I'm probably the only one ever to do this.
A week or so ago I had Fred come out to do some "stuff" and that including servicing the Aqua Hot as it was beginning to smoke a bit. All went well but he noted that my coolant level in the expansion tank was near the bottom and that I should check it more thoroughly. So today I figure was a good day to tinker and the first thing was to put some coolant in the tank...up to ~1/2. Than fired her up so I could get it hot, run the heaters and look for leaks.
SHOULD HAVE READ THE BLOODY MANUAL.
Before the unit reached full operating temp, the coolant was ready to overflow the expansion tank. Thinking back it was only about 50F when Fred did the service and 11 gallons of coolant has a LOT of expansion as it heats. Now I get to drain some out.
Manual specifically states: Check coolant when HOT.
Dick with egg on face.
