Thread: Bryant 90+ Efficeincy condensate drain problem

My Bryant 90+ Eff. furnace (350 MAV) continues to give me error code 31. Error 31 can be a lot of things. The way I fix it is to remove the hose that goes to the pressure switch and allow the water that has accumulated drain out. The water that drains out is usually about 1 cup. I am trying to figure out why water keeps accumulating here because it should be draining down to the condensate pump. Any Suggestions?

My apologies if this question is in the wrong area of the forum. I am new and not familiar with the structure yet.

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The problem could be a number of things all related to one source, the water. There are a number of things you should check for: Proper vent sizing and condensate pitch, Vent restriction, Defective inducer motor or start capacitor, Defective pressure switch or connections, Low inducer voltage, obstructed pressure tubing.
However, the tubing up to the pressure switch should NEVER fill up with water under normal functioning conditions. The pressure switch is there specifically to shut the unit down if there is a venting problem. You need to figure out where the water is coming from. Down from the vent pipe through the inducer or up through the secondary heat exchanger tubing. Your vent pipe could be taking in water or the condensate isn't draining away. Either way the water is the controlling factor at this point. Figure that out and the other problems will reveal themselves.
As a note, this is a home inspector board. You would probably be better off posing this quesiton on hvac talk or jlconline for specific answers.
Good luck.

Is this a new installation or did it use to work ok and then start having this problem?

Markus,

Thanks for the response. I suspect the drain system is the problem. Prior to posting this problem yesterday I blew air through the hose that connects to the pressure switch ( I disconnected the hose from the pressure switch and blew air through the tube; I do not know the name of the component on the other side of the tube. I have not heard any gurgling like water was being blocked from draining. I have been checking this system a couple of times per day. I appreciate you taking the time to share your thoughts with me. I will try to find the HVAC section and post there next time.



James: This is a system that has worked for many years. I do remember a service call that we placed after having the system a couple of years. The tech came out and blew air through a hose and charged us over $100. I know people have to make a living but I vowed to be a little bit more curious before calling for service again.

There appears to be a moisture collector in the fan compartment of this furnace. This could be causing a problem with getting rid of moisture crated by the unit. Big shot in the dark here!

Originally Posted by Mark Nordwall

My Bryant 90+ Eff. furnace (350 MAV) continues to give me error code 31. Error 31 can be a lot of things. The way I fix it is to remove the hose that goes to the pressure switch and allow the water that has accumulated drain out. The water that drains out is usually about 1 cup. I am trying to figure out why water keeps accumulating here because it should be draining down to the condensate pump. Any Suggestions?

My apologies if this question is in the wrong area of the forum. I am new and not familiar with the structure yet.

Mark, one thing you may want to check, is the condensate trap assembly made by the manufacture, is on the same side of the unit as the exhaust flue. This requirement is in the installation instructions but is often over looked by the installer. There is a retrofit kit that can be installed instead of moving the flue or trap. I have attached a picture of a furnace with the flue on the wrong side and a picture of the same furnace with the kit installed.

If condensate has to travel through the fan housing it can be picked up by the fan and blown into pressure sense lines.

James/Vern:

Thanks for your suggestions. It looks like my condensate trap/flue assembly is on the same side as the exhaust flue.

Ever since I forcibly blew air through the pressure switch hose I have had no accumulation of water in my system. I did pull the drain hose and saw some nasty muck that had accumulated in it over the years. I will plan on replacing that hose once the weather turns warmer in May or so.

Thanks to all of you that took time out of your day to help somebody out!