Aqua-Hot 400 Series Service Manual page 19

Fluid-Level Sensor: Serial #: A400-130104 - Current
The fluid-level sensor monitors the level of antifreeze and
water heating solution within the Aqua-Hot's boiler tank to
ensure that an adequate volume exists.
Troubleshoot the fluid-level sensor if one of the following
condition has occurred:

The Propane-burner and/or electric heating element
fails to operate.

The Aqua-Hot fails to operate and the "Low Tank-Level
Cutoff" indicator light on the electronic controller is illu-
minated.
Troubleshooting:
Troubleshooting
1. Verify that the Aqua-Hot's boiler tank is full of the anti-
freeze and water heating solution.
2. Verify that the wire connector is securely plugged into
the fluid level sensor and secured within the boot termi-
nal.
3. Verify that the fluid level sensor wires are securely in-
stalled in the terminal strip on the wire harness, as well
as tightly fastened to the electronic controller (wires 15
and 16).
4. Verify the functionality of the fluid level sensor by com-
pleting the following:
 Install a jumper wire on the JP3 plug,, between
pins 15 and 16 (between "LLCO-1" and "LLCO-0"
on the electronic controller in order to bypass the
fluid level sensor.
 If the "Low Tank-Level Cutoff" indicator light on the
electronic controller extinguishes when the jumper
wire is installed, inspect the wire harness and the
inline AMP circuit for damaged or severed wires. If
no wires are found to be damaged or severed, fol-
low the instructions to replaced the AMP circuit.
 If, however, the "Low Tank-Level Cutoff" indicator
light continues to illuminate once the jumper wire
is installed, follow the instructions to replace the
electronic controller.
Replacement Procedure:
Failure to disconnect all power supplies and/or to allow the
heater to cool before servicing could cause serious damage
or personal injury.
Replacing the inline AMP circuit:
1. Remove the AMP circuit from the main harness by dis-
connecting the quick connect terminals from wires 15
and 16.
2. Remove the boot terminal from the fluid level sensor.
3. Using a 3/8 hex socket, remove the nut holding the
ring terminal to the ground stud. The stud is located
adjacent to the fluid level sensor.
4. Take the ring terminal of the new AMP circuit and place
it on the ground stud. Torque the nut to 20 in/lbs.
5. Place the boot terminal from the AMP circuit and place
it on the fluid level sensor.
6. Take wires 15 and 16 from the harness and connect
them to the AMP circuit. The orange wires connect to-
gether and the black wires connect together.
Figure 10
ELX-800-005: Switch, Fluid Level Conductive
ELX-AMP-005: Circuit, AMP
© Aqua-Hot® AHE-400-P01 Service Manual Rev.B June 2014
Section #: Title
Aqua-Hot Components
AMP circuit boot terminal
p.
19