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Furnace condensate trap

Post Thu Oct 11, 2012 2:03 pm

Posts: 21
I have a Payne PG9MAB Furnace. Is there a way to check the condensate trap on a 90% furnace? I see a drain hose, a soft hose, and a 1/4 "pressure hose going in, and a vertical drain hose going out to the a/c drain pipe separated from the a/c evaporator with a trap.The drain hose, I can understand, but the soft hose and pressure hose is a mystery.

Post Wed Oct 17, 2012 7:36 pm
joe User avatar

Posts: 33
If your just wanting to see if the trap is clogged, you have to remove all the hoses from it, unscrew it, and take it to your sink. Run water through it (via your facet) and then flip it and run water through it the other way. Do this several times with good water pressure and any dirt should find it's way out.

I hope I answered your question- if not, please re explain it to me! Have a great one!

NorthAmericaHVAC.com
Joe

Post Thu Oct 18, 2012 12:40 pm

Posts: 21
Joe, I traced the drain tubes, one large tube comes from the bottom of the collector box(ribbed tube), one comes from bottom of inducer housing, (solid rubber), and small 1/4 i.d. tube from top of collector box. The large tubes are to drain condensate, and I beleive the small tube is a vent for the trap. Internally, the trap must have a reservoir that fills and a raised dam that empties, like a trap under a sink. I have read that the trap should be cleaned yearly of accumulated sediment.
I have received the igniter,flame sensor, 3 amp fuses from NA HVAC and will keep them near the furnace.
Thanks
Daryl

Post Thu Oct 18, 2012 2:02 pm
joe User avatar

Posts: 33
Yep, you got it- if you the cut trap in half, you would see the "dam like" resevoir. And yes, although 99.9% of home owners would never think of cleaning a condensate trap, it is good to do so! Once it cannot drain anymore, the water will back up into the collector box to the point that it will enter the inducer assembly and kill the air flow. This causes the air pressure switch to shut down the unit. At this point, most customers think that the air switch or inducer are bad, when in fact, it's only a clogged trap, or a crimped drain hose :).

Hope those parts sit around for awhile before you use them! Then again, as proactive as you are, you may be secretly desiring a failure at this point :D

NorthAmericaHVAC.com
Joe

Post Thu Oct 18, 2012 8:13 pm

Posts: 21
Joe,
I removed the trap and flushed it both ways in a laundry sink about 10 times with water and blowing both ways. Black crud came out until about the eighth time. I filled the inlet side and kept it level, reinstalled the trap, and it works fine. This unit is only two years old and the amount of black sediment shows that it should be cleaned yearly.

Thanks again,
Daryl

Post Thu Oct 18, 2012 9:02 pm
joe User avatar

Posts: 33
Yeah sounds like! I might also mention, if you have a way of doing so, you may check to see if the unit is burning cleanly. Is this a NAT or LP gas application? Sounds like a NAT gas since you have neighbors with similiar furnaces. LP is more prone to soot. It sounds a bit odd that you would have so much junk so soon, but of course, there are many factors to consider :)

NorthAmericaHVAC.com
Joe

Post Thu Oct 18, 2012 10:22 pm

Posts: 21
Joe,
It,s nat gas. The burners seem to be burning clean, nice blue flame, no yellow or other colors. Is there an adjustment for the flame, as it whooshes loud when it ignites.
Thanks

Post Fri Oct 19, 2012 1:25 pm
joe User avatar

Posts: 33
There is an adjustment on the gas valve that does allow you to adjust the gas pressure up or down. If you get it out of balance however, you will create sooting issues. They are set duirng installation to the proper setting (or should be). Typically, the loud "whoosh" you descibe is the nature of the beast with these furnaces and adjusting the gas pressure to lessen that can cause you other more serious problems.

Occasionally, on older furnaces, the inshot burners can get dirt in them and need to be cleaned. The dirt will cause the gas to somewhat build up before it reaches the ignitor and when it finally does light, you may get a good boom to it. I doubt this is what you are experience, but just some additional information.

NorthAmericaHVAC.com
Joe

Post Thu Nov 10, 2016 5:42 am

Posts: 18
Location: Madagascar

I dont have my unit anymore, but doesnt the override button on the AC Control Unit also work on the furnace?


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