I have a three year old bryant 340aav furnace. It starts and the burner lights. It runs for about 15-20 minutes and then shuts down. There is a red code light that flashes an error of 13 or 33.

Read the label on the back side of the blower motor access door to find out what the blink/flash code means then refer to the link below for part locations.

http://www.bobsheating.com/PDF/Plus-90i-90t-90-owners-man.pdf

Thanks anyway. I did that already and am still stuck. It is either a code 31 or 13. Anything else you could recommend?

Yes post the meanings for the codes you mentioned for your specific furnace.

Code 31 pressure switch did not close or reopen. I turned funace off and then on. It starts and runs and then shuts off. There are three rapid flashes followed by one long red flash.

You might take off the hose connection and make sure it is clear with no restrictions or cracks/damage

Which hose connection? Thanks.

The ones that go to the switch

Can you please give me a little more detail on this? Thanks.

The pressure switch is connected by a small hose. This hose if defective or plugged up can cause problems. If you cannot find the hose I do not know what else to say. Sorry but you might be better getting ON SITE service for your unit.

I found the hose it has a pink tag on it and the switch. I disconected it from the switch and plate that runs into the furnace. The tube is clear and I can blow through it. When I disconected it from the side that goes into the furnace a steady flow of water came out. I have my furnace in the upright position.

I found the pressure switch and hose. The hose is clear and in good condition. When I removed it from both ends a little stream of water backflowed into unit from the black plate mounted to the furnace not the switch end. Is that water normal?

Have you tried to start the furnace since you cleared the tube?

Yes. Same issue. I just removed the swith and I gently tapped it on my leg. I am going to hook that up again and try it?

Still nothing. Same thing time and time again. Runs for 10-15 minutes, then flame goes out and blower continues to run. At leat its only going to be 15 degrees tonight. Called several heating and cooling places and I am awaiting a return call.

There should not be any water coming out of pressure switch hose(where hose connects to heat exchanger). This is a sign that the drain system on your furnace is clogged. Disconnect and clean all drain hoses and all ports that drain hoses hook to. As your furnace runs, it condensates and the condensate needs to drain off or the water will just back up in the heat exchanger and or exhaust fan causing the pressure switch to open during operation. The reason it starts back up is because the water is slowly draining(not fast enough due to a partial clogg somewhere in the drain system) So when you shut the heater off, the water slowly drains, then when furnace is kicked back on, the water is building up faster than it can drain, so the pressure switch opens, and the furnace shuts down. Just clean all rubber hoses and all ports and traps that they may hook to. The water has to drain to somewhere, so follow the drain pipe on the outside of the furnace and make sure is it clear of cloggs and can drain easily. Hope this helps.