Need some help on this one guys.
Brand new Trane/Am.Standard TDC120 condensing furnace not firing.
It ran through the sequence; inducer-HSI-gas valve opens-no flame-shut down.
I've got 24 v coming from the board. Gas valve works. Bled the gas line.
I removed the cover to the combustion chamber and the sucker fired off. Ok blocked flue pipe right?
I removed all of the flue piping, both the intake and exhaust. Took all the external flue piping out of the equation. Put the cover to the chamber back on and the problem returned- no flame.
When it does fire (with chamber cover off) the flame looks good, nice blue tight flame, not dancing at all.