How to Retrofit a 1989-1996 Hot Spring Spa with the IQ 2020 Eagle Control System

Welcome to Backyardplus! I this post, we show you how to retrofit your 89-96 Hot Spring spa with the 76836 Eagle box, 77433 Control panel and the 6kW double barrel heater. Before we get started, let’s go over the tools and parts you will need.

Tools you will need:

• Phillips head screwdriver
• Small flat head screwdriver
• Heat gun
• Wire strippers
• Vice Grips
• Needle nose Vice Grips
• Crimping tool
• Pliers
• Duct tape
• Dow Silicone
• Christys Red Hot PVC Glue
• Jigsaw
• Drill
• Flat file
• Dremel tool with plastic cutting wheel
• Compound miter saw

Parts you will need:

• 76836 Eagle Control Box
• 77873 Control Box lid
• 36018 Mounting Bracket
• 77433 Control Panel
• 74930 LED Light
• 76227-AM 6kW/1.5kW Heater
• 79005 High Limit Thermistor
• 79006 Temperature Control Thermistor
• 70315 ¾” Vinyl Tubing x 2
• 70318 ¼” Vinyl Tubing
• 300055 ¾” Spring Clamp x 8
• 31134 ¼” Spring Clamp x 3
• 31417 ¾” Barbed Adapter x 4
• 30643 ¾” 90 Degree Elbow
• 30656 45 Degree Elbow
• 70382 ¼” Barbed Coupling
• Ring terminal
• Flag terminal x 6
• 73335 Flat Slat x 2
• Wood screws ½”  x 6

Step 1. Disconnect power from the spa.

Step 2. Drain the spa.

Step 3. Remove the circulation pump, heater and disconnect the bonding wires.

Step 4. Install the new heater and circ pump to get correct measurements.

Step 5. Remove the old circ pump inlet tubing. Glue the 45 degree elbow to the two barbed adapters.

Step 6. Measure and cut two pieces of ¾” tubing. Install it on the circ pump inlet along with the 45 degree elbow and spring clamps.

Step 7. Measure and cut the ¼” heater drain tubing and connect it to the old tubing with the ¼” coupling and spring clamps. Connect it to the heater drain with a ¼” spring clamp.

Step 8. Measure and cut the heater outlet tubing and install it with the spring clamps.

Step 9. Connect the circ pump inlet tubing with the spring clamps.

Step 10. Glue the 90-degree elbow to the barbed adapters.

Step 11. Measure and cut a small piece of ¾” tubing. Install it on the circ pump outlet with a spring clamp.

Step 12. Install the 90-degree elbow with a spring clamp.

Step 13. Measure and cut a new piece of ¾” tubing. Install it on the 90-degree elbow and heater inlet with the spring clamps.

Step 14. Remove the sensors from the thermowell. 

Step 15. Loosen the screws and remove the control panel.

Step 16. Loosen the screws on the mounting plate and remove the control box. Disconnect the bonding wires and the magnetic door switch.

Step 17. Loosen the four screws and remove the mounting plate.

Step 18. Install the IQ2020 control box bracket with two screws.

Step 19. Install the LED light with the duct tape.

Step 20. Remove the lid and install the Eagle box on the mounting bracket.

Step 21. Connect the two 73335 tongue and groove slats together, cut them to the correct length and put a screw in each corner.

Step 22. Mark the hole to be cut for the control panel with a sharpie.

Step 23. Cut the hole with a Dremel tool or similar saw.

Step 24. Finish trimming the hole with a jigsaw and smooth the edges with a flat file.

Step 25. Place a ¼’ bead of silicone around the entire edge of the control panel, install it in the opening and plug it into the control head interface on the motherboard.

Step 26. Plug the temperature control thermistor (heater inlet) into the REG THERM port on the motherboard.

Step 27. Plug the high limit thermistor (heater outlet) into the LIMIT THERM port on the motherboard.

Step 28. Plug the pressure switch into the PRESS SW port on the motherboard.

Step 29. Plug the LED light into the light adapter and plug the adapter into ZONE 1 on the motherboard.

Step 30. Cut the old J&J plug off of the circulation pump cord and install flag terminals with your crimping tool.

Step 31. Using your Vice Grips, install the circ pump cord and strain relief clamp into the opening and connect the circ pump to the terminals on the motherboard. Connect the green wire to J45, black to J34, and white to J42.

Step 32. Using your Vice Grips, install the heater cord and strain relief clamp into the opening. Strip the wires and connect the heater to the terminals on the motherboard. Connect the white or black wire to H1, and the white or black wire to H2. Crimp a ring terminal to the green wire and secure it to the ground screw just below the terminal block.

Step 33. Cut the old J&J plug off of the jet pump cord and install flag terminals with your crimping tool.

Step 34. Using your Vice Grips, install the jet pump cord and strain relief clamp into the opening and connect the jet pump to the terminals on the motherboard. Connect the green wire to J29, white to J28, and black to J27.

Step 35. For 120 volt operation, install a power jumper between terminals 4 and 5, and another one between 6 and 7. Install a wire jumper between terminals 6 and 2. For 230 volt spas, no power jumpers are needed.

Step 36. Using your Vice Grips, install the power cord and strain relief clamp into the opening. Connect the green wire to the ground lug, white wire to terminal 7, and black wire to terminal 5.

If your spa is a 230-volt spa, connect the 30-amp wires to terminals 2 and 4. Connect the green wire to the ground lug. Connect the white neutral wire to terminal 7. Connect the 20-amp wires to terminals 5 and 6.

Step 37. Install the control box lid. Connect the bonding wires to the bonding terminal.

Good Job!

Watch the video here! “How to Retrofit a 1989-1996 Hot Spring Spa with the IQ 2020 Eagle Control System”

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