How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Rick Mather Your Own Question
Rick Mather
Rick Mather, HVAC Technician
Category: HVAC
Satisfied Customers: 3634
Experience:  35 years experience, HVAC
Type Your HVAC Question Here...
Rick Mather is online now
A new question is answered every 9 seconds

I have a Trane XV90 furnace. Water is dripping from the upp

This answer was rated:

I have a Trane XV90 furnace. Water is dripping from the upper area, behind what appears to be a small exhaust fan module connected to the combustion chamber. This water is dripping down to the lower compartment, and seeping out onto my floor.

Is this a common failure? Perhaps a gasket? How might I fix it cheaply? I recently replaced the main control board myself, with an $125 part I bought on ebay, and saved about $650. So I'd really like to avoid the major $$ outflow.
There is a drain on that unit. clean the trap that most likely has dirt in it
Customer: replied 8 years ago.
If you're referring to the drain hose on the exhaust fan housing, it appears to be draining fine.

What trap are you referring to? Perhaps I am not seeing something.
Rick Mather, HVAC Technician
Category: HVAC
Satisfied Customers: 3634
Experience: 35 years experience, HVAC
Rick Mather and other HVAC Specialists are ready to help you
Customer: replied 8 years ago.
Ok, I think I understand what you're saying about the trap. The trap is on the bottom of the furnace, mounted beside the control board, with two hoses going in, and one going out (to the sump), and it is not leaking, but I'll take it off and clean it anyway. All drainage associated with the piping/hoses appears to be working correctly, including the sump system. I understand basically how this furnace works with regard to condensate drainage.

The problem is a water leak which appears to me to originate behind the combustion exhaust fan, which is in the upper part of the furnace. The leak is definitely NOT from the condensate piping at the exhaust fan, but behind it.
Customer: replied 8 years ago.
The trap is not clogged.

Hello X, Rick is offline so I thought I would pinch hit for him. If you accept, please click on one of Ricks replys.


I have this furnace and have serviced quite a few. The symptom you have is from a gasket behind the induction motor. We found that if too much stress was put on the assembly due to the vent pipe, it would open the gasket behind this motor. You may not have to even get a gasket.


It would involve removing the pvc pipe from the assembly ,pull motor, clean, run a bead of rtv silicone around gasket and snug back on. Test the pvc junction for stress. Sometimes the pipe does not line up well and guys will force it. This is what tweaks the gasket.


Good luck,



Customer: replied 8 years ago.
It very much looks to me like the PVC pipe is stressed due to sloppy installation. Thank you, XXXXX XXXXX a good answer.
Customer: replied 8 years ago.
I did not accept the "clogged pipe" theory. I accepted Billy's answer of stressed PVC bending the gasket.

I'm not sure if that means the website has paid Rick or Billy for the answer.