Hi all, back to Apollo troubleshooting? I have an Apollo Hydroheat system, Model L 55H 1GC. The hot water line that comes from the furnace (with temp gauge) to the water heater starts to vibrate and squeal after about an hour of turning the furnace on. I originally thought it started at a certain air temp. but during this cold snap the vibration and gurgling comes on a lot quicker, about 20-30 minutes after startup... Is this a pump issue? Doesn't sound like bearing noise, hard to describe. Hard water is an issue from my well, any guesses?
