Air Conditioning - secondary drain

just had an upflow condensing furnace and a/c coil installed. due to some limitiations a pan couldn't be installed under the whole setup. but now the contractor is telling me that it would be worthless to install a condensate switch on the a/c coil pan because if the drain were to clog it would just overflow out of the furnace. but it seems to me that the furnace should be air tight so that the fumes don't come out and if it's air tight then why would the condensate come out of it should the drain clog? the other question is it seems like some furnaces have some type of safety that if the condensate backs up that it will shut off, intended for the combustion condensate. could this be used for the a/c condensate filling it up? would this happen even if only the fan in the furnace is running? the coil is above the furnace. Thanks for anyones input.

Is there a secondary drain port on your evaporator coil?
I would at least pipe that to a small pan with a float switch.
You don't want water running down the inside of your furnace. Circuit boards and motors are not cheap.

Did this installation get an city inspection?
The city inspector might have some good recommendations.

Yes I would think that if there was a permit pulled there would be an auxiliary pan. I am not sure what the limitations were but you have to have some way to stop the unit when the drain backs up, and it will back up. There is a new safety switch that goes in the drain exit from the pan that will open when the drain line starts to run slow that can help you in this situation but I would still need to hear what the "limitations" where.

No permit, no inspection. That would make this a lot easier since it wouldn't be approved without somehow fixing it. There is a secondary drain connection on the a/c coil which could be an option. But the contractors POV is that none of this matters because if the primary drain clogs somewhere downstream then the condensate will now come out of the furnace since the pipe also connects to the furnace and the furnace is lower then the a/c coil.

..........................................

Is there a secondary drain port on your evaporator coil?
I would at least pipe that to a small pan with a float switch.
You don't want water running down the inside of your furnace. Circuit boards and motors are not cheap.

Deff a need if in attic ..no reason one should not be used in any location................

Did this installation get an city inspection?
The city inspector might have some good recommendations.

Once again a secondary drain a +++++++++
Or a over flow switch ina secondary pan ...................

No permit, no inspection. That would make this a lot easier since it wouldn't be approved without somehow fixing it. There is a secondary drain connection on the a/c coil which could be an option. But the contractors POV is that none of this matters because if the primary drain clogs somewhere downstream then the condensate will now come out of the furnace since the pipe also connects to the furnace and the furnace is lower then the a/c coil.



Saved a few $$$ huh ??

....................................................................................

No permit, no inspection. That would make this a lot easier since it wouldn't be approved without somehow fixing it. There is a secondary drain connection on the a/c coil which could be an option. But the contractors POV is that none of this matters because if the primary drain clogs somewhere downstream then the condensate will now come out of the furnace since the pipe also connects to the furnace and the furnace is lower then the a/c coil.

Make an opening on the primary drain pipe (reverse T)at somepoint lower than the furnace. SO, if the primary drain clogged downstream, it will overflow out from the reverse T which you can put a small pan under it with a switch.

What about an EZ-Trap? I would think that would solve the problem.