SaluSpa E03 Error: Water Too Cold? How to Clear It Safely

By Jake Weber · Published October 15, 2026

E03 means your SaluSpa’s pump thermometer is reading the water below 40°F (4°C), colder than the tub is designed to run. Bestway’s manuals say to unplug the pump and restart it only once the water reaches 43°F (6°C). The pump’s reading isn’t a measurement, so check with a separate thermometer: if it shows the water above 44.6°F (7°C) and E03 won’t clear, the manuals say the pump’s own thermometer is broken. That’s a Bestway support call. And don’t warm the pump with a hair dryer.

Which manuals this covers. I checked four Bestway owner’s manuals: AirJet Plus (2020, pump S100205: Vancouver, Milan), AirJet (2020, pump S100105: Miami, Bahamas, St. Moritz, Helsinki and others), Coleman 90363 (2017) and S400 (2023, pumps S400105/S400205). Same E03 rule in all four, different winter rules. Other pumps can differ, so your pump’s manual is the tiebreaker.

Safety note: check your pump against the 2024 recall. In September 2024 the U.S. Consumer Product Safety Commission announced a recall of about 866,000 Bestway AirJet and HydroJet spa pumps sold with SaluSpa, Coleman and Hydro-Force spas from May 2021 to May 2024, because they can overheat and catch fire (recall 24-359). Before troubleshooting anything below, read the model number on the label on the side or back of your pump. The recalled models are P05332, P05339, P05711, P05807, P07000, P07001, P05511, P07034 and P07572. If yours is one of them, stop using it and follow the CPSC recall notice or Bestway’s recall page for a free replacement or a refund. The SaluSpa pump recall guide walks through the label check and what to do next.

Before any step below:

• Unplug the pump before you touch it, its hoses or the filter. All four manuals: “You must ensure the pump is unplugged before beginning spa maintenance to avoid risk of injury or death” (AirJet Plus p. 19).
• Nothing electric within 5 feet of the tub, a DANGER rule in all four: no hair dryer, space heater or electric blanket.
• Don’t use the spa while E03 shows (Bestway’s online FAQ). Keep the cover on: “Water attracts children” (AirJet Plus p. 5).
• Never add water above 104°F (40°C). Measure it first.
• Test the GFCI plug when you plug back in. If the test fails, don’t use the pump.

What does E03 mean on a SaluSpa?

It’s a cold-water alarm, and all four manuals print the same E03 row. The pump’s thermometer reads the water below 40°F (4°C), for one of two reasons:

1. The water really is that cold. “The spa is not designed to operate with water temperatures lower than 40°F(4°C).”
2. The thermometer is wrong. “If the water temperature is higher than 44.6°F(7°C), the pump’s thermometer is broken.” That goes to Bestway support.

What differs is winter protection:

Bestway’s error-code blog calls 40°F “the lowest temperature at which the hot tub can run.” The blog doesn’t replace your manual’s exact numbers. Pages that call E03 a heater fault, a blockage or a reason to let the spa “cool down” don’t match these manuals.

Is the water really below 40°F?

Measure first, with a separate thermometer in the water, as Bestway’s FAQ says. The display isn’t exact: after at least a minute of filtering, the 2020 manuals still allow about 2°C, or 3.6°F, of difference from an external thermometer (they print “35.6°F”, a typo) (AirJet Plus p. 17). The Coleman manual asks for 5 minutes of filtering (p. 8; its p. 4 says one) and blames any gap on where the reading is taken.

• Below 40°F (4°C): the cold is real. Read on.
• 40 to 44.6°F (4 to 7°C): a gray zone the manuals don’t explain, and the display can be a few degrees off. Don’t call it broken: get the water to 43°F or a little above and retry.
• Above 44.6°F (7°C), and E03 is back after you unplug and plug in again: likely the thermometer. See below.

How do you restart a SaluSpa after E03?

All four manuals: “Unplug the pump and only re-start the pump when the water temperature reaches 43°F(6°C).” Bestway’s online FAQ says to wait for 10°C (50°F). I go by your pump’s manual and treat 50°F as the more cautious option, except in freezing weather (below).

Why 43, not 40? The manuals don’t say. Below 40°F is when the alarm shows; 43°F is when you may restart. Two different thresholds. Separately, the 2020 manuals’ winter setup page says fill water “must be above 42.8°F(6°C), otherwise when you begin to operate with the spa heater, the E03 alarm will appear” (AirJet Plus p. 11; AirJet p. 14). None of them explains the gap between 40, 42.8 and 43°F, and I won’t guess: use 43°F.

1. Confirm 43°F or more on your own thermometer.
2. Plug straight into a grounded outlet. Extension leads and multi-plug adaptors can overheat the plug (AirJet Plus p. 13).
3. Test the GFCI plug: plug in (red light), TEST (off), RESET (red: ready). “Do not use the pump if this test fails” (AirJet Plus p. 13; Coleman p. 6).
4. Heat on, cover on (AirJet Plus p. 17; Coleman p. 4).
5. Full tub with Freeze Shield? Then “do not switch off the spa heater if the temperature is lower than 42.8°F(6°C)” (AirJet Plus p. 17).
6. E03 back above 44.6°F? See the thermometer section below.

Expect a slow climb: even from 50°F, Bestway’s reference table lists 32 hours to reach 104°F, “purely for reference” (AirJet Plus p. 17). Details in how long a SaluSpa takes to heat up.

How do you get the water to 43°F without the heater?

The heater can’t help while E03 has you unplugged, and the manuals don’t give a method to warm the water. That’s a gap, not a ban on every method. These routes stay within their rules:

1. Mild weather. If it’s comfortably above 43°F day and night, with no frost forecast, unheated water warms with the air. Measure it and restart at 43°F. If frost is coming, go to route 4.
2. Filling or refilling anyway. Fill above 42.8°F (the 2020 manuals’ rule) and never above 104°F (40°C), the cap in all four manuals (AirJet Plus p. 5). Some owners use an indoor hot tap instead of a cold hose: fine if a thermometer reads 104°F or less first, since tap water can run hotter. No kettles, nothing boiling.
3. Bestway’s route. Its error-code blog (December 2023) says to unplug and disassemble the tub, then “Set it back up and run it again once temperatures are over 42ºF,” or to inflate it fully indoors and bring it back outside, “filling it with water over 42ºF.” That’s a full setup in the cold, so follow your manual’s cold-weather steps and its restart number (43°F), not the blog’s 42ºF. The 2020 manuals also “strongly recommend” not unfolding or inflating the spa below 59°F (15°C) (AirJet Plus p. 5, AirJet p. 4): wait for that, or inflate indoors. Model by model: how to set up an inflatable hot tub in winter.
4. Freezing, and you can’t raise the water. My rule: If it’s freezing and you can’t get the water to 43°F, don’t leave it full and unplugged — drain it. That’s my preventive call, not the manuals’ E03 procedure. E03 says unplug, yet the 2020 manuals want a full tub’s heater on below 42.8°F and, for a long absence with that risk, “strongly suggest disassembling the spa and storing it” (AirJet Plus pp. 5, 17); the Coleman manual says not to leave it out below 40°F (p. 3). Draining fits them all. With a recalled pump it’s the only route, since the CPSC says to stop using it (my call again). Steps: how to winterize and store it.

Can you use a hair dryer or a heater to clear E03?

No. Some quick answers online suggest warming the pump or its sensor with a hair dryer. The manuals’ DANGER rule forbids it: “Do not permit any electric appliance, such as a light, telephone, radio, or television, within 5 feet (1.5 m) of a spa” (AirJet Plus p. 4; AirJet p. 3; Coleman p. 2; S400 p. 3). Space heaters and electric blankets too. And a warm sensor isn’t warm water: the tub would still be below 40°F.

• Towels or blankets around the pump. The manuals don’t mention wraps, so this is my safety call, not a manual rule: the pump has a thermal cut-out for heat and direct sun, and the 2024 recall was about overheating. I wouldn’t box it in.
• “Unplug it for 10 minutes.” The restart depends on 43°F water, not on a timer. A replug only works as a test once the water is warm (Bestway’s FAQ).

Does E03 in freezing weather mean Freeze Shield isn’t working?

On a Freeze Shield pump, treat it as a warning. The 2020 manuals say the heater “must always be on” below 42.8°F, with Freeze Shield holding the water at 42.8-50°F (6-10°C) so the pipes don’t freeze, and that “alarms will pop up on the spa” if it isn’t working (AirJet Plus pp. 5, 17; AirJet pp. 4, 20). The S400 manual is blunter: “If any alarms appear on the display, the Freeze Shield™ system isn’t working” (p. 13).

My reading: E03 on a full, plugged-in tub with the heat on means the water has left that band and is within 8°F of freezing. I’d check (my list, not the manual’s) that the heater is really on, not off or on the timer, and that the tub hasn’t lost power. If it won’t hold, drain it (route 4). And don’t use the spa once the air reaches 14°F (-10°C) (AirJet Plus p. 17).

The Coleman 90363 manual has no Freeze Shield. It gives two separate warnings: the spa “should not be setup or left out in temperatures lower than 40°F (4°C)” (p. 3), and “Please do not use the spa when ambient temperature is lower than 39°F (4°C)” (p. 4). If cold weather is behind its E03, the air is likely near or past those limits (my reading), and a 43°F restart doesn’t make outdoor use at 40°F OK: drain and store it (“Freezing can severely damage the spa,” p. 10). Bestway’s FAQ is stricter: without Freeze Shield, it doesn’t recommend use below 10°C/50°F outside.

Not sure which you have? Search your manual for “Freeze Shield”; not every Coleman is a 90363. More in Freeze Shield explained and the winter guide.

Why does my SaluSpa show E03 when the water isn’t cold?

Then it’s most likely the thermometer, the manuals’ second reason. Bestway’s FAQ test: unplug the pump and plug it back in; “If the pump still displays E03, then the temperature sensor is broken.”

That’s Bestway’s job. The 2020 manuals send you to “the support section on our website” (AirJet Plus p. 25), the Coleman manual to Bestway After Sales (p. 8; its 2017 warranty gave the heater pump 360 days, p. 12). Start at Bestway USA’s customer support page with the model number from your pump’s label.

Some online answers suggest testing the sensor’s resistance or fitting one bought online. The manuals give you neither job, and the Coleman warranty excludes “improper wiring or testing” (p. 12). The sensor sits inside a mains-powered pump-heater: a support call, not DIY. Same for E05 (thermometer connections), which the 2020 and Coleman manuals send straight to support.

How is E03 different from E02 and E04?

Per the 2020 and Coleman manuals (the S400 adds steps for E04 and E05):

Cold can also bring E02: Bestway’s blog lists “It’s too cold outside to set up your hot tub” among its causes. The thermal cut-out is E08 on the 2020 pumps and E06 on the Coleman; every code is in the SaluSpa error codes guide.

FAQ

Why does my brand-new SaluSpa show E03? Probably cold fill water: the 2020 manuals want it above 42.8°F (6°C), or “the E03 alarm will appear” once the heater starts (AirJet Plus p. 11). Some owners report E03 on brand-new units. Setting one up in the cold? Check your model first.

Will E03 go away on its own? The manuals don’t say so. Their fix: unplug, and restart once the water reaches 43°F. Every other reset, by pump: how to reset a SaluSpa.

Why did E03 show up overnight? The water dropped below 40°F. In my reading, the heater was off or on the timer, the power went out, or the cold outran it. The manuals don’t say what the pump does after a power cut, so check its settings once power is back.

Can I get in the tub while E03 is showing? No. Bestway’s FAQ: “DO NOT USE THE SPA if this is displayed.”

Is E03 the same on a Lay-Z-Spa? Not necessarily. Bestway’s UK web pages aren’t manuals for U.S. pumps, and they don’t agree with each other: lay-z-spa.co.uk says E03 means “the ambient air temperature is too low,” bestwaystore.co.uk that it shows “if the water or ambient air temperature reaches above 50°c.” Their fixes are for those pumps, so go by your own pump’s manual.

Did you clear an E03? Tell me what your thermometer read and what worked. Owner reports are how this page gets better.

Jake Weber — Jake Weber is the pen name of Rookie Spa’s editor. I don’t sell spas or chemicals, and I’m not affiliated with any brand. Every guide here starts from the manufacturer’s manual, is cross-checked against the questions and fixes owners report most often, and is written in plain English for first-time owners — with a clear warning whenever something involves electricity or water safety.