I have an intertherm propane furnace, new in 2006 we just turned propane back on for the year, and it won't light. The red light is blinking 2 times & indicates "pressure switch open with inducer on" however I have no idea what that means or how to troubleshoot to fix. It hums like always before it kicks on, but there is no flame. Propane is on, ignition switch is on... any ideas? Please Thank u

Your pressure switch is more than likely stuck close. Your system will not fire with this condition. It is a safety condition to prevent the unit from operating with the inducer not running and the pressure switch jumped/closed. Turn the system off and pull on wire to the switch. Start the unit and wait until the inducer starts. Give it a few seconds and attach the wire you removed. If the system fires then you will probably be replacing the pressure switch.

There are two wires, pull both?

Negative. Pull only one. Either one you want.

Turned off power, unplugged 1, turned power back on. Inducer motor came on, before plugged in, 2 lights flashed, plugged back in, 2 lights still flashing. Any other thoughts? P.S. Thanks for your help, single mom, xmas time. P.S.S Inducer motor is hot

Also have thermostat set to heat, auto fan, and 80 (which should kick the heat on)

Inducer could be failing but that wouldn't explain why your system is telling you that the switch is closed. Did you wait about 10 seconds before plugging the wire back in?

Its telling me the pressure switch is open with inducer on?? Same thing as switch is closed?

Clear plastic tube on bottom left side was very dirty. Removed & it had water in it!? Possible problem

Very much a problem. If the tube has water in it then you are getting moisture backing up in the system. Is this a high efficiency unit?

Can you hear water in the inducer? If so,I'd say the drain is plugged and not letting the water out of the inducer,thus it won't pull the pressure swith closed.

Yeah

I got the water out of the "j" tube & replaced. Anything further I should do?

Does the plastic tube connect to the inducer?

Remove the end of the tube that connects to the inducer,and blow through it. Does it feel plugged?

The tube runs from the bottom of furnace, up to the black plate that the inducer motor is mounted on (from diagram looks like that plate is called the "front header box"?

Ok,remove the tube from the black plate and blow through that end.

Once you think you have the drain clean,power the furnace back up and see what happens. Does the motor seem to be running really slow? Can you hear the water slushing?

Did that, wasn't clogged. Also blew through small gray hose that goes from gas regulator, up to pressure switch. It made a clicking noise up at the pressure switch when I blew into the bottom of it by the gas regulator.

How would u like me to fire? Should I have gas ignitor to on, fan on, power on, and then turn thermostat on to see if it lights (normal startup) and does the front panel have to be on to have it work?

Gas valve on,fan switch auto and blower door must be on.

You can leave the top door off,just to see if it's going to light. Do you hear water slushing in the inducer?

No water. But when I remove small grey tube from gas regulator, plug with my finger, the light turns solid red for about 6 seconds, then goes back to flashing twice.
Is there a way to tell if propane is getting to the furnace, its on at the pig, but...

Does the ignitor ever glow?

No glow

Ok,locate the pressure switch,do you see the rubber tube that is connected to the pressure switch?

2 actually. Small & grey. One in front of the other. One goes to inducer motor & the other splits and goes to the box where u can see the flame and the gas valve

OK,the tube that goes to the inducer motor hooks to the pressure switch on the other end.

Yes

Shut furnace off,remove tube from inducer only,power furnace and suck on the tube like a straw,you will hear a click keep sucking keeping a vacum on the tube until you see an ignitor glow.

Your furnace should have a plastic exaust pipe,does it vent through the roof or the side of the house?

Did that, it glowed, then when I stopped, it stopped glowing

Roof

Ok, two pipes?

Two pipes go up through roof

How cold is it outside?

19 degrees. And we just got DUMPED on with snow over the past 3 days

Most likely something is blocking the intake or exaust. It could be a chunk of ice or even a bird or wasp nest. When either pipe is restricted the pressure switch will not close.

K, check and make sure snow or ice is not covering the intake and exaust on the roof, I'm willing to bet you have a ball of ice over the intake.

You're a genius. Thank u so much! I will get someone up there tomorrow to try and clean out. Thank u again

No problem,let me know if that does it. Won't you need heat through the night?

Hopefully someone pays u for this! Happy Holidays!

Have a pellet stove that'll last me through the night. But there are NOOOO pellets in Michigan. Lack of sawdust or something.

You too! No pay, I do this for the fun of it. I'm a serviceman for a living.

Really? I'm not surprised. Outdoor woodstoves are really big here,driving the cost of wood really high.

Really appreciate it. You've helped me tremendously. I hope someone returns the favor to you someday!

Wood stove would have been nice. I live on a family owned 100 acre parcel of nothing but hardwoods! Trees, trees everywhere... but not a drop of sawdust. ;)

No problem at all! If you have any more problems someone on this forum is always happy to help.

Cut some trees down,then you'll have saw-dust... lol

Good night

You too! Good luck!

Check your draft hood, if you don't have one the wind will open your pressure switch, or your hood is pushed in blocking the gases from going out

THANK YOU!! This response reminded me about our intake outside on the side of the house... and the 4ft of snow that hasn't been shoveled on that side all winter! Problem solved!

Intertherm.. OH BOY lol.. yes they have a rep for that . Ive been a HVAC tech for 24 years they have a HIGH altitude pressure switch that works better ( not great . Ive found the best is to replace the pressure switch with a adjustable. You can set them to where they work perfectly every time ( Ive NEVER had to go back on one Ive used them on. Johnstone supply is where I get mine. They do cost around 35 dollars but well worth it on sib zero nights