If you are wondering what could be causing your furnace not to work despite the thermostat and power switch is alright, you should consider checking the safety switch.
This is something that should be in your troubleshooting manual and should be easy to deal with.
It is a mechanism that protects the furnace by ensuring the fan and burner do not come on when the panel is removed. A furnace safety switch will always pop out whenever the door is pulled. This ensures that the furnace does not work without the door since it is needed to activate the furnace. You may have to install the safety switch if it is an issue. Rather than call an HVAC specialist and spend money on these repairs, start by first switching off the power source. Next, prep the blower door and then wire the safety switch. This is easy but if you are unsure, consider asking for help from an electrician. Alternatively, ask the HVAC professional to handle the entire process. Once you handle the wiring stage, check and test your complete installation. Homeowners need to familiarize themselves with some of these processes to avoid incurring unnecessary HVAC repair costs for things they can handle. This is something you can quickly learn by observing what your HVAC technician does every time he comes over to fix an issue with the unit. It is even more critical to ensure you carry out regular maintenance practices, making a huge difference. Schedule annual HVAC tuneup sessions to have expert HVAC professionals identify and fix the issues in advance.