HVAC fan still running after 150 seconds

Hello!

I have a Trane XE90 system. Lately, I have noticed after the heat stops flowing, the fan will continue to blow. Even if I shut off the unit at the stat, it will continue to run. The longest it ran for was almost 45 minutes (that I'm aware of). I have replaced the filter in the system. The only way I can get the system to stop if by switching off the emergncy switch at the unit itself. Once it comes back on, I can turn the heat back up and it usually works fine for a while.

I cannot find the relay anywhere inside this box. I have tried looking online for pictures, but I'm starting to think it is mounted on the board, itself. I believe it is a model number 50a50-472 from Winter-Rodgers?

I did see an error at once point (blinking 5 times) that says flame is lit with no gas flowing. This is when the unit was still running after heat stopped.

I was going to replace the thermo today, but am I wasting my time? Does anyone know where the fan relay is on this unit?

Thanks,

Chris

 

Your problem description matches mine. Also wondering where the fan switch relay is. Here are some pics of my heater, perhaps that helps if similar to yours.

Any help is appreciated! thanks.

 

Nah, sorry man! Mine looks nothing like that. I will upload pictures later when I get home. Going to pick up a new stat just incase and try that. If it doesn't work, I will just return it... lol.

Might just have to call an HVAC tech

 

Anyone? Trying to see if I can figure this out before contacting a company