Hello all. New pool owner this year (bought the house with the pool). Got it going and have been using the pool for a few months. This site is awesome! Anyway, today our Hayward nat gas pool heater began to make a knocking sound. It happened about 20 minutes after start up. After doing some research it seems that I may have a broken bypass valve, or calcium build up in the heat exchanger. Hopefully it is the valve since that fix seems much cheaper!
My question to you experts is this. I do not know what a normal condition for the heater is when I take the valve out and inspect, so what should I be looking for once I have the inlet/outlet pipes disconnected? Will I be able to visibly see a calcium issue if that is the case?
Any help here is appreciated!