Why furnace wont start

It is usually located near where the flames shoot out of the burners. It is very easy to remove the sensor with a screwdriver. Clean the probe on the sensor by rubbing it with some medium grain sandpaper. Do a thorough job, but be careful not to break anything. Replace the sensor exactly the way you found it.

Put the front panel back on, turn on the gas, and then turn on the power. Turn up the temperature on your thermostat to see if your furnace will fire up. Check your thermostat. Make sure the temperature control settings are set to above the current room temp. You can try to get the furnace to turn on by setting the thermostat to as high as it will go. Make sure the furnace is on. For instance, draft inducer motor, pressure switches, and circuit board problems could prompt your system to stay off, even when everything else is working properly.

Furnaces are designed with many fail-safes to protect homeowners. One such safety feature turns off the furnace if any access panels are out of place. Push panels back in place, and replace any missing screws to see if that triggers your furnace to run properly. If your furnace is turning on, but not creating any heat, you may have a furnace ignition problem.

If the blower turns on and runs, but the air coming out of the vents of your home is cold, the ignition could be to blame. Here are a few common ignition problems, and how to resolve them. Pilot lights can go out due to system issues, drafts, or even tripped failsafes inside your furnace.

Here are a few guidelines for relighting your pilot light. Electronic ignitions can become dirty from soot buildup on the ignitor. Eventually, the entire ignition sequence will stop operating, which keeps the system from starting up.

Furnace valve design varies, but they often include a little disk with a small handle or lever on it. Other gas valves can look like little boxes, while others still can resemble a lever about the size of your index finger often brightly colored. This valve may have been closed by accident or by someone working on the furnace who forgot to turn it back on. While valves can vary depending on make or manufacturer, a gas valve will typically be in the open position—which means there is gas flowing through the pipe—if the handle on the valve is parallel with the pipe.

If the handle is perpendicular to the pipe, the valve is likely closed. This can be the result of crews working somewhere on the gas line, or there might be a gas leak, a break, or even a blockage in the line. A gas leak can be a dangerous situation, so if you suspect this to be the case, call immediately and follow their instructions. To assess the situation, go outside and check both the street-side and the internal house-side valves to see if they are on.

If they are not on, turning the valve to the open or on position as described above , should get gas flowing into your home once again. Whether due to a technical glitch or human oversight, a missed or incomplete utility payment can result in a service interruption.

Locate the power switch on the furnace itself, which is likely on a nearby wall, or even on a ceiling or floor joist near the unit. It will often look like a regular light switch, but it may or may not be labeled. Put the front panel back on. Turn on the gas, then the power. Turn up the temperature on the thermostat to see if the appliance fires up. Start by checking other electrical components. If nothing is working, call the electric company.

These will be located on the main power distribution panel. Check for a circuit breaker on the appliance, or a light switch located nearby.

Some units have redundant circuit breakers. If any of these circuit breakers are popped, reset them only once. Problem: The float switch is up.