Have a tech call them from on site and trouble shoot the unit.
Rinnai propane heater error code 11.
Verify the proper flame rod wire is plugged into the proper flame rod.
Some units have multiple flame rods.
Perhaps because your ignition system is not working well.
What does that mean.
No flame in the combustion chamber gas installation with the gas regulator.
11 is no ignition and 12 is flame failure.
This includes the following.
Rinnai error code 11 is an indication that there is no ignition in or no gas supply to your hot water system.
You can try the following to fix the problem.
Check your hot water system for any visible damage or loose parts locate your gas supply and ensure it is turned on.
Rinnai tech support is excellent.
2 days ago started to get code 11 flashing and furnace stopped working.
Which means the unit had enough flow through it to call the unit on it just failed to light or maintain ignition.
Code suggested prob with ignition.
Technician service comp.
I dont think it s a flow issue.
Verify the flame rod is tight in its mounting bracket.
I have a rinnai hydronic furnace and tankless water heater 2 br home.
A quick check to verify correct wiring is to look at the stamped letter on the bracket at flame rod sample a y indicates yellow r red and b blue.
A loose flame rod is called a floating flame rod and will result in code 11 s or 12 s.