Amana 90% Furnace Problem - kok328 help?

spitracer · 02-08-2010, 05:33 PM

Well I did it, I called a tech in from the place that installed the furnace 12 years ago....... he was somewhat puzzled. Finally he said he needed to go up on the roof because he really felt that the exhaust was somewhat blocked as the fire box was warmer than he felt it should be.

The exhaust and intake utilize a single pipe when it goes through the roof....a concentric fitting (sp). For those that don't know, this is a cone shaped pipe with the point sticking up with the exhaust exiting the center and the intake coming from the bottom side of the cone.

So he climbs up the roof 10/12 pitch 2 stories! He comes down and I ask him if he learned anything...He says yes. Apparently when they installed the furnace and the PVC runs they crossed them and the intake was sucking from the center and the exhaust was exiting from the intake air port

With the new inducer motor this was enough to trip the pressure switch.

So they will be fixing this issue shortly

and I suspect for free

I doubt that I would ever have figured this out!

One question does bother me has this mess up been allowing poor quality air to circulate in our house for the last 12 years?

Thanks for your help!

kok328 · 02-08-2010, 07:57 PM

Glad you were able to find the problem, I never would have been able to help you remotely and a 10/2, 2-story roof is out to the question for me. That is a really weird problem in that the system has been working fine until now. Sounds like the screw up on installation could have been somewhat fatal and yes, your makeup/combustion air may have been comprimised.
However, you now have some spare parts being that the old pressure switch was most likely not defective. The only advice I would provide you is that you invest in a CO2 detector for your home. It's cheap insurance just like a smoke detector. Keep in mind that CO2 dectors do have expriation dates.
I hope he gets it fixed ASAP, we're supposed to get dumped on with snow for the next 2 days and going onto the roof will be out of the question for him too.