IBC SL 20-160 G3 Installation And Operating Instructions Manual page 88

As referenced on page 2-7 of this manual, the following message is relevant to users in the USA:
This Boiler is equipped with a feature that saves energy by reducing the boiler water
temperature as the heating load decreases. This feature is equipped with an override
which is provided primarily to permit the use of an external energy management system
that serves the same function. THIS OVERRIDE MUST NOT BE USED UNLESS AT
LEAST ONE OF THE FOLLOWING CONDITIONS IS TRUE:
• An external energy management system is installed that reduces the boiler
water temperature as the heating load decreases.
• This boiler is not used for any space heating.
• This boiler is part of a modular or multiple boiler system having a total input
of
300,000 BTU/hr or greater.
• This boiler is equipped with a tankless coil (not applicable to IBC's SL boilers).
IMPORTANT
US installers should contact IBC for any further information required.