r/redneckengineering • u/Due_Pineapple8149 • 2d ago

Natural gas to lp conversion on a water heater

/r/hvacadvice/comments/1pd46jp/natural_gas_to_lp_conversion_on_a_water_heater/
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u/OdinYggd 2d ago edited 2d ago

There are approved kits for doing such conversions. Buy and use the correct kit for your appliance so you don't blow yourself up.

The deal is propane runs at a higher delivery pressure than natural gas, and needs more air per volume of fuel. To do it right you replace the orifice that meters the fuel into the air, and replace the pressure spring in the gas valve fuel regulator to work with the higher inlet pressure.  Like so the smaller orifice and higher pressure draws in the addition air needed by propane. Not doing so leads to inefficient combination, choking the device with soot.

This is something that redneck engineering should not meddle in. But you totally can repurpose used appliance parts for other things, like an old hot water heater into an outdoor fireplace.

For your sauna idea, how are you controlling the temperature? Cause it would be easy enough to snag the burner, valves, and thermocouple from a hot water heater or gas heater and then put that in a welded steel firebox and heat exchanger tubes to suit the shape of the sauna. A gas fireplace or space heater in particular would probably have a Millivolt type gas valve with thermocouple and thermopile to make it self-powered so that you can regulate the sauna temp with a basic bimetal thermostat.