Hi there, I just bought a house that has an Apollo Hydroheat system. The unit is about 10 years old. Any time we use hot water, there is a very loud "water hammer" sound in the pipes, specifically, right near the water heater itself. I tried to drain the system of any calcium buildup, but when I tried to drain it, I was only to get about a gallon of water out of it. I was told that I need to get an expansion tank to stop the noise. Does anyone think and expansion tank will help? Or is the water heater getting to old and need to be replaced? Any help would be great.
