Arrived quickly. Glad I happen to have the correct PC board, no advanced warning for that.

Ordered hot button for a tankless water heater. When part arrived it was incomplete. Called and spoke to customer service after a few days, the part arrives in the wrong color. It was in brass when I originally ordered it in chrome, incompetent. Will never do business with this company again.

I installed the Hot Button controller kit on a 240A unit with a p23 version main circuit board. In the end it works, but there are some limitations on how I wanted to use it. My intent was to limit the circulations to decrease natural gas cost. With the idea that I would kick off a recirculation when needed. However, I wanted to continue to run the weekly circulation schedule over a more targeted time frame. However, once you install the hot button controller kit, it disables the weekly schedule. There is also limited and conflicting information on dip switch settings. I have a dedicated return line, and what I ended up with is all dips on the 10 dip block of the front control turned off. Then dips 1&2 on the 4 dip blue block of the main board tired on. Then all dips on the 6 dip black block of the main controller board off. So the hot button kit does work, I just didn’t work as I would have preferred.

So to get around it, I installed a Shelly1 Gen4 device to be a dry contact controller that could also run limited schedules. It’s a Matter over WiFi device that integrates into Apple HomeKit. That way you can simply say Siri turn on Hot-Water. For scheduling you add the schedule in Shelly and press the button automatically for auto scheduling. That works better than you might think in that with the Hot button kit thermostat attached to the hot water return line, if the temp is still past 100 degrees, the button push is simply ignored.