Help with Goodman HVAC drain line

[bluesky]

Hi, I have a dual zone HVAC system made by Goodman. The upstair handler is in the attic. I noticed that there are two drain lines side by side on one wall of the unit in the attic. One of the lines is plumbed to drain the condensate to the outside of the house. The other line is plumbed to drain directly into the emergency pan that the unit sits in. Of course, the emergency pan has a line that drains also to the outside of the house.
Since one of the drain lines from the unit drains directly into the emergency pan, this pan always has about 1/2 inch of water (since the drain line for the pan is raised up about this high.

Is the second drain line really suppose to drain into the emergency pan? Is there always supposed to be 1/2 of water in the emergency pan? Why did they not just run both drain lines to the outside world and leave the emergency pan for real emergencies? And why are there two drain lines on the unit, side by side?

Thank you very much for any insight.
Bluesky

[paul52446m]

Hi, I have a dual zone HVAC system made by Goodman. The upstair handler is in the attic. I noticed that there are two drain lines side by side on one wall of the unit in the attic. One of the lines is plumbed to drain the condensate to the outside of the house. The other line is plumbed to drain directly into the emergency pan that the unit sits in. Of course, the emergency pan has a line that drains also to the outside of the house.
Since one of the drain lines from the unit drains directly into the emergency pan, this pan always has about 1/2 inch of water (since the drain line for the pan is raised up about this high.

Is the second drain line really suppose to drain into the emergency pan? Is there always supposed to be 1/2 of water in the emergency pan? Why did they not just run both drain lines to the outside world and leave the emergency pan for real emergencies? And why are there two drain lines on the unit, side by side?

Thank you very much for any insight.
Bluesky

The reason for two drains is if one plugs up the other will still work. Thats why they don't both go into the same drain. The two drains in the coil are not the same height. They should be using the low one to go out side and the hi one can go into the pan. If it was done that way, and the main drain is not plug,
you should not get any water in the pan. If you unit freezes up than you could get water in the pan, but most of the time the pan will be dry.
Later Paul

[bluesky]

Hi Paul,
The two drains are side-by-side, or level with one another. Thus they look as if they would both be draining simultaneously, and this would cause the one on the right to of them to drain into the emergency pan and the one on the left to drain to the outside world.

I will be taking it apart to find if the drain to the outside world is clogged. If it is not, then was this a faulty installation? If the drain to the outside world is draining properly, there should never be any water in the emergency pan, right?

Tony

[HayZee518]

the rough spot in any drain line is if it isn't glued directly to the pan, it will rely on some type of locknut to hold the adapter or bulkhead fitting in the pan. since the locknut can't be flush with the pan bottom it will always be above the pan bottom by a certain amount.

[paul52446m]

Hi Paul,
The two drains are side-by-side, or level with one another. Thus they look as if they would both be draining simultaneously, and this would cause the one on the right to of them to drain into the emergency pan and the one on the left to drain to the outside world.

I will be taking it apart to find if the drain to the outside world is clogged. If it is not, then was this a faulty installation? If the drain to the outside world is draining properly, there should never be any water in the emergency pan, right?

Tony

In my 40 some years i have never seen two drains the same level, There is only about 1/4" difference between the two, and the main is the lower one. If they are the same height, you could always put a 3/4 by 1/2 bush in the one draining into the pan so it will be up 1/4". later paul

[bluesky]

HayZee,
Thanks for the comment. I do understand that you cannot get the drain line in the pan to be flush, and thus when water is dumped into the pan, there will be a static level of water there.

However, when things are working properly (i.e. - the main drain line is not clogged), is there always supposed to be water in the emergency pan? It seems like it would rust out eventually if this was the case.

Tony

[bluesky]

Paul,
I will go back and check how close they are in height. I was not paying close enough attention to probably notice a 1/4" height difference.

Thanks,
Tony

[bluesky]

OK, here is the latest.

Paul was correct in that one drain line output port on the handler is about 1/4 inch higher than the other. The lowest port drains to outside of the house, and the higher line is routed down to the emergency pan.

I siphoned out all of the water from the emergency pan so that I could better tell what was going on. Once the emergency pan was empty I opened the panel in the side of the panel where the drain ports are. Then I poured a 2 liters of water into the pan where the coils normally drip to see which line the water goes down.

The water had to go down the down the main drain line (lower port) because it did not come out the overflow port (higher port) and into the emergency pan.

So my question then is, how in the heck did the emergency pan get full of water? I did find a cold air leak in one of the lower corners of the handler, where some metal tape is not completely covering the corner. It is a hole that is roughly about 1/2-3/4 inch diameter and is blowing out a nice strong narrow stream of cold air onto the emergency pan, and the vertical edge of the pan sort of deflects the cold air in the space between the bottom of the handler and the emergency pan.

Do you think this cold stream of air could have been causing condensation in the emergency pan all summer long, enough to finally fill the pan up to 1/2" deep?

Thanks,
Tony

[paul52446m]

OK, here is the latest.

Paul was correct in that one drain line output port on the handler is about 1/4 inch higher than the other. The lowest port drains to outside of the house, and the higher line is routed down to the emergency pan.

I siphoned out all of the water from the emergency pan so that I could better tell what was going on. Once the emergency pan was empty I opened the panel in the side of the panel where the drain ports are. Then I poured a 2 liters of water into the pan where the coils normally drip to see which line the water goes down.

The water had to go down the down the main drain line (lower port) because it did not come out the overflow port (higher port) and into the emergency pan.

So my question then is, how in the heck did the emergency pan get full of water? I did find a cold air leak in one of the lower corners of the handler, where some metal tape is not completely covering the corner. It is a hole that is roughly about 1/2-3/4 inch diameter and is blowing out a nice strong narrow stream of cold air onto the emergency pan, and the vertical edge of the pan sort of deflects the cold air in the space between the bottom of the handler and the emergency pan.

Do you think this cold stream of air could have been causing condensation in the

Thanks,
Tony

emergency pan all summer long, enough to finally fill the pan up to 1/2" deep?

Hi Paul here. I don't think a small air leak would do that. The water had to come from the back up hi drain. When the humidity is hi maybe the main drain
wont drain fast enough. Does the main drain have a trap in it that can slow the water flow down?
When the humidity is hi, you have a lot of water running down the coil. So on a horz. coil the blower will blow some of the water past the drain pan.
Most units have a splash pan going out 8 to 10" beyond the pan at a 15 degree upward slope. One end of this pan hooks over into the coil drain pan.
The other end has a 1" hook up. This splash pan will catch the blow through
water and drain it back into the coil pan. Check to see if they put that splash pan in and make sure it is in place.
The same thing can happen if the coil get ice on it, that will also blow water
beyond the pans. Make sure your filter is clean and you have good air flow.
Later Paul

[bluesky]

The main drain does have a trap. But when I poured 2 liters of water into the coil pan, about as fast as I could from a 2-liter coke bottle, the main drain handled it well without any of if going down the backup drain.

My coil pan looks like it is a single pan, about ~30" long, sloping slightly upwards. The coil covers about 16-18" of the pan on the lower end of the slope. I don't see anything like a splash pan, but I would assume that the 12-14" of pan extending past the coil does essentially the same thing: captures blow-by water being blown off the coils.

When you say "make sure your filter is clean", you mean the filters in the return registers located in the walls and ceiling of the house, right? I change these about every month. Or is there some other filter in the air handler that you are talking about? The airflow seems pretty strong; whenever I try to remove the access panel to the coils, it wants to suck this panel shut, so I have to tug at this panel to get it off.

So the water in the emergency pan is still a mystery to me. Now that I have siphoned the pan dry, I will continue to watch it for what little summer we have left. Otherwise I might have to wait until next summer to see if it does it again.

Tony