Okay, please don't laugh. I've read the owner's manual and the Trane site a couple times now. It's totally gobbledygook to me. So here are my silly questions:

--The manual talks about upflow, upflow installed horizontally, and downflow. Our unit has the "grated" part on the bottom, which I think means that it's a downflow furnace. Anyone know whether that is right? Can someone please give me a simple explanation so I can understand what I have and which part of the manual applies?

--Assuming I have a downflow furnace, where exactly is the filter? Am I really going to have to call the local dealer to figure this out? (That's what the manual says.)

--Assuming I have an upflow furnace, which I doubt, I just can't find the two latches on the blower door where the filter supposedly it. (Sheesh--what's a blower door?) Can anyone help me find it?

--Do I really have to turn the power to the furnace off before changing the filter as the manual says? Do they mean at the electric panel? If I turn off the power and then turn it back on, will I have to do anything else to get the heater working? Will I need to light the furnace?

I do have an electronic air cleaner that sits on top of the furnace. And someone told me that that's the only filter I have. Could that be true?

I would really appreciate any help. As you can probably tell, I need a lot of help here. Thanks so much.

(((I do have an electronic air cleaner that sits on top of the furnace. And someone told me that that's the only filter I have. Could that be true?)))


Yes that is true. Sometimes there is a little metal mesh filter called a prefilter inside the electronic unit. It is very thin and used only to catch large pieces of dirt. Usually that is cleaned whenever the electronic air filter is cleaned.

What would happen if the electronic air cleaner has not been on while the heater and A/C have been running?

hvac1000,

Sorry about that. I hit the submit button without finishing my post.

Thanks for taking the time to answer my questions.

Yes the prefilter would still get dirty.

What is the filter model and where can I get the replacement (Trane XL80)