooler or warmer than where your thermostat is located.
Next make sure that if there is a switch on your thermostat is set to the propper need. Generally there are one or two switches on a thermostat. The first tells it whether you need "heat" or "cool" and the other controlls the furnace blower, "on", "off" or "auto". In the winter you would have it set to call for "heat" and the fan set to "auto" in the summer, "cool" and "auto".
If you have a digital thermostat, make sure that you see the panel is getting power. If there is no power to the panel give us a call or seek your thermostat's user manual out and check to make sure the wires are connected properly. Before working on the thermostat be sure to turn off the power switch at the furnace. The thermostat works on a 24v current, so enough to give you quite a shock, and also enough to short out the circuit board in your thermostat should a wire accidentially come in contact with metal in the board.
Sometimes there are reset buttons on digital thermostats, you can try this as a last measure, but write down your program as this will erase any pre-programmed times and temperatures.
Beside or near your furnace will be a light switch, this controls the power to your furnace. Sometimes when your furnace does not respond to a request for heat from your thermostat, it is a power issue. First, check to make sure that the switch is in the "On" position. As obvious as this sounds, with furnace locations sometimes in a closet or other confined space, the switch can get inadvertently bumped and turned off. Though if the switch were on when you looked, turn it off for 15 seconds then back on. On some furnace models this will reset the furnace computer and sometimes that is all it takes to regain control of the furnace. Of course if this does solve the issue, or if it works, but the issue repeats, give us a call, as we will need to discover where the failure is taking place.
Though less common it is possible for a badly clogged filter to cause your furnace to shut down. A quick check is to pull the filter out and shine a flashlight behind it, if you can see most of the light coming through then your filter is not causing the issue. Though if your filter is opaque and you see little light coming through, then try and start up the furnace with the filter removed. If it works, replace the filter and be relieved that it was a simple issue.
Depending on the type of furnace you may have several filters, some even in the blower compartment of the furnace, which would require you to do some dissasembly of the unit. Please only do this if your comfortable with the workings of your furnace and confident that you can put it back together again with everything in its place. Failing to properly resecure the access doors to your furance can change airflow within the furnace and create potentially dangerous situations.