ETS Module
ETS Module
©Aqua-Hot®
125-DN1 Service Manual
REV 220421
©Aqua-Hot®
125-DN1 Service Manual
REV 220421
p. 35
p. 34
ETS Module
Introduction:
The ETS (Engine Temperature Sensor) Module is a brass
thermistor that continually measures the temperature of the
fluid within the Aqua-Hot boiler tank. This module then relays
the information to the Aqua-Hot controller, thereby allowing the
controller to activate and deactivate the unit as heating and hot
water needs change.
Troubleshooting Procedure:
Troubleshooting the ETS module is a relatively straight
forward process. Follow the instructions below to diagnose
the ETS module. Troubleshoot the ETS module if the following
conditions have occurred:
• A lack of hot water.
• A lack of interior heat.
• The Aqua-Hot is not operating.
Verify the following before proceeding with the troubleshooting:
•
The overflow bottle is adequately filled.
• Ensure that DC electrical power is supplied to the Aqua-Hot.
• Ensure that AC electrical power is supplied to the Aqua-
Hot’s electric element.
• The high-limit thermostats are not tripped.
• All fuses are in working order.
If any of the above conditions are not
met, correct them before continuing with
troubleshooting. Results of the troubleshooting
procedure cannot be verified if the conditions
listed above are not fulfilled.
Using a meat thermometer,
measure the temperature
of the tank face. Record
this temperature on a piece
of paper.
Locate the Aqua-Hot LCD
screen. Navigate to the
DIAG page
Find INPUTS FROM AQUA-HOT,
and record the temperature
listed by TANK TEMPERATURE
(Figure 69). Record this
number on the sheet.
Are the recorded
temperatures
approximately the same?
Yes
This ETS
module is
functioning
as intended.
Disconnect the ETS
module from its leads on
the wire harness
Navigate back to the
INPUTS FROM AQUA-HOT
section of the LCD screen.
No
Yes
No
Does the Aqua-Hot display
any temperature?
Replace the
controller.
Replace the
ETS module
Figure 67
Figure 68
Figure 69
Replacement Procedure:
If the ETS Module has been diagnosed and a replacement
must be made, follow the instructions below.
1. Drain the unit by clamping the TO HEAT SOURCE hose
(Figure 70) located outside the Aqua-Hot, and removing it.
2.
Allow the fluid to drain into an external bucket or container
to be reused later. If necessary, activate the pump to aid in
draining the Aqua-Hot.
3. After approximately half a gallon has been drained from the
unit, clamp the hose to stop the flow of coolant.
4. Disconnect wires from the ETS Module.
5. Using a 14mm wrench or deep socket, remove the defunct
ETS module from the tank face and discard it.
6. Place the replacement ETS module in its position on the
tank face, and finger tighten it into place.
Figure 72
7. Using the 14mm wrench, tighten the module until it is snug
in place.
8. Reconnect the disconnected wires from the harness.
9. Reconnect the TO HEAT SOURCE hose to the Aqua-Hot and
remove the hose clamp.
10.
Pour the previously removed fluid back into the fluid
expansion bottle and allow it to fill the Aqua-Hot tank.
11. Once this has been completed, locate the Aqua-Hot LCD
screen, navigate to the test section, and run the fluid
circulation pump (and if applicable the boost pump) for at
least twenty minutes to purge the heating loop of air.
12.
Continually fill the fluid expansion bottle as the fluid level
drops.
13. Test the Aqua-Hot for normal operation.
Figure 70
Figure 71
ETS Module
Clamp across
this hose
Hose is highlighted in yellow
to properly show the process.
