Onan 3600lp turns propane regulator to red

It is drawing faster than the cylinders can supply- it will actually draw from both cylinders if needed. Cold weather would make the problem worse.

If I understand you correctly, the l.p. regulator shows red flag empty
No control board fault is going to raise the red empty flag on the l.p. regulator,
That could only happen if l.p. flow was greater than the regulator can supply
You changed tanks and regulators
You have a physical/mechanical malfunction at the generator

MY THINKING is the vapor feed / regulation, at the Onan is too high it's basically flooding out, that's why it won't start, and why it is using such a high l.p. flow
Take it in to a shop, before something worse happens, like fire or explosion

Its been a while but I want to get back on this and see if anyone can help. I have the Onan service manual and have been going down through the trouble shooting procedures for error code 36 which is what I am getting. I have tried two different propane tanks, two different propane tank regulators. I have verified the generator electronic shut off valve is functioning, but I bypassed it anyway and plumbed directly in to the propane demand regulator. I have verified spark and put in a new spark plug just to rule that out. I constructed a small manometer and set up the test to verify the demand regulator is opening. I have done a compression check and am getting right at 90 lbs.

The generator will start and run on carb cleaner but will not start on its own. I am stumped now. As far as I can tell the 3600lp does not have a low oil pressure sensor that might be bad. I believe the only function of the circuit board prior to start is to open the electronic propane shut off valve, so I'm not sure it could be the board.

Looking for any ideas. I have the unit out of the 5th wheel now so I can take it in to a shop if I need to, but I would sure like to figure it out on my own.

Couple of questions:

Is this a liquid or vapor LP generator?

Never heard of a regulator with a light-- is this really the regulator or is this a propane detector?

Could the generator have it's own regulator that is acting up. The RV stove has it's own regulator to drop pressure below 11" wc.

I will start there tonight and get back. I blew through the vent tube and it seems clear but I think I will pull that out and just make sure it is not restricted.

riggsp wrote:
Sounds like the generator is pulling propane faster than the regulator or check valve in the tank will allow.

Soap Test all joints and connections - leak test.

Sounds like the generator is pulling propane faster than the regulator or check valve in the tank will allow.