LP system basics
The regulator drops tank pressure down to what the appliances use. If every LP appliance is weak, start at the tank and regulator.
The short version
- One appliance bad: look at that appliance. All of them bad: tank, valve, regulator or the safety valve tripped.
- Light a stove burner. Strong blue flame means gas is getting into the coach.
- Opening the tank valve too fast can trip the excess-flow valve. Close it, wait, open it slowly.
- Check pressure with a manometer, not by eye.
- Smell gas: shut the tank off and find the leak with leak solution, never a flame.
On the job
- Open cylinder valves slowly. A fast open trips the excess-flow check and you get a trickle.
- Light a stove burner first. Blue with sharp cones is good supply. Yellow or lazy on every burner is pressure.
- Manometer on the stove manifold or an appliance test port: 11 in WC with one burner lit, still above 10.5 with the furnace and water heater running.
- Lock-up: burners off, cylinder on. Pressure should rise to 11 and hold, not creep past about 14 in WC.
Numbers
- Appliance pressure: ~11" water column
- Acceptable range: ~10–13" WC
- Operating pressure: 11 in WC (10.5 to 11.5)
- Lock-up: holds steady, not creeping past about 14 in WC
- 1 psi: 27.7 in WC
- Regulator life: replace at about 10 years
Shop tip
Weak yellow flame on every burner after a tank swap? Close the valve and open it slowly to reset the excess-flow.
Try it on a service call
Put the lesson to work on a hands-on troubleshooting case.
Keep going on furnaces
Learn it
Prove it
- Furnace blows cold
- Furnace sparks but never lights
- Furnace keeps shutting off, fan keeps blowing
- Thermostat clicks, furnace does nothing
- Comeback: furnace quits again