Install Instructions

The control will continue to target the DHW setpoint
until the time limit is reached or the demand is
satisfied. Then, if there is still a CH demand, it will
shut down the DHW pump, start the CH pump and
target the required CH temperature.
If there is a central heating demand during a DHW
call, the boiler will continue targeting the DHW
setpoint with the DHW pump operating and the CH
pump idle until the time limit is reached.
For example, if the CH/DHW Switch Time is set for
30 minutes, and a CH demand is activated after 6
minutes of a DHW call the following will occur. The
boiler will continue to target the DHW setpoint and
the DHW pump will continue to run for the remaining
24 minutes. After which time, the control will shut
down the DHW pump, start the CH pump and target
the required CH temperature.
3. Store Warm Hold:
When using a DHW tank sensor, the P
UREFIRE
®
boiler
control can detect if the DHW heat demand is required
only to overcome standby heat loss in the tank and is
not a result of a hot water draw. In this instance, the
burner will fire at low power (1% on the display) and
continue until the tank setpoint is satisfied.
4. Heat Dump Function:
Brookhaven National Laboratories have performed
studies that show diverting excess boiler heat to the
DHW tank after a CH demand will greatly improve the
system efficiency of the boiler installation. The Heat
Dump Function is designed to take advantage of this.
Essentially the boiler will operate normally on a call
for heat. Once the call for heat ends, the pumps will
operate to dump heat to the indirect tank. Which
pumps operate depends on the pump mode and
DHW mode selected.
• Pump Mode 0 – DHW Mode 1 & 2
: The DHW
pump will operate to divert excess boiler heat to
the indirect tank. The CH pump shuts down until
this is accomplished.
• Pump Mode 1 – DHW Mode 1 & 2
: The General
pump will operate and the 3-way valve will direct
excess boiler heat to the indirect tank.
• Pump Mode 2 – DHW Mode 1 & 2
: The General
pump will operate with the DHW pump to direct
excess boiler heat to the DHW Tank. The CH
pump is deactivated.
The pumps/3-way valves operate to dump heat to the
DHW tank until the return temperature is less than the
installer selected “Min Diff” temperature or until the
“Max Time” limit is reached. This function can be
disabled by choosing “Off” on the menu under
“DHW Heat Dump.”
5. Maximum DHW Input Limit:
The P
UREFIRE
®
control allows the installer to limit the
maximum input of the boiler under a DHW load if
desired. This can be used when the boiler is sized
primarily for a CH load and is oversized for the DHW
load. This can be set between 50% and 100% and
the default is 100%.
6. DHW Response Time:
This feature allows the installer to adjust the response
time of the boiler. The “I” value is adjustable from 15
to 100 with 15 providing the fastest response. The
default value is 60. If the boiler achieves its setpoint
very quickly without modulating, increase the “I”
value to reduce the response time.
F. SERVICE NOTIFICATION
The PUREFIRE
®
boiler control allows the installer to enable
Service Notification through the installer menu. After
enabling this feature, the installer selects the number of
hours, the number of cycles, or the date when the
“SERVICE” text appears on the display screen. This will
prompt the user to call for service on the appliance.
The following chart shows the range and default values
for the Service Notification feature.
If desired, the installer can set a specific date for the
Service Notification.
To access the Notification menu operate the boiler under
System Test, enter the installer menu by holding down the
“Menu” and “Select” keys simultaneously for 10 seconds.
Then press the “
M” key until the “” indicates “Service
Notif.” Press the “Select” key to choose the menu.
The first option is to reset the Notification Timer /
Counter. Pressing the “Select” key will reset the timers
and counters and “Done” will be shown in place of
“Reset” on the lower right of the screen.
Pressing the “
M” key displays the “SERVICE Notification
on” screen. The default setting for “Notification on:” is
“Off” indicating that no notification will occur. The
installer can choose from the number of hours (HRS), the
number of cycles (CYCLES) or the Date at which the
“SERVICE” indication will appear on the display screen.
The menus that follow allow the installer to choose the
actual values for the Service Notification.
47
BOILER CONTROL: INTERNAL WIRING & OPERATION
Table 8.9: Service Notification Value Ranges
Notification
Min. Max. Default
On Off Off
Hours 0 8,000 4,000
Cycles 0 50,000 10,000