My Comfortmaker model is N9MSE0601714A1, manufacture date Feb 2013. We have been experiencing problems with the Comformaker since second year it was in service. Last winter, Feb 2018, the servicing company asked us to leave the unit door open. It has been working until they did a service on Nov 8. Now it starts a few minutes and then shuts down. The light flashes 3 time and the technician first thought it could be a bad pressure switcher. He replaced the pressure switcher last Friday(11/16) and it didn't work. So he took back the new pressure switcher. Then he told us there is a problem with condensation which causes the pressure switcher to shut down. He suggest installing some kind of T on the unit pipe to diverge the water to the drainage. I also had another company look at it, first he rewire the inducer and it didn't fix the problem. Then he said the circuit board is bad casuing the pressure switcher to stop. I couldn't decide to go ahead with installing the T or replacing the circuit board. Has anyone fixed similar issue ? Thanks in advance.

Have a Lennox G23 series gas furnace. Found another thread with exact issues I was having: 1) Furnace lights normally 2) Heater blower does not engage after the 45 second window 3) Furnace shuts off due to over-temp sensor triggering If the fan is set to "On" instead of "Auto", the furnace runs fine: If I have it set to "On" before engaging Heat, it'll shut the blower off for a few seconds, engage the ignition, then re-engage the blower Otherwise, if it's "Auto", I can still light the flame and just turn on blower to "On" before the over-temp kicks in. Based on that old thread, it looked like a Blower Controller needed replacing (BCC3 in my case), which I did, however it did not resolve the issue. So, I decided to step through the diagnostic test in the manual with a multimeter. Here is where I'm confused with the results: 1) Manual says if the flame is on, then after 45 seconds there should be 120VAC to the Heater blower -(N)eutral and (H)eat should have 120VAC - they did 2) If blower was not running, then I should check for 24VAC between "T" and "V" (Valve sensor and Common coming from Ignition Control) - they did So, both these results indicated I need to check the blower and blower wiring. Here's what I got when doing some further testing: 1) When just blower "On" without flame, I get 120V between N and "A" (Blower cooling tap - Black wire) - basically engaging blower at full speed, but also 167V between N and "H" (Heater - Red wire) 2) When flame is on but Auto blower doesn't engage, I get the 120V between N-H after 45 seconds 3) Turn Blower "On" with flame, I get 120V between N-A, and again get a high 167V between N-H 4) I then turn blower back onto "Auto" with flame lit, N-H stay at 167V, but N-A (which should disengage completely) stay at 120V 5) With flame turned off and blower going into the 90 second cooldown, N-H drop to 120V, N-A drops to 80VAC 6) In running the test a few times, it seems that occasionally the "Auto" will succeed in getting the blower running through H at 120VAC...but it lags for a few seconds after hearing the relay click at the 45 second mark. N-A do have the 80VAC on them though. [B]In summary:[/B] Blower does not engage with heat; Controller Board replacement did not resolve. Manually engaging blower prevents over-temp, but voltages are seemingly off. Whenever the blower is on, N-A seems to be at 65-75% the voltage of N-H. If I force it on, I get 120 at A and 167 at H; if H manages to do its thing at 120V, A still gets 80V. Given that my BCC board seems to be engaging at the right times, is this a case of the blower motor having a short/issue?