Bradford-White Corp BWCH Manual De Usuario

Page 39

delay setting of 5 minutes. See 

Section 6.4.6

 for more 

information. 

 In modes other than mode 6, the pump will 

run continuously if the “HtD” and “ComD” terminals 

are jumpered and not connected to a zone valve or 

pump end switch, or other “contact closure” device 

to indicate when the heat demand in the system is 

satisfied. The pump will never run, and the boiler will 

never fire, if the jumper is removed and the terminals 

left empty.

OUTDOOR RESET (modes 4 and 5): Outdoor 

reset adjusts the target temperature based on the 

outdoor air temperature and reset ratio. The reset ratio 

is determined from the Boiler Start, Boiler Design, 

Outdoor Start and Outdoor Design settings.

HEAT DEMAND – For heat demand to exist, 

there must be continuity between the Com D (common 

demand) and Ht D (heat demand) terminals. The 
Copper Brute II ships with a jumper between these 

terminals. 

The control also evaluates the sensor(s) installed 

in the system. If the control is not in warm weather 

shutdown (WWSD), and the sensor(s) are below the 

target temperature, the “Dem” segment is turned on in 

the display. The control energizes the pump (on pump 

mounted boilers) and energizes both “PMP” terminals. 
The pump symbol appears in the display (see 

Figures 

25 and 26).

 The control then operates the stages to 

maintain the setpoint temperature.

Boil Start

 (Boiler Start): The BOIL START 

temperature is the theoretical boiler supply 
temperature that the heating system requires when the 

outdoor air temperature equals the OUTDR START 

temperature setting. 

For domestic 

hot water systems up to 175°F / 79°C, use mode 3 as 

described below. 

Step 1: Install the additional sensor into the 

storage tank, wiring it to “SC2” and “SUPS” terminals 

on the field wiring panel (

Figure 23

).

Press the three programming buttons 

to enter 

ADJUST mode (

Figure 25

). Press ITEM to 

select the programming item, and the arrow keys to 

adjust the setting. TARGET TANK is desired tank 

temperature. Recommended settings with a desired 

tank temperature of 125°F:

MODE 

3 

BOIL TARGET 

140°F 

TARGET TANK 

125°F 

DIFF TANK 

2°F 

BOIL MASS 

1 

DIFF 

2°F 

DLY 

5:00 

F° 

F° 

See 

Section 6.4.11 Limit Controls.

 

Set both high limits 25°F / 14°C higher than BOIL 

TARGET to allow for temperature rise across heat 

exchanger. Manual high limits on water heaters have 

a maximum 200°F / 93°C setting. (If water must be 

at 175°F / 79°C or higher with a volume water heater 

model, use mode 1. For volume water applications 

exceeding 200°F / 93°C, contact the factory.)

 For faster staging, increase BOIL 

TARGET setting. Larger DIFF TANK and DIFF 
settings will slow response to demand, but may save 

energy. 

If unit short cycles, enter Advanced 

Programming mode (

Section 6.4

) and increase 

BOILER MAX setting to the BOIL TARGET setting 

or higher. Set BOILER MIN to 120°F / 49°C, and 

STGMODE to PID. See 

Section 6.4.12

 Advanced 

 to enter Advanced Programming 

mode, or contact the factory for assistance.