Will not start, replaced thermostat to get heat. now it will not start at all

Pull the power red wire off the thermostat and batteries out if it has battery backup, then reinstall...much like a computer restart. If this doesn't work, then replace your thermostat.

AC temperatures are controlled by thermostats, mechanical or electronic, As per your question it does work some times means thermostat is working some times. Please spray contact spray in thermostat, or replace thermostat. BTU (BRITISH THERMAL UNIT) denotes cooling capacity of AC.

Sounds like a bad thermostat...There is one (some models two) disc type thermostats, about the size of a quarter that are wired into the heating element circuit. Take the back panel off and find the heating element. There should be a thermostat with two wires attached connected to the heating element. Unplug those wires and remove the thermostat and replace it. Be sure the unit is unplugged before you start.

what is your model number is then we can get started then

If before you change the thermostat,if the car has always had that thermostat in it,and the heater heated before and the engine is not overheating,the thermostat is most likely fine.But that is the cheapest way to start,Lissa is on the right track there.The heating element may need replaced..

It is likely that either the thermostat has been removed, or, if you have had the vehicle for several winters with no problems, the thermostat is stuck wide open. Either way, you are on the right track with the thermostat. Replace it and your heat should come back.

I would check a couple things lets start with the thermostat itself remove from the wall mount and check to see if the red and white wires are attached. Does this thermostat take batteries? If so replace the batteries. If still no heat make a jumper and jump out the red and white wires this should turn your heat on and now means that it is a thermostat problem. Purchase a new one and pay attention to all of the wires and where they go.Good luck

The problem is either of the cycling thermostat, high-limit thermostat or the gas valve solenoid coils sitting on top of the gas valve assembly. Disconnect power then verify any of these condition by bypassing the thermostats. Refer to the image below and locate the thermostats.

Note: This is an image of an electric dryer but the thermostat and the thermal cut-off (cut-out) locations are the same.

Disconnect each of the thermostat wires then connect and insulate them properly. Once done, reconnect power and start the dryer. The gas valve solenoid coils are indeed faulty and both need to be replaced if the problem still persists. Click here for the procedure in replacing the solenoid coils.

Gas Valve Solenoid Coils Replacement Procedure

Either or both of the cycling thermostat and the high-limit thermostat are malfunctioning if the dryer continues to heat up with the thermostats bypassed. Disconnect power then reconnect the cycling thermostat wires but keeping the high-limit thermostat bypassed. Reconnect power then start the dryer. The high-limit thermostat is the culprit if the dryer continues to heat up. If not, then the cycling thermostat is the culprit.

Also do the other way; that is reconnecting the high-limit thermostat wires but keeping the cycling thermostat bypassed. The cycling thermostat is the culprit if the dryer continues to heat up. If not, then the high-limit thermostat is the culprit.

Replace the faulty thermostat and it should solve the problem.

The cycling thermostat or the high-limit thermostat may not be the problem but rather the gas valve solenoid coils sitting on top of the gas valve assembly. Disconnect power then verify this condition by bypassing the thermostats. Refer to the image below and locate the thermostats.

Note: This is an image of an electric dryer but the thermostat and the thermal cut-off (cut-out) locations are the same.

Disconnect each of the thermostat wires then connect and insulate them properly. Once done, reconnect power and start the dryer. The gas valve solenoid coils are indeed faulty and both need to be replaced if the problem still persists. Click here for the procedure in replacing the solenoid coils.

Gas Valve Solenoid Coils Replacement Procedure

Either or both of the cycling thermostat and the high-limit thermostat are malfunctioning if the dryer continues to heat up with the thermostats bypassed. Disconnect power then reconnect the cycling thermostat wires but keeping the high-limit thermostat bypassed. Reconnect power then start the dryer. The high-limit thermostat is the culprit if the dryer continues to heat up. If not, then the cycling thermostat is the culprit.

Also do the other way; that is reconnecting the high-limit thermostat wires but keeping the cycling thermostat bypassed. The cycling thermostat is the culprit if the dryer continues to heat up. If not, then the high-limit thermostat is the culprit.

Replace the faulty thermostat and it should solve the problem.

Had similar problem, continuous fan, turn off power, then won't start up. Replaced thermostat, no change. The main controller board in the furnace went bad. What was weird was that it happened in the summer, while the heat was turned off. One day I noticed that the fan was running. The thermostat was in the off position, and I had to shut off power to the furnace to make it stop. I forgot about it till heating season came along and it wouldn't start up. The preliminary blower would start, the gas would click on, it would light, then quit. After tracing and checking the various safety switches, etc. it became apparrent the main board was bad. I found one on ebay, replaced it, [a simple job, unplug, a few screws, replug] and it's been working fine..good luck, John