Theoretical question..........

Roland_18

Let's say I have a simple NON-mod-con boiler with outdoor reset and I short the thermostat wires together to create a constant heat demand. Also, the warm weather shut down function is disabled. What should happen in this scenario considering an outdoor temperature of 90*F+??

Thanks, Roland.............

Steamhead

If the ODR is working

the boiler should not fire.

LarryC

Theoretical answer .....

It depends.







What does the thermostat wires control, the circulation system or the burner?



If it controls the circulation system, then the pump(s) or fan(s) will be running.



If it controls the burner, then the the burner should fire, until something shuts off the burner like a hight temperature safety switch, or aquastat high limit, or ODR controller.



How low does the ODR curve go?  Is there a minimum system temperature that the ODR will not go below? 



Just guesses from a non heating professional.

gennady

question

WWS controls boiler pump and system pump, if P/S piping is utilized. or or just system pump if boiler bypass is used,and boiler ,if boiler is used only for heating purposes. Outdoor reset controls diverter valve in non mod boilers. so if WWS is not used, then boiler will stay 180F, pump will pump water trough the heating system, and diverter valve will keep temperature of this water at temperature corresponding outdoor reset curve settings.