Tankless Water Heater for Unlimited Hot Water

I honestly can't believe we went so long without this. Our camper came with the standard six gallon hot water tank with 120V AC or LP gas operation. Considering that modern "economical" shower heads of today's homes have limited the flow of water from 7 gallons per minute to around 2.5 in the past few decades, we aren't talking about very long usage here. I could typically last around 10 minutes in a shower, but my wife who likes a bit more heat than me was lucky to get 5 or 6, and that is with turning the flow off when she wasn't rinsing. On top of that, one of us (usually me) would have to wait at least half an hour for enough water to heat back up for a second usage. If we were on vacation with a couple of kids, the park shower houses would be the only option.

After a bit or research on tank expanders and the like, we decided to purchase a tankless water heater which could supply an endless stream of hot water. We went with this Girard model from PPL Motor Homes. I'm not going to try to explain how it works, but the temperature of the water is controlled by the flow. The unit kicks on when we open a hot water faucet and instantly heats the water based on how much water is flowing. We first open a faucet all the way, then slowly reduce the flow until the the water is at a desired temperature. It was a bit tricky to get used to at first, but after a bit of practice, this has been an invaluable addition to our home, and since the unit is only running when the water is flowing, it saves a lot of energy typically spent keeping a tank of water hot.

The original tank heater is hidden underneath the refrigerator and behind a lot of furnace pipes.

The tank wasn't the easiest thing to get out. Be sure to drain it from the outside and clean up afterwards. A lot of water will probably exit the lines as well.

The new heater uses the same water lines, although the bypass is not really necessary for weatherization. I did have to trim the PEX lines a bit for them to fit right. I really hate messing with those pipes.

Since I didn't buy a new door to cover the heater, I was able to salvage parts from the old one by breaking off whatever was necessary to mount the old door.

I did have to cut a hole in the original door for the exhaust to come out from the new heater. If I can find a small grill to cover this hole, I will add it later.

The outside panel has a lot of corrosion from the water weeping from pressure valve.

The new heater is not as big as the old one, so I had to add some new wood framing to secure it. The gas line also had to be straightened to go where it needed.

I put a strip of thick foam window insulation on either side of the heater to seal it to the frame. It is also screwed to the wood on all sides. A bit of spray foam further seals any cracks around the edges.

I also put a piece of mesh underneath the black trim to keep out any bugs that might want to make this a home. The bottom corner can be lifted up to get to the unit.

Finally, I wired the power switch to the original "Gas On" switch and used the original "Electric On" switch to select "Auto" or "Low" burner mode.