My background is electrical control, automation, and networks - the drive guy on commercial and industrial jobs.
This is not the usual flame failure problem.
I installed a G71MPP-60-090. Met all the specs for venting, condensate trap, return and supply air. Set the control board board for a single stage thermostat and started-up.
It ran perfectly for the first day as I buttoned up misc. things.
Day 2, it started to have flame failure -Error Code 273. Day 3 no successful starts - again flame failure.
According to the flow chart when calling for heat, observation of the flame and timing, it goes through start-up calibrations, ignites and is statisfied there is a flame. The flame is robust.
I think it also properly goes through the stabilzation delay but not sure. I think it flames-out when it goes to low firing rate.
I've turned all other gas using appliances to possibly mimic day 1 - no help. I toggle the dip switch 1, back and forth to recognize a single stage thermostat. I checked the vents for obstruct. Today the outside temperature and wind are almost like day 1. I'm still having flame failure.
I'd appreciate and suggestions.