Delta-T Hardwired AC Differential Temperature ControllerWrite a review

I replaced a 25 year old controller for my solar hot water heater here in Florida. Direct replacement and worked with out any changes to the system other than replacing the electric valve. I hope it will last another 25 years.
I did add a light to show when ever its on which is nice to know when it is working even on a cloudy day. I also added a heater strip to prevent freeze up which has burst tubes twice even with 2 thermal drain valves.

My 25 year old, handwired controller stopped working, and it wasn
t the solenoid this time. I researched the internet for a replacement and found the Delta-T, from The Alternate Energy Store, with the best price. The instructions, and installation, were straightforward. It
s been working as promised for 2 months. I wish I could have paid less for it, but isn
t that always the case?

I wish I did not buy this unit. A $5. Timer to the circulator pump is all you need. On cloudy days, a common light sencer that turns on the power when the sun hits it activates the circulator pump. If your water temp get over 190 Degree
s, temp sensor clamped to the hot output of the tank will break the circuit to the circulator. This sensor is $15 and is the size of a large watch battery with 2 electrical spades connections on it. This way of doing it stops the circulator pump running unnecessarily.

I will say, going solar hot water is awesome. I never run out of hot water and it saves me over 75% on my hot water fuel bill. Plus I have 18 feet of base board in the basement plumbed to the return feed to the roof panels. That free heat eliminated the musty smell in the basement.

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