Disconnect the low speed connection of the inducer motor, wire high and low fire signal to the high speed connection of the inducer . So what ever the call inducer runs in high speed ?.
S9X2's different sizes all installed horizontally with very short runs to concentric intake/exhaust. Units are failing on rollout switch trip (manual switch E04). Problem only happens in low fire. Checked hx vacuum in low fire and got -0.9 IWC. Don't know what it should be, but it definitely should be higher than that. Pressure switch that runs to condensate drain is listed as -1.0 IWC, and unit did fail once and throw that code (E09). Trane came out and replaced a few items on the first unit with no success, then finally fixed it by "adjusting the board to increase inducer speed in low fire." Looks like they will have to come do it again. Frustrating part is the issue takes about 20 minutes of running in low fire to present itself. I feel like with 2 out of the five units in this new building showing the failure after one month of service it may occur in the other three as well.
Question: Has anyone else run into this and is their a bulletin on how to speed up the inducer without going through Trane?
"If you've eliminated all other possibilities whatever remains must be the truth."
Disconnect the low speed connection of the inducer motor, wire high and low fire signal to the high speed connection of the inducer . So what ever the call inducer runs in high speed ?.
Double check the flue runs, make sure they meet minimum requirements, I would jump w1 and w2 together, get the installation company involved.
I'm not young enough, to know everything...
"Disconnect the low speed connection of the inducer motor, wire high and low fire signal to the high speed connection of the inducer . So what ever the call inducer runs in high speed ?."
I would never alter a furnace like that, too much liability for me. I wouldn't want to do what Trane did to the first one without some literature from the manufacturer to back it up.
"Double check the flue runs, make sure they meet minimum requirements, I would jump w1 and w2 together, get the installation company involved."
My company installed it, LOL. The lead quit right about the time I started. The install is not even close to perfect, but it doesn't have any issues that should cause this. Flue looks good and install has been gone over with a fine tooth comb by two Trane techs, trying to find a way to blame the install. Consensus was inadequate draft on low fire from everyone involved and speeding up the inducer was the solution. These units are too smart to jump w1 and w2, I think they use other inputs as well to decide what level they will heat on.
"If you've eliminated all other possibilities whatever remains must be the truth."
Have you pulled one of the draft inducer assembly’s yet? Possible bad seal on chamber or factory debris? Just throwing out some ideas, as you’ve exhausted most of the obvious things.
I'm not young enough, to know everything...
Is condensate getting backed up in the combustion hx and associated parts? I would check the pitch of the intake/exhaust and drainage. How is the airflow through the air-side of the system?
I appreciate the ideas, but troubleshooting is complete, the issue has been found and it has already been corrected on one unit. I just wanted to know if it was something I could perform myself, or something Trane is keeping to themselves.
"If you've eliminated all other possibilities whatever remains must be the truth."
I am not aware of any "Service Bulletin's" on this issue, but there may a "Confidential Service Alert" that I am not aware of.
Can't you contact the Trane Rep who came out and ask what he did that is an acceptable practice for other units you come across?
If you find out what he did, please post the procedure in the "PRO" forum.
Instead of learning the tricks of the trade, learn the trade.
Information doesn't flow that freely around here. I didn't even know the first unit had been fixed until I was sent out to look at the second one and called in the diagnosis that it was doing the same thing. My boss told me they went into the board and did something to speed it up. I asked how they did that since it looks like a simple two-speed shaded pole motor and he said he did not know, just that is what they said. I asked the dispatcher to see what they would say and do not expect a reply. Like I said communication is crap around here.
"If you've eliminated all other possibilities whatever remains must be the truth."
Did they perhaps reduce from a 3in to 2in horizontally?
Dig into the install manual and look close at the vent instructions. A couple things come to mind. One is they always say don't mix sizes. I wouldn't think that would include the termination but it may. But the other part where that concentric could play a part is there was an issue with not enough restriction on the intake especially on single pipe systems. It was required to add several feet of pipe and at least 2 90's. That sounds like more restriction than you have with the 3" concentric & 7' of pipe.
"If you've eliminated all other possibilities whatever remains must be the truth."
opening of concentric installed into the direction of the prevailing winds? I can't recall an issue like this in the past. just throwing an idea out there
there has to be some sort of Altitude adjustement they messed with