Lochinvar 402 - 2072 Plumbing Product User Manual


 
1 Service
10
Sequence of operation
Table 1A_(continued from previous page) Sequence of Operation - Space Heating and DHW
OPERATION DISPLAY
9. If the DHW thermostat remains on for more than 30 minutes,
and the space heating call for heat is also on, then the
control will turn on the boiler pump, turn off the DHW pump
after 2 seconds, and resume firing based on the space
heating setpoint. As long as both the space heating and
DHW calls for heat remain active, the control will switch
back and forth between the two modes until one of them is
satisfied.
HTR: RUN STG 12
OUT: 123.0F(129)
10. Once both calls for heat are satisfied, the control will turn
off the burners. The blower will remain on for the
30 second postpurge cycle. Any pumps that are running
will continue to run for their respective pump delay times,
then turn off.
HTR: POSTPURGE
OUT: 127.4F(129)
11. Boiler pump off, system pump continues its delay if
longer.
HTR: Standby
OUT: 124.7F(129)
12. System pump off.
HTR: Standby
OUT: 122.9F(129)
Copper-fin II/IIE Boiler and Water Heater Service Manual