HELP! Gas Valve Issue?

NinjaGuy50

After using online troubleshooting, I may have found the issue but am unsure how to fix.
Furnace ran yesterday morning with no issues. After I went to work, when furnace was supposed to kick on for family, it didn't. The exhaust fan runs and the ignightor lights (electronic, not pilot light) fine but when it's time to call for propane, it doesn't fire. It runs the cycle twice and then shuts off. Furnace is about 20 years old (maybe but not sure) and the control board was replaced probably 5 years ago. Control board has 1 red light that is steady on when running/ok but now has 1 slow blink which my troubleshooting list shows as exhaust pressure switch, which is fine.
As I said before, ran fine yesterday morning but then went to the next cycle of the program on the thermostat and didn't run for about 6 hours while no one was home.
Any thoughts of things I can try myself before calling for repair (which I can't afford)?
Thanks!

EdTheHeaterMan

The pressure switch has a hose on it that goes to the fan. remove the hose, there may be clips that hold the hose tight. You can use plyers to release the clips and pull on the hose off the stub. Once the hose is off you can blow air thru to clear it. Then take a paperclip and bend the end to probe in the stub on the fan to clear any blockage. (don't probe the switch, you could damage it.

Replace the tube and see if it works.

Also, the blocked vent switch is to let you know the vent is blocked. look in the vent pipe to see if there are any obstructions.

NinjaGuy50

Both are fine. I've replaced the pressure switch in the past and the igniter wouldn't light when that didn't work. It seems like the furnace isn't getting gas.

STEAM DOCTOR

Is gas valve getting power? There is blinking light that indicates something is wrong with the pressure switch. Maybe the pressure  switch is bad. Maybe the control is bad...........Does no sound like a gas problem. 

JUGHNE

How full is your LP tank?

SuperTech

NinjaGuy50 said:

Both are fine. I've replaced the pressure switch in the past and the igniter wouldn't light when that didn't work. It seems like the furnace isn't getting gas.

The blinking LED showing a fault code is indicating that both are not fine. The code doesn't mean that the switch is bad and needs replacement. Its indicating that the switch is doing its job as a safety device,  preventing the furnace from operating in a potentially dangerous manner, such as a blocked flue pipe. I think you are in over your head and need a pro, no more part swapping.

DZoro

Need to put a magnahelic on to see what's actually happening. What furnace do you have?

retiredguy

I used to have an American Standard 90+ where the condensate water trap would clog up with gunk. The fix was to remove the drain tubing and flush out that trap. I used a piece of tubing about 2 feet long the same size as the inlet tubing, manually filled with water, then using your breath to push the water out of the tubing to flush the trap. You can also remove the trap for cleaning. Also, check all the condensate hoses that drain water from the furnace to make sure they are not blocked.

Seabee5701

If you get signal for ignitor to turn on its not the inducer or air proving switch. The ignitor needs replaced....