I had one similar to that on my hot tub in Md. It was basically just 50' of copper tube in an oil drum. When I was burning coal it worked pretty well but far from efficient.
I got the coal free tho so I didn't care. I rescued a coal truck driver on I-270 one night and he dumped a bit over a ton of hard coal in my back yard a few days later as a thanks.

I reconized that model. It's the Git er Dun 2000. Classy

Jethro appears to have his head on fire.

Alan.,

Maybe so but that fire look not much smoke at all probly useing LP Gaz with burner nozzle in the bottom and aim upward.

Merci, Marc

Is the pump GFCI protected? And is the heater connected to the grounding grid?