Common Hot Tub Error Codes

Thursday, 30th Mar 2023 in Maintenance, Uncategorised
Common Hot Tub Error Codes Feature Image | A6 Hot Tubs

Hot tubs can be complicated things, especially when they throw up a couple of error codes. Whether it is a Balboa error code or just a common hot tub error code, we are here to help. In this blog, we have listed most of the commonly shown error codes that you may find displayed on your control panel. If you need further help or would like an engineer to come out then contact us. Take a look at our list of error codes below and see if they can help get you back in the water and enjoying your hot tub again.

Hot Tub Error List
—- or — Message ERROR CODE

This hot tub error or warning code is letting you know that the current water temperature is “unknown”. This usually occurs whilst the hot tub is in sleep mode or economy mode. To find out the current hot tub water temperature simply turn on the heat-related pump and wait a few moments or change the setting to a standard heating mode.

DY/DRY or Heater dry service reqd ERROR CODE

The DY hot tub error message could be telling you a few things, it is basically highlighting that your heater is dry and therefore you may have issues with your water levels. Your water level may be too low to start the heater so to avoid the hot tub damaging itself it will not heat up. Start by checking your water levels and then attempt to reset, if the error still occurs check for flow restrictions, closed valves, airlocks and ensure the pump has been primed. If this still does not resolve it then contact your local vetted hot tub service team.


This hot tub warning code is letting you know that it is too cold, and a potential freeze condition may occur. In these circumstances, it is best to ensure your tub will not freeze either by running it and keeping the water temperature warm or to winterise it to prevent damage. If the weather is not cold and you are receiving this message, then you may have a faulty temperature sensor.

PR or Priming Mode HOT TUB CODE

This is not an error code, it appears when the hot tub has just been turned on and it is getting itself ready by priming pumps, etc. Simply wait 4 mins and it should be good to go. During this time, you can turn on the pumps and blowers to remove air from the heater. No automatic functions will occur during these 4 mins. If you have a GL or EL system with a mode button, this can be used to turn on the Ozone for 15 seconds.


The SLP or SL message will be visible when the hot tub is in sleep heating mode, it will often appear alternately with the water temperature. If no temperature is shown, then the hot tub is between filter cycles.


This hot tub code is letting you know that your hot tub is running in economy mode. If your hot tub is in economy mode during a filter cycle it is unlikely to be at the desired temperature currently.

—C, —F or —Message

The Actual Water Temperature is “Unknown” (- -). This is a normal function; the hot tub has exited Priming Mode but the pump has not yet run for at least 1 or 2 and therefore has not tested temperature. Leave for a few moments and the code should disappear.

SbY or Standby Mode

Standby mode will allow you to perform functions such as cleaning or replacing a side filter cartridge without the pumps and blower turning on. To exit this mode simply press any button except ‘jets1’.


This means there is a flow issue with your heater. The tub may have detected a substantial difference between the temperature sensors that indicate that water is not flowing properly through the heater.

LF or Low Flow

This code will appear after the HFL code has been shown 5 times and it indicates persistent flow issue. This could be due to a few things. Firstly, check all the below conditions and then attempt to restart the heater. If this fails, please contact a registered hot tub service provider.

  1. Dirty filter
  2. Low water levels
  3. Pump not primed
  4. Pump not running
  5. Blocked suction fitting
  6. Blocked skimmer
  7. Closed slice valve
  8. Too many closed jets

SnA, SA or Sensor A service reqd

If the SnA code appears please do not enter your hot tub as this could be an indicator that the water is an exceptionally high temperature. The Sensor A connector on the board may have failed and might need replacing.

Std , St or Standard

This code is not an error, it will appear for a few seconds whenever the heating mode changes to standard from a different mode.

Other Common Hot Tub Error Codes

The following common hot tub error codes cover brands such as: Gecko Electronics, Balboa Instruments, Hurricane, Sundance Spas, Hercules, Brett Aqualine, Splash Pool Accessories, Vita, Spaquip, Ampac, Onga, Dimension One, Sweetwater, and many more.

Error CodeDescription
BJ2PHi-Limit – water temp too high
C4.4Hi- Limit
Cd, CLdFreeze Condition
CE 01Stuck Touchpad button
CE 02No controller Data Communication
CE 03Temperature sensor fault
CE 04Water Sensor/Pressure switch fault
CE 05Over Temperature Condition
CE 06High Limit manual reset Klixon tripped
CE 07Stuck Relay
 CE 08Temp Sensor Fault -( Spaquip Digital 2000 MK1 sensor)
CE 09Water Prime Fault – Lack of water
CoLdspa heater temp below 40F
Cool, COOL, COLWater is 11C below-set point – not a fault
DR, dr, dy, DRYHeater dry – insufficient water fault
Er0, Er1Temperature sensor faulty
Er2, Er3Hi-Limit fault
Er4Flow/Pressure switch short circuit
Error 3 – SpaquipStuck touchpad button
Error 4Water sensor fault
Error 5Over-temperature
Error 6Klixon Tripped – over temp
Error 7Stuck Relay
Error 8Temperature sensor fault
ErrSoftware Program Fault
E###pH probe out of calibration
E0Short circuit temperature sensor
E1Open circuit temperature sensor
E2short circuit/closed high limit sensor
E3Open circuit high limit sensor
E4Short circuit/closed pressure/flow switch
E7Improper electrical connection
 FLO, Flo, FL1Flow/pressure switch open circuit
lack of flow or pressure or for Sundance/Spa Builders/Balboa
Flow switch is closed circuit
 FLC, FL2Flow/pressure switch closed-circuit
debris in the switch 
perforated diaphragm, faulty
FLPressure/flow switch failure
 FLO (flashing)Flow switch open circuit – Sundance/Spa Builders/Balboa
FrE, Fr, FPFreeze Condition
HiLi, HLErWater temperature above the acceptable range
 HL, HFL, HH, OHHHigh limit sensor reading 45-48C, or above – check the flow
HoldPanel buttons pressed too many times too quickly
HOTPCB thermistor above 82C
HPElectronic controller error
H2OWater Prime Fault – lack of water
ICE, ICFreeze Condition
 ILOCInterlock failure
also caused by faulty ozonators, pumps, and equipment
LEHTemperature Sensor Fault
LFLow Flow Fault
LOFreeze Condition
LOCControl Panel functions Locked
 LS=0, LS=SMultiple causes
open-circuit sensor
faulty panel connection
improper voltage, etc
L1Panel Lock
L2Panel Lock
OH, OHS, oHOverheat Condition 43-45C
OPOpen circuit sensor
PPower overload – excess current draw
pd, PdRunning on battery – power supply interrupted
 PLUGSundance/Spa Builders 
Service Technician’s Test Plug accidentally left connected to PCB
 PnL, PnlCommunication disrupted between touchpad and PCB
PrSystem Priming – not a fault
PrhHigh-limit sensor fault
PrrTemperature sensor fault
PSFlow/Pressure switch failure
 PSoC, PSoL, PSoHPressure switch open circuit with Circulating, LowSpeed, or High-speed pumps
SA, SnA, SnH, Sb, Snb, SntSensor Open Circuit or faulty – SnH – Hi-Limit, SnT – Temp sensor
SEoPSensor Open Circuit
SESHSensor Short Circuit
SHShort circuit sensor
Sn, SnSSensors out of balance
Sn1High Limit sensor fault
Sn2, Sn3Temperature sensor fault
 SS=0, SS=SMultiple causes – open circuit sensor, faulty panel connection, improper voltage, etc.
ToETime Out Error
0.0 or 56Open/Closed-circuit faulty temperature sensor
000Programming Error
 Or ** (2.5-9)Over Range beyond permissible temperature – Programming Error
– 01Hi-Limit
– 02Temp sensor fault
– 03Flow/pressure switch open
– 04Flow/Pressure switch closed
– 07Hi-limit
 – –Temperature unknown
displayed at power-up for 2 minutes
– not a fault
 – – – – , – – –Sundance/Spa Builders – ‘Watchdog’ – 48C reached, electronic fault, shuts the system down.
Major Fault
* * * (3 flashing dots under temp display) Flow/Pressure switch either Open or Closed Circuit
* * * (as above, plus illuminated red LED on PCB) High Limit Fault

Flashing Light Errors

Some errors may not appear as codes on your hot tub. This can be due to the fault or the control panel in question. Some hot tubs and control panels will display errors through flashing lights and noises on the control panel. Some of the most common flashing light error codes on hot tubs can be seen below.

Flashing LightErrors Description
3 flashing dotsFlow Error – FLO or FLC
3 flashing dots and PCBSame as OH
LED illuminated 
1 flash – 3 second gapHigh Limit fault
2 flashes – 3 second gapPressure/Flow switch short circuit
3 flashes – 3 second gapPressure/Flow switch open circuit
4 flashes – 3 second gapOpen circuit Sensor(s)
Flash – 1 second on, 1 second off Same as OH
Flash – briefly OFF once per second Same as Sn1 or Sn3
Flash – briefly ON once per second Same as FLC
Blinking Power IndicatorLight – Hydromate High Limit tripped or, sensor fault
1 flash per second – onga 4352, 53, 95, etcPressure switch open circuit – could also be motor or motor thermal overload
3 flashes per second – onga 4352, 53, 95, etcElectronic fault – element sensor (most common cause) or PCB
Green flashes – SpaquipPulsar/2095 series Water sensor fault – lack of water
Red/Green alternate flashesTemperature sensor fault, open circuit, or high limit tripped – push Reset Rod

We’ve now come to the end of the read and hopefully, this is of common hot tub error codes has helped. If your problem hasn’t been resolved or identified by the codes shown, we recommend contacting a professional for help. If you want some help from one of our engineers we offer a range of hot tub services and would recommend a fault find service. You can see the services we offer in this past post.

Common Hot Tub Error Codes FAQs

Why will my hot tub not stay hot?

There are numerous reasons why a hot tub is not heating up such as a faulty heater, circulation pump, broken thermostat or there is not enough water in the hot tub. If your heater can only heat the water when the hot tub is not in use then it could be that you need a larger heater, also many spas turn the heater off when the jet pumps run. Consult with your supplier or seek advice if your heater is not working properly.

Can you put soap into a hot tub?

We know the idea of bubbles in a hot tub may seem like a great idea, however, they will soon overflow and cause mayhem, also the use of detergents builds up scum and bacteria inside pipes. We recommend showering before using a hot tub to reduce the risk of detergent contaminants entering your tub and causing unwanted foam if this happens simply use foam away. If you want to add scents to your hot tub for increased relaxation, we recommend using aromatherapy spa salts.