On 5/29/2011 9:01 AM, wrote:
On May 29, 2:25 am, wrote:
On May 29, 1:05 am, The Daring
wrote:





On 5/28/2011 8:17 PM, DerbyDad03 wrote:

I have a Conquest 90 Max gas furnace with central air.

I also have a bunch of questions:

1 - The internal coils have not been clean since it was installed 5
years ago, so I decided to take a look and see if they needed
cleaning. Problem is, I'm not sure how to access them.

I removed the screws from the panel where the condensate and
refrigerant pipes are, but as you can see from this picture, I can't
remove the panel because of the vent pipe.

http://imageshack.us/photo/my-images/62/furnacef.jpg/

If I could tilt the top or bottom of the panel outwards, I could
remove it, but the vent pipe prevents any significant tilting.

There is no other panel that I can remove. The other 3 sides that
surround the coils are a single piece which has the duct work on top
of it. The duct work would have to go up in order for the 3-sided
surround to come off.

How do I get to the coils?

2 - Through the limited opening, I can see into the coil area with a
flashlight. I see 2 tee-pee sets of coils and as far as I can tell
they are perfectly clean, at least on the surfaces that I can see with
the panel open as shown. Should I just close it up and forget about it
or are there areas I should check - assuming I can gain better access?

3 - When I removed the panel I saw 2 stickers, both of which raised
questions in my mind:

3.1 - One sticker has a picture of a "condensate drain trap" made from
a piece of flexible tubing attached to the drain output pipe. As you
can see from the picture, I don't have a trap. At the bottom of the
PVC pipe seen behind the gas line is the condensate pump.

The pump sends the condensate up a flexible tube and across the
ceiling to the utility sink.

I don't need a trap with that set up, do I?

3.2 - The other sticker says: "Coil is shipped with a low pressure (5
-10 psi) charge of dry nitrogen. Evacuate system before charging with
refrigerant."

Would the unit work (i.e. cool) if the system was not evacuated/
charged when it was installed?

I'm not saying that it wasn't evacuated/charged because I don't
remember if the installer did it or not, so I'm just curious.

Thanks!

Are you sure you can't get the PVC vent loose and swing it aside?
Me and my bud I do AC work with never install a 3/4 PVC drain without
a union so we can service the drain if it clogs up. You can cut the
3/4 drain line and install a coupling without glue so you can get it
loose. I always use unions anyway. With the 3/4 drain out of the way,
you could easily remove the cover. Big box stores have the unions.

http://www.grainger.com/Grainger/Union-1WKD7

TDD

@TDD:

That vent pipe is for the flue gasses from the burner in that high
efficiency direct vent furnace... I wouldn't cut into that for any
reason EVER, as if you don't glue it up perfectly when you put
it back you will have issues with carbon monoxide leaking into
your home from the exhaust products during heating season...

While I would not cut the vent pipe unless it was really
necessary, the notion that you can't do it "EVER" because
it's dangerous is pure nonsense. It's just glued together
using regular PVC cement and if you can glue a piece of PVC,
it's no big deal. IF you think that is high risk, explain how all
the furnaces, hot water heaters, etc, prior to high efficiency
used simple galvanized sheet metal pipe that just got shoved
together and secured with sheet metal screws. The seal
there was far worse than what you get today with PVC pipe.

The older systems that you could simply slap together as you described
were natural draft. High efficiency designs use induced draft and the
flue is pressurized because of it.



The better solution here is to have the OP cut the sheet metal
panel which can not clear the obstacles and obtain a piece of
flat stock which he could install so he could screw it back into
one piece when he is closing the coil compartment on the
main trunk duct back up again... The joint the OP cuts in the
cover panel and the screw heads can be sealed up with foil
duct sealing tape...

~~ Evan- Hide quoted text -


I'd like to know how he's going to cut that piece of sheet metal
when the access is so limited. For sure I'd cut the exhaust
pipe before I did that. I'd also check to see what the exhaust
is or isn't connected to inside the furnace. There is a small
chance it could be disconnected from inside.

But, if the coils appear clean, I'd just put it back together and
save a lot of trouble. The real problem here is that the eqpt
manufacturers typically don't provide a means to clean the
coils. Nor do installers take that into account when doing
the install. On the other hand, if you have a decent filter,
I've seen systems that went 25 years and the coils were
still fine.