7-day programmable night setback for space heating. Setpoint minus 0-90deg range.

7-day programmable night setback for DHW. Setpoint minus 0-90deg range.

Boost feature (up to setpoint +25deg) for higher firing rate under pre-determined conditions.

With that in mind, I could leave my t-stats at a constant temp 24/7, then program the boiler's control a few deg setback at night for sleeping comfort, program in the night setback stop time and let the boiler do the math to keep us warm.

Can someone explain the role of the "included Grundfos UPS15-58F boiler circulating pump" vs. the also required"system circulator pump"?

Thanks.....