David,
It will get very warm in the aqua hot compartment. The unit will heat to 180 degrees or so and how much heat depletes from the compartment will be a function of outside air temp, air movement, and vent area. The vent area is small, and it sounds like air movement and outside temp are not helping much.
A good indicator of this systems proper operation is the expansion tank. If you are not above the high mark and the burner has shut off then that would indicate that the fluid is at a proper temperature. You could check the load panel for AC amps and see if the electric element is turning off properly. Lastly, I own an inexpensive IR gun ($50)
and I can point it at the metal pipe just under the radiator cap and read the temps. That would provide real data and 165 to 180 degrees would be normal for that location.
Obviously if one of the heating systems is not shutting down or if the expansion tank is beyond its high mark then have the system checked out. If not, turn it back on and get hold of an IR gun and take some readings to calm your nerves. Hope this helps.
Regards Ed
