Lennox

Last year, we made our concerns known to Jack Nelson Service Experts in Broken Arrow, OK, who installed the original system.  They came out and looked, said that there were a batch of bad switches in the lennox products, and they replaced the pressure switch.  Had a few more errors, they came out and did some calibration, then summer came around, the furnace was not needed, and seemed to resolve.
This winter, the whole thing starts again.  Always the same error.  It gets cold, the furnace tries to work, then error 276, calibration error.  Called Jack Nelson Service Experts again, they have always been very responsive.  The pressure switch was replaced, then a module was replaced, things just did not get better.  They talked with Keith Tanimoto from the Oklahoma Lennox Office, he is the "Field Technical Consultant".  He asked that induction motor pressures be checked, which Service Experts did.  Then he recommended checking the pressure switch calibration again, which was done.  Still the problem.  Tanimoto then wanted pre and post motor pressures checked, Service Experts came out again and got that information.  Then Tanimoto suggested re-checking and redoing part of the condensate system.  That was done, same problem (daily now).  Then we became frustrated and I asked that the system be fixed, or replaced.  Service Experts agreed, and empathized.  Tanimoto wanted more pressure checks.  Did that, problem persists.  Mr Tanimoto then finally drove from Oklahoma City to Tulsa and while on another trip, wanted to take a look at our system.  He did, and did all the pressure and induction tests again.  Said that the pressure switch seemed to be "just a bit out of calibration" and he was concerned that the vent stack was 4 inches, and should maybe be 3 inches.  So, his answer was to have the corporate office in Dallas send us a switch that had been "for sure calibrated" by their R&D folks, we would put that switch in, and at the same time down size the vent stack.  And that should fix the problem.  That was to happen last week.  This week, we still have the calibration errors, and a cold house.
When I asked Tanimoto what we would do if that did not work, his answer was " well, then we will be back to see what is really going on, then fix it the right way".  Jack Nelson Service has been out here probably 15-20 times all together, and we have reported this problem to them about 30 times.  The excuses have ranged from bad pressure switches, bad master board, bad module, vent stack issues, lennox had some bad parts, the list is endless...
Not trying to give anyone a hard time, but the service from Lennox, on their Brand New Machine, is elusive, indecisive, aversive and confounding.  We would just like the unit fixed, or replaced.