1.43 Water Thermistor (TH-1) Replacement

Power Down The Plunge

• Pause the chiller by pressing the pause button on the UI
  • ⚠️ Powering down the Plunge while it's in a cooling cycle can damage the chiller.
• Press the test button on the GFCI outlet to power down the Plunge.
• Unplug the GFCI outlet from the outlet.

🚨Close Auto-Doser Ball Valves🚨

• Close the two auto-doser ball valves (perpendicular to the piping).
• Important note: Not closing the ball valves will cause the auto-doser probe to dry out and need a recalibration.

Drain The Plunge

• Remove the right ventilation screen. Opposite of the filter housing.
• Locate the main drain manifold at the bottom and remove the cap from the spigot.
• Attach a garden hose or inline pump to the spigot
• Turn the valve on the spigot and the water should flow out
• Turn the valve to close the spigot and install the cap back on.

Remove Chiller Vents and Thumb Nuts

• Remove both chiller vent panels.
• Unscrew all 5 thumb nuts:
  • 3 from the left chiller vent
  • 2 from the right chiller vent
• Note: Bottom-right nut may be an 8mm hex nut—use socket if necessary.

Remove Rear Cover

• Slowly pull and wiggle the rear cover out through the vent openings.

Remove E-Box Cover

• Use a 2.5mm hex screwdriver to remove the 4 screws securing the e-box cover.

Unplug & Remove Water Thermistor (TH-1) From E-Box

• Locate the water thermistor (TH-1) plug inside the electrical box using the PCB Board diagram
• Using a flathead screw driver, press the tab down and pull the plastic connector the unplug the water thermistor (TH-1).
  • ⚠️Do not pull by the wire. ⚠️ 
• Remove the water thermistor (TH-1) wire from the E-box by feeding it through the hole in the back. 
  • ⚠️Do not pull by the wire. Puss the plastic connector ⚠️

Cut Zip Ties Securing Flow Meter Wire

• Cut the zip ties securing the water thermistor (TH-1) wire to the chiller. 

Remove The Water Thermistor (TH-1)

• Disconnect the water thermistor (TH-1) manifold from the water filter housing
  • ⚠️ If a hand tool must be used to loosen it must be pliers with soft tips. Non soft tip tools will damage the union. ⚠️
• Remove the water thermistor (TH-1) by unscrewing with pliers.

Install The Water Thermistor (TH-1)

• Screw in the water thermistor (TH-1) water thermistor (TH-1) by unscrewing by hand. Then use pliers to ensure it is secure and water tight.
• Connect the water thermistor (TH-1) manifold to the water filter housing.
  • ⚠️ Hand tighten only. Do not use tools to tighten unions. ⚠️

Plug Water Thermistor (TH-1) Into E-Box

• Gently feed the water thermistor (TH-1) wire into the E-box from the hole in the back
• Locate the water thermistor (TH-1) plug inside the electrical box using the PCB Board diagram
• Plug water thermistor (TH-1) into appropriate port.

🚨 Plugging water thermistor into the wrong port will result in the Plunge not functioning properly. 🚨

Secure Flow Meter Cord Using Zip Ties

• Secure the water thermistor (TH-1) wire to the other cords along the top of the fan. 

Test for Leaks & OR Error Code

• Fill the Plunge up with water so the water line is 6" below the edge of the tub.
• 🚨 Open the auto-doser ball valves🚨
  • ⚠️ If chiller is turned on while auto-doser ball valves are closed it can damage the chiller.⚠️
• Plug in the Plunge and press the “Reset” button on the GFCI plug to power it on.
• Set temperature to 50 degrees so pump powers to 100%.
• Allow the Plunge to run and observe the chiller plumbing union connections.
• Carefully inspect all union fittings for any signs of leaking while the system is running.
• If a leak is found, pause the system and recheck that the union is properly seated and hand-tightened.
• Confirm no "OR" error code on UI

Power Down The Plunge

• Pause the chiller by pressing the pause button on the UI
  • ⚠️ Powering down the Plunge while it's in a cooling cycle can damage the chiller.
• Press the test button on the GFCI outlet to power down the Plunge.
• Unplug the GFCI outlet from the outlet.

Prepare for Rear Cover Installation

• Reattach e-box cover (4 screws).

• Secure chiller to frame using the 4 base nuts.

• Pre-install the upper thumb nut (near filter housing) loosely—this area is tight with cover on.

Install Rear Cover

• Carefully slide rear cover over chiller.

• Ensure power cord is routed through the correct side.

• Reinstall all 5 thumb nuts to secure rear panel.

• Attach the left and right chiller vents.