Heating a Hot Tub Off Grid

Hot Tub in our courtyard

It seems like a lot of people believe that you can’t have a hot tub and be off grid. Well, I thought the same thing. I went through all the possibilities. I thought of wood, I thought of propane, I thought of electric but none off these seemed like a solution. I really like the idea of woodfired because I have a lot of wood available, the only problem is it is messy and it takes a long time to get it started heating. Besides it had to be something that my wife liked and she did not like that. The next option seemed to be propane. Most of the propane options have a hot element sitting in the water with you which is not appealing to me or my wife. The final option seemed to be electric and that was not appealing because it would draw way too much power. I finally settled on a one 110 volt Hot Tub thing, well, we’ll figure it out from there.

Sure enough, after installation, the 110 Volt heater would heat it up at about 1 degree per hour. It was mighty slow. At this rate it would take all day to it it up just 8 degrees. I wanted some way to assist the electric to make it heat faster but was reluctant to cut into the plumbing on the unit. During he building process I had a Camplux propane, point of use water heater that was made to take showers while you’re camping out. That makes it very portable. All it needs is a pressurized water source and a tank of propane. The tank of propane was easy enough because I had plenty of cylinders for a barbecue grill. The water source was a little more difficult. I had to take water from the hot tub, run it through the propane heater and back into the hot tub. At first I tried 12 volt DC pumps but none of them I tried lasted very long. I thought of a bilge pump for a boat would work well but the ones I tried just didn’twork out. What did workout was a 110 volt submergible pump that I connected to the heater with vinyl tubing. Since I didn’t want the water pump running all day I only put it down when I need to heat up the hot tub.

Submergible Pump
Camplux water heater
Water Heater in use

Now when we want to use the hot tub I’ll go out about 30 minutes ahead and put the submergible pump inside the hot tub, turn on the propane and plug it up. The water temperature will increase about 5 degrees in 30 minutes. This may sound like an unorthodox way to heat the water but it was the only way that I could figure that worked for us. It was especially important to me because the hot tub was one of the prerequisites that my wife had for going off grid.

I hope this helps some of you who want to have a hot tub ven though you’re off grid.

Below is a link to the Camplux on demand hot water heater