Furnace cycling but no hot air

[Dui]

I have one empty tank. Flipped the switch to full tank. Have green light and can run stove no problem, but when I turn furnace on it tries to fire and the indicator goes red...any idea what is the problem?

[woodtic]

First thought is a bad hose or regulator.

When you say "green light", do you actually mean green indicator? Does the indicator return to green after the furnace fails to light?

Could be a internal tank valve issue if the tank is very full. Or you may have triggered the tank valves internal safety (excessive flow) shut off. In this case, close the tank valve completely, then re-open very slowly.

[Dui]

Thx for the reply Woodtic. Yes I meant the green indicator. It stays green but when I go to start the furnace the blower kicks in but as soon as the igniter tries to fire the indicator goes red. I turn off the furnace via the thermostat and the indicator goes green. I confirmed I still have flow via the gas stove. Cold night last night 3deg C. The fireplace took the edge off but still cold..any other thoughts ? I'll try opening valve slowly this morning.

[woodtic]

Something is limiting the flow of propane from the tank. Tank valve, hose, or regulator. Right now I would try moving the tank to the other side of the trailer and try it from there. That could narrow down the cause of the problem. Also double check that the regulator is switched to draw from the full tank. What side of the trailer was the tank installed on?

[woodtic]

The tank valve is actually quite more complex than you may think. There is a shut off valve, a check valve, a vent valve, a pressure relief device, an overfill shut off and, an excessive flow shut off, all packaged into one unit.

I have one tank valve that has a occasional problem with the check valve portion. The hose connection depresses (opens) it. On mine, sometimes the hose will not force it to open. When it sticks, I was told to bounce the tank on the ground a couple times, and then try it again.

Since you are getting some flow I doubt that is your problem but, bouncing the tank on the ground may help if something else is sticking in the tank valve assembly.

[Dui]

The tank was on the passenger side (door side). I moved the tank to the opposite door side and it now works. I believe the regulator, red one 20psi on the door side, is the issue as it appears to restrict flow when the furnace draw is high. Anyone experience this issue?

[woodtic]

Could also be the hose's internal check valve sticking. I would remove the hose and test it first.

Could also be that there was some moisture in the line and the hose valve froze up. Hose valve failures are quite common.

[Irlpguy]

Had the same problem with my 3402RL this winter and it was not the small red regulator. The hose that runs from the metal crossover pipe to the regulator had a bad valve and once replaced the problem was solved. The hose valves are a safety feature but are very subject to problems. I had a propane shop make me up a hose without the valve and that will never be a problem for me again.

I would suspect the hose is the problem, not either regulator.