Wireless Solar Water Heater Controller Ensures Hot Water Every Time


[Peter Sobey] had a solar hot water heater installed in his home, which worked great until he relocated his kitchen to a neighboring room. Now a good bit further from the tank, the hot water reaching his sink was tepid at best due to the increased distance and temperature limiting mixer valve in the new heater.

He installed a salvaged solar panel and water tank solely for use in his kitchen, but as the panel was located above the tank, he had to find a way to actively monitor and control the water temperature. His pump and valve system was originally driven with an off the shelf PICAXE-based controller, but he eventually got the urge to add a wireless display and control panel to the mix.

A pair of Arduino Nanos run the show now, one of which resides in the pump controller box, while the other is used in the temperature display box in his kitchen. He uses a set of Bluetooth modules to link the Arduinos together, relaying temperature data and allowing him to send the pump controller manual commands if needed.

He says the system works a treat, and he’s much happier with his homebrew controller than the one he used originally.

8 thoughts on “Wireless Solar Water Heater Controller Ensures Hot Water Every Time

  1. Wouldn’t it be easier to just run the water around the house at a higher pressure? and in a loop that keeps the water around the whole house at the same temp but wastes not but it only being a small amount flowing around.

    Then just put loads of insulation on that pipe and have next to no temperature loss.

    1. It is not feasible to hold hot water in an insulated pipe. Losses are related to volume and surface area so the best place to store the hot water is in a tank (spherical if possible!). Pipes have a large surface area to volume and no matter how well you insulate them lose heat very quickly. Plus, it was easier to put a system outside my kitchen than trying to put more pipes into an existing structure.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.