My non-expert understanding of newer, higher efficient furnaces is that water as a by product is produced at a greater rate than older, lower efficient furnaces.

For example, I have an American Standard duo-speed 80 and also didn't grasp the amount of water it would produce when running (13 gallons/minute I think it is) over our previous furnace. Long story short, just last month a SS chimney liner was inserted for the furnace water effluent and the flue pipe size adjusted.

If the sump pump is allowed for a condensing furnace, it sure does seem as a valuable tool. PVC is often used nowadays as a conduit. Sorry, I don't know how a condensing furnace differs from my gas furnace so please ask your installer.

More knowledgeable HVAC people should be by shortly.

It looks like the drain can't handle the volume of water from the new furnace. Do you know if this drain is connected to a sewer or does it drain into the ground?

The best solution would be to install a condensate pump. You can run a flexible tube over to your sump pump pit. Below is a link to pump I have on my furnaces.

Here is a link that might be useful: DiversiTech condensate pump

Yeah, thanks. It looks like I will need a condensate pump. I'm annoyed that was not included in the original quote. And I suppose I can expect even more water in the Summer, from the the air conditioning, correct?

So, let me ask -- do these pumps always plug into the wall, or can they be connected to the furnace, and draw power there? It sounds like I do want one that will wire into the furnace to shut it down in the event of a pump failure. My basement is finished, and I do not need any more water on the floor.

The pump runs off 120V. It has a 24V output which is used to shut down the furnace if it fails.

I don't seen the furnace shut off switch. Is it on the other side? I would reconfigure the switch so that it is near the pump and change it to a combination switch and outlet. This is where the pump is where you plug in the pump. The switch only shuts down the furnace. The pump is wired back to the control board in case of a failure.

Since you have a nearby finished area I would also install an overflow detector on the output of the coil. This will also shut down the furnace if the drain line is clogged.

Since you will be redoing the drain line I recommend you install a clear drain trap. EZtrap makes a nice product. It is a clear tube with snap openings. It comes with a cleaning brush.

When my similar Trane furnace was installed, the water ran onto the floor. The installer found a tee on the clear drain line inside the unit that was never connected. Removal of the lower front panel was necessary for access. Installer accused me of disconnecting the tee. I had never touched that panel. I think the tee brought together the AC and furnace condensate lines.

Have you called installing dealer about this issue and what was his reply?

Not normal or acceptable!

This is your starting point before a condensate pump s installed.

Your drain is not stopped up? Should be checked but of course just speculating. Water should not be on floor.

IMO

An old AC man. This has been an old problem I see, but for anyone that might hit this sight I offer the following. From the picture the drain from the furnace condenser (high efficiency furnace) at the top drops down to the drain hole. BUT, just before the drain hole is the drain from the bottom of the furnace which must be a drain for coils or what ever. The furnace fan is pulling a negative pressure on this drain pipe and pulls water into the bottom of the unit. I assume it is leaking out of the lower portion of the unit onto the floor. I do not think the flow is too much for the drain. A portion of the drain water is being sucked into this lower section and then is draining out of the lower section onto the floor

The solution is to break the two drain pipes apart and have each drain drop into the floor drain. I think this will solve the problem. No condensate pump is required.