Arctic Spa Error Codes: HL, FLO, FLC, HPT, Prr & ER Codes

Quick answer: most Arctic Spa error codes point to a flow, temperature, heater, probe/sensor, SpaBoy/water-chemistry, or current/communication problem. Before replacing parts, turn the spa off at the breaker, wait 20–30 seconds, turn it back on, and see if the code returns. If the same code comes back, use the tables below to decide whether it is a simple water/filter check or a technician-level repair.

This guide covers both newer 2020+ Custom Series numbered ER codes and older/Core/Classic topside messages like HL, FLO, FLC, HPt, Prr, Hd, pH, and GF.

Contents

1 Quick Arctic Spa error code lookup
2 Newer 2020+ Custom Series ER codes
3 Older/Core/Classic Arctic Spa topside codes
4 Flow errors: FLO, FLC, ER 00 and ER 01
5 Temperature errors: HL, OH, ER 02, ER 03 and ER 05
6 Probe and heater errors: Prr, Hd, HPt, ER 04, ER 09 and ER 10
7 SpaBoy and water chemistry codes
8 When to reset the breaker vs call a technician
9 Source notes
10 Arctic Spa error code FAQs
11 Related Arctic Spa owner guides

Quick Arctic Spa error code lookup

Code family	What it usually points to	First checks	Stop and call a technician when
FLO / ER 00	No water flow through the heater	Water level, valves, pump operation, dirty filters	Flow is still missing after water/filter checks
FLC / ER 01	Flow switch fault	Power reset, water level, stuck/failed switch symptoms	The switch keeps reading incorrectly
HL / ER 02 / ER 03 / ER 05	High-limit, heater temperature, or spa over-temperature	Power reset, remove cover, check flow/filter restriction	Water is too hot, code returns, or heater keeps overheating
HPt / Hd / Prr / ER 04 / ER 09 / ER 10	Temperature or heater probe issue	Reset power and inspect for obvious loose probe connection if accessible	A probe/sensor likely needs diagnosis or replacement
pH / ER 08 / ER 15	SpaBoy or water chemistry reading	Test water with strips and adjust pH gradually	Readings do not match, stay unstable, or SpaBoy hardware is suspected
CLE	Cleaning/filter reminder	Clean or replace filter media	It appears with flow/heater errors after filter cleaning

If the code is flow-related, dirty or restricted filters are one of the first things to rule out. See our guide on cleaning Arctic Spa Pro filters. If you are tired of fighting expensive proprietary filters, the Spa Filter Adapter Kit v3 lets compatible 2020+ Arctic Spas Custom Series tubs use easier-to-rinse generic replacement filters.

Newer 2020+ Custom Series ER codes

After Arctic Spa software version 1.0.64, many error messages changed from short abbreviations to numbered ER codes. For example, the topside may show ER 00, ER 01, or ER 02 instead of only showing the older abbreviation.

Error code	Abbreviation	Error name	What it means	First troubleshooting step
ER 00	FLO	No Flow	Flow switch open. No water is flowing through the heater when pump 1 is on.	Reset power, verify water level, make sure valves are open, and clean/check filters. If it returns, pump or flow-switch diagnosis may be needed.
ER 01	FLC	Flow Switch	Faulty or stuck flow-switch reading.	Reset power. If the code comes back, contact a qualified technician.
ER 02	HL	Heater Over Temperature	The heater has reached about 119°F.	Reset power once. If it returns, stop using the spa and have the heater/flow system checked.
ER 03	HL(F)	Spa Over Temperature	The spa water is hotter than the set temperature.	Remove the cover and let the water cool. Do not enter overheated water.
ER 04	Prr	Spa Temperature Probe	The spa water temperature probe is disconnected, faulty, or not reading correctly.	Reset power. If accessible, a technician can check the probe connection; replacement may be needed.
ER 05	HL	High Limit	The heater is too hot and has reached about 118°F.	Reset power once. If it returns, check for flow restriction and call a technician.
ER 06	EE	EEPROM Error	Read/write memory fault.	Reset power. If the error remains, contact a qualified technician.
ER 07	FP	Freeze Protect	The spa water is very cold and the spa is circulating water to protect against freezing.	Let the spa heat safely. Do not interrupt freeze-protection behavior unless advised by a technician.
ER 08	pH	pH High	pH is reading high, commonly above about 8.5.	Test with strips and adjust down gradually. See our chlorine and pH guide.
ER 09	Hd	Heater Probe Disconnected	The heater temperature probe is disconnected or not reading correctly.	Reset power. If it returns, the probe connection or probe itself needs diagnosis.
ER 10	HPt	Heater Probe Test Failed	The spa failed the startup heater probe test.	Reset power. If it returns, have a technician inspect the heater probe and control system.
ER 11	SB-CE	SpaBoy Communication Error	SpaBoy is not communicating with the motherboard.	Reset power. If it returns, SpaBoy wiring/hardware needs technician diagnosis.
ER 12	H/S cal	Heater/Spa Temperature Calibration	The spa and heater temperature readings do not agree when they should.	Reset power. If it returns, probe calibration or replacement may be needed.
ER 13	H-wo-s	Heater Way Above Spa Temperature	The heater temperature is much higher than the spa temperature, often from restricted flow.	Open jets/valves, check water level and filters. If it returns, call a technician.
ER 14	orp_nr	SpaBoy ORP Not Responding	SpaBoy is not seeing the expected ORP change during production.	Check salt/water balance. If water chemistry is normal, SpaBoy probe or generator diagnosis may be needed.
ER 15	Ph_L	pH Low	pH is low, commonly below about 6.5.	Test the water and adjust pH up gradually.
ER 20	P1Lnc	Pump 1 Low No Current	Pump 1 is not drawing current on low speed.	Reset power. If it returns, contact a qualified technician.
ER 21	P1Hnc	Pump 1 High No Current	Pump 1 is not drawing current on high speed.	Reset power. If it returns, contact a qualified technician.
ER 22	P2nc	Pump 2 No Current	Pump 2 is not drawing current.	Reset power. If it returns, contact a qualified technician.
ER 23	P3nc	Pump 3 No Current	Pump 3 is not drawing current.	Reset power. If it returns, contact a qualified technician.
ER 24	SDSnc	SDS Pump No Current	The SDS pump is not drawing current.	Reset power. If it returns, contact a qualified technician.
ER 25	YESSnc	YESS No Current	The optional YESS system is not drawing current.	Reset power. If it returns, contact a qualified technician.
ER 26	Onnc	Onzen No Current	The Onzen salt-water system is not drawing current.	Reset power. If it returns, the cell or internal electrical system may need service.
ER 27	H1nc	H1 No Current	Heater 1 is not drawing current.	Reset power once. If the code returns, stop troubleshooting and contact a qualified technician.
ER 28	H2nc	H2 No Current	Heater 2 is not drawing current.	Reset power once. If the code returns, stop troubleshooting and contact a qualified technician.

Older/Core/Classic Arctic Spa topside codes

Older Arctic Spa, Core Series, Classic Series, and some topside displays may show the abbreviation directly instead of a numbered ER code. The exact wording varies by model and software version, but these are the common meanings.

Display code	Plain-English meaning	First checks	When to call for service
Prr	Temperature probe problem or disconnected temperature probe.	Reset power once.	If the code returns, the probe or board connection should be checked.
HL	High-limit / heater barrel too hot, or flashing over-temperature warning.	Do not enter overheated water. Remove cover, allow cooling, check flow/filter restriction.	If HL returns or the water/heater is overheating.
FLO	No flow detected while the pump should be moving water.	Water level, valves, pump operation, dirty/restricted filters.	If flow is still not detected after simple checks.
FLC	Flow switch closed/stuck when it should not be.	Reset power once.	If the flow switch continues to read incorrectly.
HPt	Heater probe test failed.	Reset power once.	If it returns during startup.
Hd	High-limit/heater probe disconnected.	Reset power once.	If the probe is disconnected or the code repeats.
pH	SpaBoy pH reading high or low depending on model/software.	Confirm with test strips and adjust gradually.	If readings are unstable or hardware is suspected.
GF / GFI	Ground fault or suspected short to ground.	Do not keep resetting repeatedly.	Call a qualified technician/electrician.
tSt	Startup test checking whether the hi-limit probe is attached.	Wait during startup.	If the test fails or leads into another probe code.
OH	Water over-temperature.	Do not enter the water. Remove cover and allow cooling.	If temperature remains unsafe or the code returns.
AOH	Cabinet/skirt internal temperature too high.	Open the skirt area if safe and allow cooling.	If it does not clear or components are overheating.
Hr	Internal spa pack/system error.	Reset power once.	If it returns, contact a dealer or service supplier.
OtH	Heater barrel heating too quickly.	Check water flow and filter restriction.	If the heater continues to overheat.
LocP / LocF	Topside controls partially or fully locked.	Check the topside lock setting/manual.	If the keypad will not unlock normally.
FrEEzE ProtEct	Freeze-protection mode.	Let the spa protect itself and heat safely.	If normal heating/circulation does not resume.
CLE	Cleaning/filter reminder, not usually a hard failure by itself.	Clean or replace filter media.	If it appears alongside flow/heater errors after the filter is clean.

Flow errors: FLO, FLC, ER 00 and ER 01

Flow errors are some of the most common Arctic Spa codes. Start with the easy checks first:

Make sure the water level is high enough.
Confirm valves are open and jets are not overly restricted.
Check whether pump 1 is actually running.
Remove and clean the filters, then test again.
Look for air lock symptoms after draining/refilling.

If the code clears with the filters removed or freshly cleaned, the issue may be filter restriction. If it returns even with clean filters and proper water level, the flow switch, pump, wiring, or control system may need professional diagnosis.

Temperature errors: HL, OH, ER 02, ER 03 and ER 05

High-limit and over-temperature errors should be treated seriously. Do not enter water that may be overheated. Remove the spa cover, let the water cool, and check for flow restriction before running the spa normally again.

If an HL or heater-over-temperature code returns after a reset, do not keep cycling the breaker over and over. Repeated overheating points to a real flow, heater, probe, or control issue.

Probe and heater errors: Prr, Hd, HPt, ER 04, ER 09 and ER 10

Probe and heater test errors usually mean the spa cannot trust one of its temperature readings. A reset is fine as a first check, but repeated probe errors usually need a technician to inspect the probe connection, wiring, or sensor itself.

SpaBoy and water chemistry codes

SpaBoy and pH/ORP-related messages can be caused by water balance, salt levels, probe condition, or SpaBoy hardware. Always confirm water readings with test strips instead of relying only on the display. For water testing basics, read our guide to checking chlorine and pH levels in Arctic Spa hot tubs.

When to reset the breaker vs call a technician

A single reset is a reasonable first step for many Arctic Spa error codes. But the breaker reset is not a magic eraser. If the same code returns, the spa is telling you something is still wrong.

Usually safe to check first	Better left to a technician
Water level	Heater current faults
Dirty or clogged filters	Ground fault / GFI / electrical shorts
Closed valves or restricted jets	Probe replacement or board-level diagnosis
pH/chlorine testing and normal water balance	Repeated high-limit/over-temperature faults
Letting overheated water cool with the cover off	Pump current faults that return after reset

Source notes

This guide is based on Arctic Spa owner troubleshooting patterns, filter/flow experience, and publicly available Arctic Spas manual/error-code references, including Arctic Spas’ official topside error code guide, Custom Series manual page, and Core Series manual page. SpaFilterAdapter.com is not affiliated with, endorsed by, or approved by Arctic Spas.

Arctic Spa error code FAQs

How do you reset an Arctic Spa error code?

Turn the spa off at the breaker, wait about 20–30 seconds, then turn it back on. If it was a false or temporary code, it may clear. If the same code returns, use the code table and troubleshoot the actual cause instead of repeatedly resetting the breaker.

What does HL mean on an Arctic Spa?

HL is a high-limit or over-temperature warning. It can mean the heater or water temperature is too high. Do not enter overheated water. Remove the cover, let the spa cool, check for filter/flow restriction, and call a technician if the code returns.

What does FLO mean on an Arctic Spa?

FLO means the spa is not detecting proper water flow while the pump should be moving water. Check water level, valves, pump operation, and dirty or restricted filters first.

What does FLC mean on an Arctic Spa?

FLC usually means the flow switch is reading closed when it should not be. Reset power once. If FLC returns, the flow switch or related wiring may need service.

What does HPt mean on an Arctic Spa?

HPt means the heater probe test failed. A reset is fine as a first check, but if the code returns during startup, have a qualified technician inspect the heater probe and related system.

What does Prr mean on an Arctic Spa?

Prr points to a temperature probe problem. The probe may be disconnected, faulty, or not reading correctly. If the code returns after a reset, the probe or board connection should be checked.

Why does my Arctic Spa keep showing flow errors?

Repeated flow errors are commonly tied to low water level, closed valves, air locks, weak pump flow, dirty filters, or a faulty flow switch. If clean filters and proper water level do not solve it, it is time for service.

Are Arctic Spa error codes different on 2020+ Custom Series tubs?

Yes. Newer 2020+ Custom Series spas often show numbered ER codes, while older/Core/Classic displays may show abbreviations like HL, FLO, FLC, Prr, HPt, and Hd. The numbered codes often map back to those same underlying fault families.

Arctic Spa Error Codes: HL, FLO, FLC, HPT, Prr and ER Codes