I'll try to remember to take one when I get home. The small water heater
I got at Home Depot. THe first one was 1.5 gallons, but it didn't get
drained completely one fall and split during the winter. Couldn't find
the same one, so got the 2 gallon one. Don't remember the manufacturer.
The circulator is a standard home heating system circulator designed for
zone heating.

Ben wrote:
How about a picture of your setup and maybe the manufacturer of that
2 gallon water heater?