We bought this for our pool, at first we thought we got a dud!! Read the instructions! The heater won_ actually kick in if the flow of water is too fast! You need to have a slower flow then you will hear the heater kick in. Once we figured that out it was nothing but smooth sailing! We put a valve to slow the water at the exit of the heater.
Still haven_ used the product due to needing a electrician to put power cable which you have to buy separate and also hose fittings along with a extra hose, so it is quite costly
Our spa quit working and we discovered it was the heater. We found this heater and it was exactly what we needed. It was easy to install and works perfectly going on 6 months now and we have had no issues. Excellent product.
I have been using the Pool heater for about a week and it is working great. We have a stand up Pool and we live in Vancouver, Canada and the water is perfect to be in the Pool all day. You have to get a professional electrician to do the connection and that_ it. 5 stars because the product it_ very good and good customer service. Thank you so much for such a great buying experience.
We bought this heater for our aboveground pool, so we could swim all winter (in California) We had to have it wired, as it states, and have 220 current installed, and now it's working great! The pool is warm, and we are very happy with this heater
Valerie 
