Weil-McLain WM97+100 Manual page 84

WM97+ Series 2
DHW SETTINGS menus
TEMPERATURES (DHW)
— The WM97+ control gives priority
DHW priority
to DHW operation. During DHW call for heat, the
space heating zone ouputs (Zone 2 and Zone 3) are
disabled. This continues until the DHW call ends
or the DHW MAX ON TIME has elapsed.
BOILER SUPPLY
1. The WM97+ control will regulate boiler firing to provide
outlet water at this temperature.
2. For most DHW applications, set this to 190°F. A lower supply
temperature can be used, but will reduce the indirect water
heater heating capacity.
BOILER ON DIFF
1. The temperature must drop this many degrees below target
temperature for the boiler to come on.
BOILER OFF DIFF
1. While the boiler is firing, as the temperature increases above
the target temperature, the boiler firing rate is reduced.
2. At this many degrees above the target temperature, the control
will temporarily turn off burner. The burner will be restarted
when temperature drops below TARGET TEMPERATURE
minus BOILER ON DIFF.
Figure 94 DHW SETTINGS menus (see Figure 87, page 77 for access information)
Menu/Item Units
DHW: Selection
Boiler Supply °F
Boiler Circulator Spd Selection
Modulate On Diff °F
Modulate Off Diff °F
Max On Time minutes
Prepump Time: ### seconds
SEC
Postpump Time: ### seconds
SEC
Maximum Rate
WM97+70 RPM
WM97+110HW RPM
*
WM97+110EBM RPM
WM97+155 RPM
Minimum Rate
WM97+70 RPM
WM97+110HW RPM
*
WM97+110EBM RPM
WM97+155 RPM
– 84 –
-
GAS FIRED WATER BOILER
(continued)
Low High
Default
Value Value
Off On Off
60 190 190
Off High Off
2 10 5
2 10 5
off 240 30
0 240 20
off 240 30
1100 4300 4150
1400 5650 5450
1900 7850 7550
1300 5500 5300
1100 4300 1100
1400 5650 1400
1900 7850 1900
1300 5500 1300
— Boiler Manual
Aqua Logic (CWH) Installations — See Aqua Logic manual
for control settings information.
TIMES (DHW TIMES)
MAX ON TIME
1. This is the longest time the boiler will continue in DHW
mode before switching to space heating (if there is a space
heating call).
Setting MAX ON TIME to off will cause the control
to never switch to space heating while DHW call for
heat is present. This could present a freeze hazard
for some installations if the DHW aquastat were to
remain closed indefinitely.
PRE PUMP TIME
1. The boiler circulator (if enabled) and DHW circulator will
start this amount of time before the burner is started.
POST PUMP TIME
1. The boiler circulator (if enabled) and DHW circulator will
continue this amount of time after the burner is shut down
when the call for heat is satisfied.
MIN RATE / MAX RATE
1. Use to set minimum and maximum boiler inputs by setting
minimum and maximum blower RPM.
Comment
This setting must be ON to operate in DHW mode.
Boiler enters manual reset lockout at 200°F.
Select speed or select OFF to deactivate boiler during
space heating call.
Boiler turns on if temperature drops below target minus
differential on.
Boiler shuts down if modulates past target plus differential
off.
Longest time boiler will satisfy this system before switching
to DHW.
Additional time to run circulators longer than standard 10
second time.
Circulator run time after call for heat ends.
Boiler Model and altitude specific
(derated automatically if HIGH ALTITUDE is selected in
control setup).
NOTE: Adjusting boiler firing rate will affect AFUE rating.
See Notice on page 79
*
Boiler Model and altitude specific
(derated automatically if HIGH ALTITUDE is selected in
control setup).
NOTE: Adjusting boiler firing rate will affect AFUE rating.
See Notice on page 79
*
Part number 550-142-204/0117