[dam1471]

The furnace runs then later blows cold air have to remove the cover to get it to start the burners again

 

[user_12345a]

how do you expect us to help you?

 

[dam1471]

tempstar furmace

Sorry should have more information. Would like to know what I should look for in trouble shooting

 

[user_12345a]

post a model number.

which access panel? i'm thinking that you reset the furnace by removing the blower access panel; there's a safety switch in there which cuts power.

turn on the furnace with the top access panel removed (assuming it's an upflow) and carefully observe it. board may have a diagnostic led.

if it by any chance has one of those honeywell smart valves, i can't help u. heard they're a pain in the neck.

 

[dam1471]

It does not have a diagnostic led I have removed the panel but it lights every time but wake up in the middle of the night and it is blowing cold air

 

[user_12345a]

you have to catch it when the problem occurs. depends on the ignition system; have a self-contained smart valve and it may fail while the main board times out and brings on the fan.

 

[roughneck]

Are any safety's opening? What's gas pressure? Delta T? Blower running properly? Blower amp draw and shell temp? All registers open? Filter clean? What brand and size filter? Any rollout occurring?
Some troubleshooting may involve working directly with live gas and electrical lines.