Electric Tankless Water Heater Installation for a New ADU

Adding an ADU to your property is a big deal. Whether it's a guest house, a rental unit, or space for family - one of the first things you have to figure out is hot water. Running a new line off your main tank isn't always practical, and cramming a bulky traditional water heater into a small space defeats the purpose of keeping things efficient.

That's exactly the situation we were working with here. The solution was a Rheem Performance electric tankless water heater mounted directly on the exterior wall of the ADU. No tank, no wasted square footage inside the unit. Just a compact, wall-mounted system that heats water on demand - only when you actually need it.

One thing we always include on tankless installs is a scale filter, and you can see the ScaleRX inline filter we added to this setup. Hard water is rough on tankless heaters. The heating elements take a beating over time, and scale buildup is one of the fastest ways to shorten the lifespan of the unit. Adding a filter upfront protects the investment and keeps the system running the way it should. We also insulated the copper supply lines and plumbed in proper shutoff valves so the system is easy to service down the road.

ADU plumbing has to be done right from the start. There's not a lot of room for shortcuts when you're building out a separate living space. Every connection, every valve, every fitting matters - both for code compliance and for the people who are going to be using the space every day.

If you're building out a guest house or adding an ADU to your property and need the plumbing sorted out, this is the kind of work we do.