First time poster here...We have a Water Furnace geothermal system that also is hooked up to our Marathon electric water heater. Cold water going into water heater has a "T" fitting that plumbs to the "in" port on the desuperheater. The "out" port plumbs into the bottom drain fitting of the water heater. Now for my question! We recently installed a solar array with a Tesla Powerwall battery. The Tesla App is awesome for monitoring usage. I can clearly see a spike every time the water heater kicks on. Now that we are getting into cooler weather overnite I can clearly see our water heater is kicking on MUCH LESS OFTEN which seems to correlate with the air conditioning not running at night now. This seems opposite of the way is should work. Is it possible for a desuperheater to malfunction? Hooked up backwards?? Side note - our geothermal is on a seperate electric meter that is not hooked up to the Tesla Powerwall, so the electric usage of the geothermal does not show on the Tesla App.

I think I may have solved the problem...we bought this house with the geo and WH already installed. There is no buffer tank. Seems that the lack of buffer tank is sucking heat out of the WH into the DSH. I bet it is really bad in the winter! Hopefully someone can confirm this. I'm looking into using existing electric WH as a buffer tank and going with a gas fired tankless after that.

Yes single tank set ups are not good.

Do you have room for 2 tanks? A heat pump hot water heater as your finish tank would be very efficient.

I get a lot of hot water from the DSH in winter with a 2 tank set up.

Chris

Many have found the DSH not really functional for the cost. and yes they can pull heat out of your water tank.

I had a climate master unit that the pump was froze up from new, it never worked and even after replacing the pump it wasn't worth the power usage.