We have a gas pool heater that is less than 2 years old. We started having trouble with it knocking. 1000 dollars later it is working. The first issue that was identified was that the plumbing was wrong. The water was going in the heater at the out port and out of the heater from the in port. The pool installer came and fixed this issue. The heater continued to knock. So then the bypass spring was replaced as well as the thermostat. Still knocking. Last they ordered a kit to clean everything and replace some of the rings, etc.. The heater repair man cleaned out lots of scale. Now my heater works!
Why would I have so much scale in less than 2 years (we use the pool year-round)? Could it be the plumbing reversed? Could it be that I have hard water? What can I do to prevent this from happening again?
Thanks for your help!