Need Help! I came home to find my family freezing because the HVAC system stopped working. The thermastat has no display. The HVAC company want 200$ just to drive two miles up the road. I figured I would give this a shot before giving money away. I think it may have something to do with a fuse or the contact? However, I am not sure. Any assistance would be great. Please send info to [email protected]

Sincerely
Ben wall

Does your thermostat have an internal battery that could be dead? Most stats also use 24vdc from a stepdown transformer wired into your hme, check all circuit breakers too.

Its 24vac... not 24vdc don't get confused. Probably 3amp fuse on control board... loose wire connection at thermostat... could be bad thermostat... bottom door of furnace came off... tripped limit... bad control board... transformer... Not a whole lot homeowner can check.
Have fun!

Yes on the AC. I have to disagree about the average homeowner being able check many of the common problms. With a few tools, they can tackle even bigger problems. One great tool is the sticky at the top of this forum.

To do simple checks like this you do need some tools. A test light, a meter, or a voltage detector might be the best place to start with. I came across the niftiest gadget for trouble shooting, a voltage detector. They work through the insulation of wires. There are several brands. I have a GB Instruments GVD-505A, less than $15 at Home Depot. Touch it to a hot wire, and the end glows red. Find the doodad that lights it on one side, and not the other, and you have the culprit. You do not have to open up housings and expose electrical contacts. You are looking at where your hand is, not where the meter is. Most people are capable of doing repairs and will get it going and not get hurt if they use a little sense. The voltage detector makes it even easier.