Burnham CHG225 - Manual (Page 47)

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3) Two basic types of errors codes are shown on the display:
• Soft Lockout Codes – When a soft lockout occurs, the boiler will shut down and the display will alternate
between the number “9” and the letter “b” followed by a two digit service code. A list of these
codes, and their meanings, is shown in Table 13.3. The boiler will automatically restart once the condition that
caused the lockout is corrected.
• Hard Lockout Codes – When a hard lockout occurs, the boiler will shut down and the display will
flash the letter “E” followed by a two digit service code. A list of these codes, and their meanings, is
shown in Table 13.4. Once the condition that caused the lockout is corrected, the boiler will need to be
manually reset using the RESET button on the display.
4) If an outdoor sensor is installed, the boiler will automatically adjust the heating zone set point temperature
based on the outdoor reset curve in Figure 11.4. The maximum set point is defined by parameter 4 (factory set
to 180°F) when the outdoor temperature is 0°F or below. The minimum set point temperature shown is 100°F
when the outdoor temperature is 60°F or above. As the outdoor temperature falls the supply water target
temperature increases. For example, if the outdoor air temperature is 30°F, the set point temperature for the
supply water is 140°F.
5) An indirect water heater thermostat can be connected between terminals 7 and 8 on the terminal strip. When
this thermostat closes, the central heating circulator will be turned off and the DHW circulator will be turned
on.
6) An external limit control can be installed between terminals 3 and 4 on the terminal strip. Be sure to remove
the jumper between terminals 3 and 4 when adding an external limit control to the system. If the external limit
opens, the boiler will shut down and error code “b 26” will be displayed. If the limit installed is a manual
reset type, it will need to be reset before the boiler will operate.
Table 11.3: Boiler Status Codes
First Digit Boiler Status
0 Burner off - No call for heat or DHW
1 Pre-purge or post-purge
2 Ignition
3 Burner responding to call for heat
4 Burner responding to call for DHW
5 Checking air pressure switch
6 Burner off - Set point temperature has been reached
7 Call for heat ended. 10s heating post pump period
8 Call for DHW ended. 10s DHW post pump period
9 and b
Flashing
Burner off - on soft lockout. See Troubleshooting
Section to determine meaning of error code.
A Boiler responding to call from heating zone
H Burner on - Held in high fire
L Burner on - Held in low fire