Rinnai - Error Code 12 & Airflow Restrictor Cap

JLung

I've recently had a Rinnai 199iP indoor condensing how water heater. Supporting this installation I also had a 420# propane tank installed.

Problem - The Rinnai ignites and starts the burner kicks in, but then starts to "flutter" and ultimately kicks out an error 12, indicating it's not detecting a flame.

Obviously Solution - The unit isn't getting enough propane. The installer increased the line sizes, checked all the regulators, and I personally checked the pressure coming into the unit and get a solid 12.69 inches of water column, which in the required range of 10-14". The made quite a few changes, and while my propane stove works great, the Rinnai doesn't.

Called Rinnai Technical Support - After much discussion the tech support guy had us reach into the unit and block the fresh air intake that is inside that unit. And it instantly started working great. Solid flame, hot water, no error codes. We were told to order part # 108000106, which will partially obstruct airflow to the unit. Reason for the failure given was: "Your propane is contaminated and isn't requiring the rate of air being delivered to the unit to operate properly".

Why I'm asking for more information - I can't find anything on-line about this kind of failure. This unit is in my home in the basement and it doesn't feel right to me to restrict airflow in an imprecise way. Bad combustion usually = bad outcomes. Am I overreacting? Has anyone even heard of this issue?

Thanks in advance for any help / experience / input.

-Jeff

JLung

*bump* Has anyone seen / heard of anything like this before?