Propane pressure issue. Help

[Cory Lee]

I’ve got a 120 gallon propane tank. It’s 80% full. The service tech showed 13” on his pressure gauge with nothing running & 12” with tankless & range running.

My tankless water heater codes out when I open a second faucet or turn the range on.

If I have the range running and turn the hot water on, the flame nearly goes out on the range for about 5 seconds the goes back to normal.

When the water heater codes out I have to turn all the hot water off to get it to reset. It’s a Rinnai 75ip. It’s giving me code 12 “no flame”.

Plumber says it’s gas regulator. Gas guy says it’s the water heater. Any help??

 

[Cory Lee]

Also, I’ve lived here 2 years and never an issue until 3 weeks ago.

The main pipe is 1 1/4” schedule 40 pipe with 3/4” pipe to the appliances. Water heater is at 40’ from tank. Range at 60’.

 

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[Reach4]

I don't think it is the regulator. I don't think it is the WH other than the WH represents a load.

It sounds as if there is a limited path between the regulator and the tee between the WH and range. How long is that path, and what size pipe is it? Search the pipe path where accessible for kinks and crushes.

How about giving the WH its own regulator close to the WH? Then high pressure runs to that regulator.

I am not a plumber or gas guy.

 

[Cory Lee]

It was the regulator at the tank. Thanks.

 

[hj]

You have to test the pressure AT the heater to see if there is adequate gas. There could be some obstruction reducing the operating pressure at the heater.