Buck Booster- Combustion Blower Fan - Aqua-Hot 400 Series Service Manual

Buck Boost Converter - Combustion Blower Fan
Function:
The purpose of the Buck Boost Converter is to maintain a pre-
set output voltage,
NOTE: There are two Buck Boost Converters. One is for the
Combustion Blower Fan, and the other one is for the Hot Sur-
face Igniter.
Replacement Indicator:
Replace the Buck Boost Converter if it fails to
operate properly or is damaged.
Troubleshooting Procedure:
NOTE: The interlock switch will prevent the Propane-Burner
from operating without the access cover intact; therefore,
the switch will need to be manually pressed during this trou-
bleshooting procedure.
1. Turn the Propane-Burner Switch to the ON position, on the
Interior Switch Panel.
2. Verify the following:
A. The control Thermostat is calling for heat.
B. The interlock switch is not tripped.
C. The float switch is not tripped.
D. There is 12 VDC going to the Propane-Burner
Controller.
E. The Left High Limit Thermostat (Wires 32 & 35) is not
tripped.
F. 10 Amp blower fan fuse is not blown.
3. Verify that the Propane-Burner Controller is sending power
to the Buck Boost Converter at the BLO pin, on the control-
ler.
A. If the propane burner controller is not sending a power
signal to the buck boost converter, replace the pro-
pane burner controller.
4. Verify that the Propane Burner Controller is sending a
ground signal to the buck boost converter at the GND pin,
on the Controller
A. If the propane burner controller is not sending a
ground signal to the buck boost converter, replace the
propane burner controller.
5. If the propane Burner Controller is sending power and
ground to the buck boost converter, verify that the buck
boost converter is receiving the power and ground signals.
Through the individual wires. The power wire is #92, the
ground wire is #95.
A. If an individual wire is not sending the proper
signal, replace that individual wire.
6. Verify that the buck boost converter is sending power and
ground to the combustion blower motor, wire #99 is the
power wire, and wire #98 is the ground. This voltage
should be approximate 12.5 VDC, when the supply voltage
is between 11 VDC - 15 VDC.
A. If the voltage going to the motor, from the buck
boost converter is not 12.5 VDC, when the supply voltage
is between 11 VDC - 15 VDC replace the buck boost con-
verter.
Figure 63
© Aqua-Hot® AHE-400-P01 Service Manual Rev.B June 2014
Section #: Title
Propane-Burner Components
Combustion Blower Fan
Buck Boost Converter
p.
67