The Pirelli is not in the best of shape so I will start with the sides because I have daylight through both seals where they fail to have contact. Not good in mosquito season.
I sent Bryan a copy of the burn figures and was surprised by a very thoughtful email from Don which is below. Quite helpful and its apparent that the heater is not putting out the temps he is use to seeing. I will check with suburban
"Stephen,
I am not totally familiar with the system Bryan installed, but I did install a similar system in an Alaskan which I used and which is now in Iceland working well and once I got the boiler/hotwater heater set to full max temperature output it worked well even at -40º camping in Montana. My system had a finned copper tube heat exchanger going around the perimeter of the bottom half at its top edge. This might be something you could accommodate into your current system. I also had an expansion tube at the high end of the system which was a “T” off of the main delivery line. This system does take space and require good air circulation up over and out other finned element.
Your low limit setting for the exiting water should be about 150º, the high limit setting should be about 190º, so it would appear your water temperature settings are too low.
The second thing I would suggest is to set the Alaskan on 3” of solid urethane foam board with a foil surface side facing up. This should trap most of the heat and reflect it up.
I had a very low amp draw circulating pump, I believe it was a March pump.
Don"