Welcome to Backyardplus! In this post, we are going to show you how to replace the temperature control thermistor or regulating thermistor in your Hot Spot and Solana spa. If the “Ready” icon is blinking on your control panel or, your control panel reads 50 degrees, it is an indication that the temperature control thermistor is not working. Before we get started, let’s go over the tools you will need.
Table of Contents
Tools you will need:
- Phillips head screwdriver
- Silicone grease
Step 1. Disconnect power from the spa.
Step 2. Drain the spa to the just below the temperature control thermistor wall fitting in the filter compartment.
Step 3. Remove the Equipment door and the control box lid.
Step 4. Unplug the temp control thermistor from the J7 Regulating Thermistor port on the motherboard.
Step 5. Remove the insulating foam (if there is any) from the thermistor and unthread the nut from the wall fitting.
Step 6. Remove the nut, O-ring, and insulating foam from the old thermistor and install them on the new thermistor.
Step 7. Cover the O-ring with silicone grease and install it inside the nut.
Step 8. Thread the new temp control thermistor onto the wall fitting and tighten it with your hand.
Step 9. Cover the thermistor with the insulating foam.
Step 10. Plug the new temperature control thermistor into the J7 Regulating Thermistor port on the motherboard.
Good job!
Watch the video here!
Questions about your spa? Contact us! We are the top Hotspring spa parts retailer on the web.
Call us at (805)541-9000
Text us to receive technical support
In addition to “How to Replace a Regulating Thermistor in a Hot Spot and Solana Spa,” we offer:
- Our Parts Finder which allows you to find exact-match replacements for your hot tub
- Free technical support that will allow you to maintain and repair your own spa accordingly
- Information regarding your products and their usage through our blog posts.
- Tutorials and assistance through our videos
- Follow us on our Facebook page
Our goal here at Backyard Plus is to help save you money by avoiding costly service calls for repairs that you can easily do yourself!