My furnace does not kick in. A.C. Works so I know its not fan. The red led is constantly on. I just hear a slight humming sound. No water in the small rubber hose. Thermostat turned up high... could it be heat sensor?

The humming you hear,, does the draft inducer motor come on?
That is the 1st step,first thing you should hear after turning up the tstat,, if motor is bad and its not running it should feel very warm to the touch

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Originally Posted by wmproop

the humming you hear,,,,,does the draft inducer motor come on?
that is the 1st step,first thing you should hear after turning up the tstat,,,if motor is bad and its not running it should feel very warm to the touch

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The humming is a slight electrical type humming. My A.C. works normally... blower fan comes on and blows cold air. When I switch to heat... nothing at all. My red LED is constantly on... which is a good thing I think... What else can I do before I make the call?