8
Minimum Target
(Available when Startup Control Mode = Outdoor Reset)
Options:
From 70
º
F/21
ºC
to 180
º
F/77
ºC
Default: 70
º
F/27
ºC
SET
SET
SET
SET
SET
SET
/Set Point/<Out. Reset>/Min. Tgt
Min Target:
120 F
• The Minimum Target Temperature must be set to the boiler manufacturer’s specification. The HWE-SS will calculate the Target
based on the Outdoor temperature (OD), the Reset Ratio, and the Offset value. The HWE-SS will control the boiler to hold either
the calculated temperature or the Minimum Target Temperature whichever is higher.
• The Minimum Target Temperature must be at least 20°F lower than the Maximum Temperature (See next setting).
Maximum Target
(Available when Startup Control Mode = Outdoor Reset)
Options:
From 90
º
F/38
ºC
to 240
º
F/116
ºC
Default: 240
º
F/116
ºC
SET
SET
SET
SET
SET
SET
/Set Point/<Out. Reset>/Max. Tgt
Max Target:
200 F
• This is the highest temperature heating water the HWE-SS will circulate through the heating system. It
must be at least 20°F higher
than the Minimum Temperature.
• When using a radiation system, it should be set according to the tubing or floor manufacturer’s specification.
Differential
Options:
From 1
º
F/1
ºC
to 20
º
F/11
ºC
Default: 5
º
F/3
ºC
SET
SET
SET
SET
SET
SET
/Settings>/Diff.
Differential:
5 F
• The Differential controls boiler cycling. When there is a call for heat, the boiler will be activated until the Calculated temperature is
reached. The boiler will then turn off and stay off until the system water temperature falls to the Set Point less the Differential.
• A smaller Differential setting will normally result in tighter control of the set point but will tend to increase the frequency of boiler
cycling. Larger Differential values will reduce boiler short cycling, but the system will be allowed to vary further from the target
value.
Run-On
Options:
From 0 min to 60 min
Default: 2 min
SET
SET
SET
SET
SET
SET
/Settings>/Run On
• The SYS relay will energize whenever the Outdoor temperature is below the Outdoor Cutoff.
When the Outdoor temperature increases 2°F above the Outdoor Cutoff and after the boiler relay
has de-energized, the SYS relay will stay on for a period set by the System Run-On. This allows
the Pump to dissipate the residual heat within the boilers back into the system.
• A common use for the System Run-On is to provide extra time for the for the Pump to help transfer
the heat from the boilers to the heating system.
Pump Run-On:
2m
• The System Run-On time should be set based on the size and type of the boilers and pumps. In general, a boiler with large water
content and high horsepower will need a longer System Run-On than a boiler with the same horsepower and less water content.
(Refer to boiler manufacturer recommendation).
• When DHW Priority is active while the TSTAT is open or the outdoor temperature is above the Outdoor Cutoff, a DHW call will
energize only the DHW relay. When the DHW call expires, the DHW will run for the Run-On period then de-energize.
Domestic Hot Water (DHW) Priority
Options:
NO and From 1 min to 120 min
Default: NO
SET
SET
SET
SET
SET
SET
/Settings>/DHW Prior.
DHW Priority:
60m
• If the DHW Priority value was set to other than NO, it will provide the user with an adjustable DHW priority timer. That is, when
a DHW call starts, by closing/shorting the
T3±
terminals, the system relay will de-energize for the period set by the DHW Priority.
However, the DHW relay will remain energized for as long as the DHW call is active. The System relay will resume its operation
when the DHW timer expires or if the DHW call ends. This will take place whenever the outdoor temperature is below Outdoor
Cutoff and the TSTAT terminals are closed/shorted.
• If NO was selected as the option for the DHW Priority, a DHW call will energize both relays, System and DHW even when TSTAT
is de-activated.
Setback
Options:
From 0
º
F/0
ºC
to 80
º
F/44
ºC
Default: 11
º
F/6
ºC
SET
SET
SET
SET
SET
SET
/Settings>/Setback.
• The Setback feature can be used to provide the HWE-SS with a lower temperature Set Point when
less load is required.
• The lower Set Point will appear on the main display indicating
SBC TGT=
.
Setback:
20 F
SYSTEM=
68 F
SBC TGT=
140 F
