Lochinvar HERALD HCB116CE, Installation Manual

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21.5.10 F
AN
S
PEED
L
IMITING FOR
I
NDIRECT
DHW T
ANK
This parameter determines the maximum fan speed (and therefore the maximum kW rate) to be used when heating
an indirect DHW tank. This setting may be used when the tank is unable to accept all of the kW available from the
boiler. This parameter may be adjusted by the installer by accessing the Fan Speed Limiting for Indirect DHW Tank
parameter. The default value is the maximum fan speed for that model.
21.5.11 DHW T
YPE
This parameter determines whether the boiler treats the indirect DHW tank as a separate load or as a zone on the
primary loop. When programmed as a separate load, the boiler will turn on the DHW pump and then turn off the
boiler pump when an indirect DHW demand begins. When programmed as a zone, the boiler will turn on the DHW
pump, leave the boiler pump on and change the system set point to the DHW boiler set point (DHW Boiler Set point
parameter).
This setting may be changed by the installer by accessing the DHW Type parameter. The choices are NORMAL and
ZONE. The default setting is NORMAL.
21.5.12 SH/DHW S
WITCHING
T
IME
When a boiler has a space heating demand and it receives a DHW demand, it will immediately switch to the DHW
demand and start a timer. Once the timer has expired, the boiler will switch back to the space heating demand and
start another timer. Once this other timer expires, it will switch back to the DHW demand. The installer can adjust
the length of time the boiler will service the space heating demand by accessing the SH/DHW Switching Time
parameter. The minimum setting is 0 minutes and the maximum setting is 55 minutes. The default time is 30
minutes.
21.5.13 DHW/SH S
WITCHING TIME
When a boiler has a DHW demand and it receives a space heating demand, the SMART SYSTEM control will start a
timer. Once the timer expires, it will stop the DHW demand and service the space heating demand. The installer can
adjust the length of time the boiler will service the DHW demand by accessing the DHW/SW Switching Time
parameter. The minimum setting is 0 minutes and the maximum setting is 55 minutes. The default setting is 30
minutes.
21.5.14 DHW F
ORCES
S
YS
P
UMP
When the indirect DHW tank is connected as a zone on the primary loop, the DHW Forces Sys Pump parameter tells
the system pump if it must run when there is a DHW demand. To have the system pump constantly running during a
DHW demand, set the DHW Forces Sys Pump parameter to YES (the parameter DHW Blocks Sys Pump must be set
to NO). If this parameter and the DHW Blocks Sys Pump parameter are both set to NO, the system pump operation
will be based strictly on the System Pump Type parameter setting. The default setting of this parameter is YES.
21.5.15 DHW B
LOCKS
S
YS
P
UMP
When the indirect DHW tank is connected as a zone on the primary loop, the DHW Blocks Sys Pump parameter tells
the system pump if it is allowed to run during a DHW demand. To force the system pump to turn off during a DHW
demand, set the DHW Blocks Sys Pump parameter to YES. The default setting is NO.