If you are wondering what could be causing your furnace not to work despite the control equipment as well as power switch is alright, you should consider checking the safety switch, however this is something that should be in your problemshooting manual as well as should be easy to deal with. It is a mechanism that protects the furnace by ensuring the fan as well as burner do not come on when the panel is removed, however a furnace safety switch will consistently 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, then you may have to install the safety switch if it is an issue… Rather than call an HVAC specialist as well as spend cash on these repairs, beginning by first switching off the power source, next, prep the blower door as well as 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 as well as test your complete installation, and homeowners need to familiarize themselves with some of these processes to avoid incurring unnecessary HVAC service costs for things they can handle. This is something you can abruptly learn by observing what your HVAC specialist does every time she comes over to service an issue with the unit. It is even more critical to ensure you carry out usual service practices, making a large difference, and schedule annual HVAC tuneup sessions to have expert HVAC professionals identify as well as service the complications in advance.