Premature Burner Shut-Off - Rheem Gas Furnace RGTA-07EMAES

[All2kool]

I am looking for some advice on my Rheem Gas Furnace RGTA-07EMAES, S/N EJ5D702F150100415. If I read the S/N correctly, the unit was made in the 15th week of 2001.

It recently starting shutting off the burner mid-cycle but will attempt to re-light. Sometimes it re-lights, sometimes it does not. After 3 failed attempts to re-light, the system goes into 'safe mode' and won't attempt to reignite for an hour unless I reset the power from the breaker box. The LED error code of 1 flash indicates 'ignition failure' after these 3 failed attempts. This is the only error code displayed.

I replaced the Flame Sensor (was careful and did not touch it) with a new Rheem part but this hasn't solved the issue. The original Honeywell Gas Valve was also replaced with a direct replacement Gas Valve 60-103901-01 as it was making a horrible clicking/clanking noise as the burner would pulse and 'flame out' like a jet engine. There is no rhyme or reason to this intermittent function.

The Honeywell thermostat is not the issue as it does begin and end the heat cycle as designed when the heat cycle has not been interrupted.

I've had two techs here in the last month prior to replacing the Flame Sensor and Gas Valve but the problem could not be recreated in their presence so nothing was done. The first tech noted a slight burning on one of the resistors. I pointed it out to the 2nd tech and he mentioned he'd seen that before. I've included a link to a photo but the flash from the camera somewhat makes it less noticeable. It's the 2nd blue resistor from the top.



Am I correct in assuming that I really should replace the Circuit Board to resolve my issue?

Thanks in advance for any help.

[Admin]

It could be the control board, but a pressure switch tripping open quickly can cause this too.

I would rule out any venting issues, like slope problems that allow water to accumulate inside the venting, or drain line issues like a dirty drain line that cause water to backup into the furnace.  Also make sure the vents are clear outside and not covered by ice or snow.  Sometimes the intake will suck in the flue gas from another appliance and start to ice over.

I use the audible resistance multimeter setting to test the pressure switch while I have it bypassed to see if it's opening and closing quickly.