honeywell gas valve issue

[Tommy1010]

Lennox 3 ton rooftop package... LP gas heat
honeywell VR8245M2530 smartvalve
Tries igniting but valve wont open. Gas was verified to be present at inlet of valve.
All safetys are closed and 24v is at the valve (between PV and PV/MV) ... but no gas...
what the hell?

[keef]

may sound stupid but had a 5ton york last weekend had very much the same issue... the flame rod was causing the issue

[socotech]

Yea. Sounds like you need to clean your flame rod.

[hands]

What is the inlet gas pressure to the gas valve. If it's higher than the max rating, the valve most likely won't open. The regulator may be letting the gas pressure get too high over time when the burner is off. Try relieving the pressure between the regulator and the valve then see if it lights.

[rundawg]

Lennox 3 ton rooftop package... LP gas heat
honeywell VR8245M2530 smartvalve
Tries igniting but valve wont open. Gas was verified to be present at inlet of valve.
All safetys are closed and 24v is at the valve (between PV and PV/MV) ... but no gas...

Tommy, this is NOT a SmartValve.

The SmartValves series start with SV9500 model numbers.

Now to your question:

I'm guessing you have something like a S8610U control module for this unit?

Assuming the inlet gas pressure is O.K., and the control module is sending 24v to the PV and PV/MV terminals on the gas valve, but the pilot portion of the valve is not opening, you need to replace the gas valve.

The flame sensor does not come into play until the pilot is lit.