I have a goodman heater. Its about 3 yrs old It's a goodman ght . My honeywell thermastat turns on the unit but no hot air comes on. I had the hot surface igniter tested and its fine. What else could the problem be?

I have a goodman heater. Its about 3 yrs old Its a goodman ght . My honeywell thermastat turns on the unit but no hot air comes on. I had the hot surface igniter tested and its fine. What else could the problem be?

What do you mean that the thermostat turns on your unit but no hot air comes out. What then does it turn on and in what order. How did you test the hot surface igniter? Did you check the continuity? Did you check the voltage going to it. You said the igniter was fine, does that mean that the igniter gor almost white hot as the furnace with through the cycle.
Did the burners ever attempt to fire up, if so how many times and last did the main blower ever come on??

Give some more info and maybe someone can help you.

Go to the H&AC sticky at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html Check the sequence of operations of a gas furnace. Note where yours stops. Read the section on that component. If that doesn't help you fix the problem, post back with what you found.