Pretty much what the title states, I have a Bryant gas pack that operates like normal when it is in cooling mode, but once the thermostat calls for heat, the system shuts down completely. Even the fan doesn't work. Can anyone list the possible reasons this would happen?

I have a ruud furnace and it won't turn on when set on "auto" mode,its only turning on in "manual" mode and blows heat.The fan turns on when put in the "on"/"fan" mode. I have to turn it off manually once the rooms have reached the desired temp.I could here the blowers start than they shut off...

I have awasher it's a maytag bravos, it fills with water when on rinse mode but does not kick on to spin mode it shuts off with an error code that reads ol on the screen and makes me start over again.what can I do

I have an older lennox unit that is pilot light. The blower motor won't shut off when the temp is reached on the thermostat but it works fine in ac mode. What could cause this? I'm confused because it worked 2 weeks ago when I turned my ac off and the thermostat is in auto and only shuts off when I...