Coolant Temperature Sensor (ETS)
Introduction:
The ETS module precisely measures the temperature of the coolant inside of the Aqua-Hot boiler tank. This allows for very granular control of the unit to deliver precise heating and hot water as needed.
The ETS module went live on the Aqua-Hot 450-DE5 series. Older units utilized the control thermostat.
The ETS module should be diagnosed if the Reporter is displaying an incorrect temperature when accompanied by issues such as lack of interior heat or hot water.
Troubleshooting Procedure:
- 1. Locate the thermostat within the Aqua-Hot and its associated wires.
2. Verify that these wires are not corroded, cut, or otherwise damaged.
3. Check the J8-6 and J8-3 pins on the Reporter to check for cut, corroded, or otherwise damaged wiring.
4. Using a meat thermometer, measure the temperature of the tank face of the Aqua-Hot.
5. Record this temperature on a notepad.
6. Locate the Reporter, and access the home page.
7. Find the element entitled “COOLANT TEMP”.
8. If the temperature displayed is not approximately the same as the temperature recorded earlier, the ETS module will need to be replaced.
Replacement Procedure:
- Clamp shut the zone hoses to prevent the zone from draining.
- Open the unit drain valve located on the bottom left of the heater, and allow approximately 2 gallons to drain from the unit.
- Disconnect the wires of the existing ETS module.
- Using a 10mm socket deep-well socket, remove the defunct ETS module and discard it.
- Place the new ETS module onto the tank face, and finger tighten it.
- Using a 10mm deep-well socket, tighten the ETS module until it is snug. DO NOT OVER-TIGHTEN THE ETS MODULE
- Reconnect the wires of the ETS module.
- Test the Aqua-Hot for normal operation.
p. 16
Aqua-Hot® 450D Service Manual REV 231114
Documents / Resources
 |
Aqua-Hot 450-DE5 Coolant Temperature Sensor Module [pdf] Owner's Manual 450-DE5, 450-DE5 Coolant Temperature Sensor Module, Coolant Temperature Sensor Module, Temperature Sensor Module, Sensor Module |