Hamilton Engineering EVO Plus Series - To Turn off Gas to the Appliance; Pump & Wiring Control

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PART 7. SERVICING
Code Cause Recommended Action
P05 Water ow too low through appliance Check for partially closed valves, pump impeller fouling etc.
P06 Water ow blocked during a burn cycle (proof of ow) Check for partially closed valves, pump impeller fouling etc.
W04 Minimum water pressure Water pressure too low (within 10% of minimum pressure required), conrm cause and correct.
TABLE 73 BCB HARD LOCKOUT HLO CODES (continued)
NOTE: In many cases, a “hard lockout” will indicate that there is something wrong with the appliance, that should be
serviced or repaired.
EXAMPLE:
If there is a loss of flow due to an air bubble passing through the appliance (sensed via the water pressure transducers),
the appliance will shut down and display a temporary fault of P04 or P05 A, B, or C. When flow resumes and a waiting
time has elapsed, the control board will perform a pre-start diagnostic and then resume a burn cycle.
E. TO TURN OFF GAS TO THE APPLIANCE
1. Set the thermostat to lowest setting.
2. Turn o power switch on front of unit.
3. Turn o all electric power to the appliance if service is to be performed.
4. Turn gas shuto valve clockwise to “o.” Handle will be horizontal. Do not force.
F. PUMP & WIRING CONTROL
The EVO control board has an on-board relay for controlling the circulating pump. On a call for heat, the pump will
start, allowing the water flow proving circuit to be made and the pre-start diagnostic to continue. After the call for
heat has been satisfied, the pump will continue to run for the factory programmed period of time (1 minute) and then
shut o. For water heating applications an external temperature sensor must be mounted in the water storage tank.
For heating applications, the call for heat must come from an external source (room thermostat etc.).
G. TO TURN OFF GAS TO THE APPLIANCE
1. Set the thermostat to lowest setting.
2. Turn o power switch on front of unit.
3. Turn o all electric power to the appliance if service is to be performed.
4. Turn gas shuto valve clockwise to “o.” Handle will be horizontal. Do not force.