Troubleshoot: Hot Tub or Swim Spa Not Heating

A common issue with hot tubs is that the heat pump or circulation pump may stop working. This can be daunting for first time purchasers of hot tubs. If your spa seems to be working properly but your hot tub water is cold, this guide will walk you through a few simple steps to try before contacting your friendly neighbourhood hot tub technician.

Step 1:

Is the hot tub in Economy Mode? Economy modes often allow the temperature to drop around 10-11 degrees from the set temperature before the heater kicks in. Sometimes it can be easy to accidentally put the hot tub into economy mode with a sequence of button presses, or with kids playing around with the topside control.

To navigate to the economy mode setting on a Self-Cleaning Hot Tub: Settings > Water Care > Find Water Care Profile > Press Pencil Icon on Righthand Side. At the top of the page you'll see two tabs, Filtration and Economy. Choose the Economy Tab and from here you can set up economy mode timings by adding an Economy Cycle. The Self-Cleaning Economy Mode is off if the Standard Mode is green checked on (see image below).

Example of Hydropool Self-Cleaning Control Showing the Economy Water Care Settings

To navigate to the economy mode setting on a Serenity Hot Tub: Press and hold the light button 5 secs until clock hours flash on display > tap button until you see "EP" > Use Arrow Keys to Navigate to 0 (mode disabled) or 1 (mode enabled) > Press Light Button to move to "ES" for Economy Start Time > Use Arrow Keys to Choose the Start Time > > Press Light Button to move to "ED" for Economy Duration > Use Arrow Keys to Choose the Length of Mode > Tap Light Button until You Return to Main Screen. You will know the program is on if the display toggles between time, temp, and ECO.


Step 2:

Can you see water flowing as normal, or is the water still? 

Make sure there are no Error codes displayed on your hot tub's topside control. Codes read as: FLO, FL2, HL, and DRY. These error codes will suspend your hot tubs normal working actions, no pumps, circulation, or heating. See our guide to learn what these codes mean, and how to troubleshoot them. 

We want you to be able to swiftly solve any problem you can to get you back to relaxation, see our guide on how to solve Flow Errors for more solutions. 

If your hot tub isn't heating but you have no error code proceed to the next step. 


Step 3:

Check your breaker settings. Following your spa model manual, you should be able to find out what your spas RCD Amperage settings are. Please follow your manuals guidance or consult your spa dealership prior to changing any electrical settings for your hot tub.

If your spa amperage setting is not correct it may be switching the heater off while running the pumps, to avoid drawing too much power and tripping your RCD. For example, a 32amp tub (as described in the spa manual) may be set to 16amps, only allowing limited functions of the pumps and heater at any one time. Don't change any setting unless advised, you can do serious damage by running your hot tub at the wrong amperage. You don't want to knock out your neighbourhood grid!

If you’ve considered all of the above and are still having issues, call your dealership or hot tub technician (That might be us!). They may be able to suggest further steps for you brand or hot tub, or recommend a call out.


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