Lochinvar 400 - Manual (Page 66)

Installation & Operation Manual
66
OPERATION DISPLAY
8. If the space heating call for heat is active, and the tank thermostat
or sensor starts a DHW call for heat, the boiler will switch to the
DHW mode. If programmed for normal DHW operation (not as a
zone), the DHW pump will turn on first, then the boiler pump will
turn off 2 seconds later.
This will divert the boiler’s outlet water from the heating system
and send it to the tank coil instead.
The control will then modulate to maintain the outlet temperature
to the DHW boiler set point.
9. If the boiler is not part of a Cascade, and both the space heating
and DHW calls for heat remain active long enough, the boiler will
switch back and forth between the two heating modes until one of
them is satisfied.
10. Once both calls for heat are satisfied, the control will turn off the
burner. The blower will continue to run during a 10 second
postpurge.
11. Any pumps that are running will continue to run for their
respective pump delay times before turning off, unless
programmed to remain on continuously.
A 60 second anti-cycle period will start, which will delay any new
call for heat until it times out.
12. In Standby, ready to start a new cycle.
Sequence of operation
(continued)
11
Operating information