Is it right is it wrong??????

90% furnace in the attic other than the primary drain being stopped up is the piping correct or wrong.

Ok Charlie I’ll bite as I respect your knowledge and don’t mind being occasionally schooled. With the exhaust under pressure I don’t think the condensate drain should be connected in any direct way to the air distribution ductwork. Same comment for the condensate drain attached to the vent stack…sewer gas can be drawn into the air distribution system.

I have some opinions but not trying to school anyone I honestly have not seen this particular set up. I do try to reason out something that I have never seen before.

The piping configuration also prevents adequate working clearance…

Main drain pan discharge into the secondary pan, missing a plug and trap is installed in the wrong location. Connection to main vent may not be proper either.

Ok let me say what I see and what I don’t see. In my area the primary drain is allowed to connect to the sewer vent stack if there is a wet trap in use and there is but it is in the wrong place it should be installed after the furnace and the A-coil drain connection. On this unit it was after the A-coil connection and before the furnace condensate connection. The primary drain line was actually stopped up and water was draining into the safety pan, the secondary drain line was exiting the attic by the front porch entry door. As to why they connected a drain line on the exhaust flue pipe I can not say its right or wrong I just have never seen it installed that way. Normally the flue drains back into the housing of the blower and drains from the housing thru a rubber hose

Is that unbonded CSST piping that feeds it?

Have you ever seen it any other way?:wink:

I’ve seen it on occasions; on some HE WH also.

Thanks Marcel I just never seen it connected like that I guess a first time for every thing:D

lol, I have not.

I’ve** never** seen CSST piping used where it was bonded. :cool:

The solid metal pipe should be bonded and having the CSST piping connected to it makes it bonded.

That is first year HI stuff:p

More info at:

Dead wrong. The furnace has a drain for condensation created by the exhaust.
The exhaust vent must have grade draining toward the furnace. And the 90% furnace has a drain line inside just below the inducer fan motor. And must be piped out of its own drain line. If that is in North Carolina it never got inspected. That is a requirement here not sure if it is where you are from if not it should be. It is the cheapest insurance money can buy. No matter where you are the manufacturer would never have allowed that. You might check the manufacturers installation instructions. You can google the model number and you should be as to pull it up. Hvac licensed contractor with 25 years experience.