Furnace not going into main flame

Timco

Sounds like a classic flame sensor issue. Clean in with steel wool. May need a new one.

T

dalton

Furnace not going into main flame

Hey guys and girls,troubleshooting a luxaire combination heat/cool unit. Calling for heat from t-stat, inducer draft/vent motor comes on, module energizes pilot valve same time ignitor clicks away but i'm not getting main flame. Observing the pilot tube i notice the flame doesn't go all the way across to the sensor. When it did, once, main flame right away, but shut right back down and i didn't get main flame again. I'm wondering if its the pilot tube orifices some might be clog or there's a problem with the gas valve. (System keeps retrying until lockout)

Blackoakbob

I've had this same problem....

> Hey guys and girls,troubleshooting a luxaire

> combination heat/cool unit. Calling for heat from

> t-stat, inducer draft/vent motor comes on, module

> energizes pilot valve same time ignitor clicks

> away but i'm not getting main flame. Observing

> the pilot tube i notice the flame doesn't go all

> the way across to the sensor. When it did, once,

> main flame right away, but shut right back down

> and i didn't get main flame again. I'm wondering

> if its the pilot tube orifices some might be clog

> or there's a problem with the gas valve. (System

> keeps retrying until lockout)

Blackoakbob

I've had this same problem....

It was on a new install. The electrician had switched the black and white wires in the conduit junction box, between the breaker panel and the furnace, causing the circuitboard to short cycle. Turn off the power, take each connection apart and follow it all the way back to the breaker panel. Somewhere in the installation manual there will be a reference to this. If this is not the problem a gas pressure check might be next on the truobleshooting ladder to success. Best Regards,

Arthur

Senors not picking up flame

I had this problem on some lennoxs in a hydroponic glasshouse. the fumes from the hydroponics had got to the burners and the wings on the inshot burners had a lot of rust on them preventing the flame from shooting right across to far side were the sensor was,
solution was to remove the burners and clean the slot in the wings with a wire brush and a screwdriver blade, and to make sure they were in line for the flame to light right across.
The Lenox's were rotting away from the fumes. lesson Never ever install heaters inside were the fumes from the hydroponics can get at the heaters.