Posted on

How to Replace Your Watkins No-Fault Heater (10 Easy Steps)

Blog Featured Images 90-

In this post, we will give you a step-by-step guide for replacing your spa’s Watkins No-Fault Heater. Just follow these steps and your spa will be up and running in no time!

how to replace your Watkins No-Fault Heater

It’s a beautiful, brisk, spring morning. The birds fill the air with music; glorious sunbeams stream through the tree-tops like glowing waterfalls. What a perfect morning to sit and wake up slowly in a warm soothing spa. I happily walk over to my spa, filled with anticipation… I remove the cover only to find an ice cold, lifeless, pool of dissatisfaction! Nooooooooo… Alas, I am doomed. (I know it’s a little dramatic, but you get the point.)

Table of Contents


Risk Of Electrical Shock – Always verify that all power is turned off to the subpanel that powers your spa.

Tools Needed-

  • Hose Clamp Pliers ( or Wine Corks!)
  • Needle Nose Pliers
  • Phillips Screw Driver
  • Flat Head Screw Driver

Step 1

Power down your spa by unplugging it from the outlet (120V Spas), or turning off at the main sub-panel breakers (220V Spas).

Step 2

Remove the front panel of the spa to gain access to the equipment compartment.

Step 3

Open the Control Box in the equipment compartment and locate all of the cables that lead to the heater. Be sure to make a note of where all of the heater cables are plugged in on the circuit boards. Disconnect all of the cables (from the circuit boards) that lead to the heater.
NOTE: Do not unscrew the sensors from the heater at this point; just unplug them from the control box.

Step 4

Locate the copper bonding wire and disconnect it from the heater. Leave the other end connected to the control box.

Step 5

With the heater cables and bonding wire disconnected, pinch and slide the 3/4″ tube spring clamps back from the inlet and outlet ports of the heater. Do the same for the 1/4″ tube spring clamp located on the backside of the heater.

Step 6

Use a heat gun or blow dryer to heat up the 3/4″ tubing attached to the heater inlet/outlet. This makes the tubing much easier to remove.

Step 7

Remove the 3/4″ tubing from the heater inlet/outlet.
Quickly remove and plug the 3/4″ tubing, one tube at a time.
Use hose clamps to stop the water flow to the heater.
The faster you do this step, the less water you will lose.
PRO TIP: You can use wine corks to plug the 3/4″ tubes!

Step 8

Remove the 1/4″ bleedline tube from the backside of the heater.

Step 9

Unscrew the heater from the equipment compartment floor and remove the heater from the spa.

Step 10

Carefully unscrew the thermistors (sensors- products #79005, #79006, or #78969 and #78970 if your spa thermistors plug into the outside of the contolbox) from the heater and remove the o-rings. Always replace the thermistors when replacing the heater.

To install the new Watkins No-Fault Heater, simply reverse steps 1-10!

  • Install the thermistors into the heater
  • Screw the heater to the floor of the equipment compartment
  • Attach all of the plumbing
  • Slide the spring clamps into position
  • Plug all of the cables coming from the heater into their proper places in the control box, and reinstall the copper bonding wire.
  • Screw the lid back on the control box and secure the front panel (door) back into place.
  • Restore power to your spa and enjoy!

Backyard Plus is Here For You.

Questions regarding your spaContact us! We are the top Hotspring spa parts retailer on the web. We offer:

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!