Is your Wave Spa controller showing an E5 error code (sometimes displayed as E05)? This guide explains what the code means and how to clear it at home.
What does the E5 error code mean?
The E5 error code is a temperature protection warning. The heater has detected that water isn't flowing through it properly, or that the temperature reading is outside its safe range, so it has stopped heating to protect itself.
In most cases, E5 is caused by something restricting water flow, and it can be cleared by following the steps below.
Common causes
Blocked or dirty filter: the most common cause. A clogged filter restricts water flow through the heater.
Low water level: if the water is below the minimum line, the heater can't draw enough water.
Bent or kinked pipes: a pipe or connector that isn't straight can restrict flow.
Limescale build-up: in hard water areas, scale can build up inside the heater.
Faulty temperature sensor: in rare cases, the sensor itself may be at fault.
How to clear the E5 error code
Please follow the steps below in order.
Step 1: Power off and let it cool
Turn the heater and filter off at the controller.
Unplug the spa from the mains.
Wait 15–20 minutes for the heater to cool down.
Step 2: Clean or replace the filter
Unscrew and remove the filter cartridge(s).
Rinse thoroughly under a hose or tap. If the filter is worn, torn or heavily discoloured, replace it.
Clean the hair guards and check the filter housing for debris.
Tip: to check whether the filter is the cause, leave the filter out, plug the spa back in and run Filter only (no heating) for a few minutes. If E5 doesn't appear, refit a clean or new filter.
Step 3: Check the water level
Make sure the water sits between the minimum and maximum lines on the liner. Top up if needed.
Step 4: Check the pipes and connectors
Check that the pipes and connectors between the heater and the spa are straight, not kinked, and hand-tight. Don't overtighten.
Step 5: Flush out limescale (hard water areas)
Turn the spa off at the mains and remove the filter.
Use a garden hose to run clean water through the inlet and outlet to loosen limescale or debris.
Use a net to remove any debris from the water.
Step 6: Reset and restart
Plug the spa back in.
Press the ON / RESET button on the RCD plug.
Turn the spa on and run the filter for a few minutes before turning the heater back on.
How to prevent the E5 error code
Clean your filters every 1–2 weeks and replace them regularly.
Check the water level before each use.
Keep pipes and connectors straight when setting up or moving your spa.
In hard water areas, flush the inlet and outlet regularly.
Still seeing the E5 code?
If the E5 code returns after all the steps above, there may be a fault with the temperature sensor or heater. Please use the chat widget at the bottom of the page and send us the following in one message so we can help quickly:
Proof of purchase or order reference number
A photo of the batch code on your spa (bottom-right of the warning/safety panel, e.g. "07 24")
A photo showing the entire spa
A photo of the controller displaying the E5 code
A photo of both filter areas
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