I'm going to continue on this thread even though this is a bit of a tangent.
I have the Espar M2-B4L and live at 7200ft. I've had my heater installed for several months now but never ran it for more than 10 minutes or so just testing it and it always runs fine. Recently, it got cold out and I decided to run it to keep warm while working on the van. After running fine for about 25 minutes, the heater shuts down with these error codes:
P000129 (Flame cutout within the control range 75% – 100% )
P000342 (Invalid configuration, Check ADR coding).
This is repeatable and consistent, every time I try.
I found an Espar document called "Repair Instructions" and for the P000129 error it says to do a fuel quantity test to see how much fuel is being provided in 60 seconds. The document has a chart with min/max values. I ordered a graduated cylinder to perform this test. However, the document does not have any remediation steps should the quantity be too high or low. Anyway, once the cylinder shows up, I'll do this test.
Since it seems I may have a fuel problem, I inspected the fuel lines while the heater is running. I noticed there are air bubbles in the fuel line after the fuel metering pump but none before it. I found some references online that refer to tiny bubbles in the fuel line after the pump to be normal. I disconnected the fuel line on both ends of the pump and they look good. I trimmed some of the slack out of the line and reconnected with no change in behavior.
Here are a couple videos of the fuel line in action, unfortunately the video compression makes it a little tough to see:
Also in the "Repair Instructions" document, I see this reference: "– For precise fuel measurement, at least 11 / 22 volt or maximum 13 / 26 volt should be applied to the control box during the measurement."
My electrical system is based on a lithium battery and the voltage generally sits between 13.5 and 14.1. Espar support has previously requested that I change my system from lithium to lead-acid for the heater when debugging another issue but I couldn't pin them down as to why this would be necessary. I don't have a 12v 20A power supply to test with, but I'm thinking a regulator stabilizer like the MaxxAir fans require might be useful if the heater is also sensitive to the higher voltage.
Unfortunately, I don't know if I am experiencing 1 or more than 1 problem right now.
I'd appreciate any input.