Originally Posted by DUTCH in Atlanta
Not so easy. On the Coachmen Galleria the Truma Combi (furnace and hot water heater combined)
is used. It is inside the coach. His water tank is outside and under the coach. He wants to protect it from freezing. 103F and/or 93F have no use for that purpose.
I would probably simply insert a tee fitting in the line between the tank and the pump, as near as possible to the tank. Then just epoxy the aquarium sensor into the third branch of the tee so that it is immersed in the water coming from the tank. The temperature in the pipe is more relevant than that of the tank anyway, since the pipes will freeze long before the tank.