Gecko spa pack error codes

Short answer

Gecko packs show a short code that alternates with the water temperature. FLO means no water flow while the main pump runs, HL a high-limit trip at 119°F inside the heater, OH spa water at 108°F, and Prr a fault in the temperature probe.

Updated October 2026By the HotTubFinder research desk

A hot tub control panel showing an error code, and the owner's manual, which names the control system — The panel shows the code. Its label is often the spa's brand, so check the manual for the control system.

What you can check yourself

Open any closed valves and jets.
Check the water level and top it up to the line in your manual.
Clean the filter, or replace it if it is worn.
Purge an air lock the way your owner's manual describes.

Where the owner's part ends

Anything else: turn off power at the breaker and call a technician.

Gecko's next steps (unions, cables, the heater, the board) are inside the equipment bay. Turn off power at the breaker and call a technician for those.

Gecko Y series (in.yj, in.ye, in.yt) and in.xe error codes

7 codes

Gecko Y series (in.yj, in.ye, in.yt) and in.xe error codes
Code	What it means	What to do
FLO	No water flow detected while the main pump runs. Gecko's guide lists 18 GPM as the minimum flow.	Check first Open any closed valves and jets. Check the water level and top it up to the line in your manual. Clean the filter, or replace it if it is worn. Purge an air lock the way your owner's manual describes. Call if it persists; the next steps are inside the equipment bay.
HL	Water inside the heater reached 119°F (48°C) and the high limit tripped. The heater body may be very hot.	Stay out Stay out of the water. Take the cover off so the water can cool. Clean the filter, or replace it if it is worn. Open any closed valves and jets. Call if it trips again after one power reset.
OH	Spa water reached 108°F (42°C). Gecko lists hot weather and long filter cycles as causes.	Stay out Stay out of the water. Take the cover off so the water can cool. Call if it returns once the water has cooled.
Prr	A problem with the regulation (temperature) probe.	Technician Call for service.
AOH	The air inside the spa skirt is too hot, pushing the control's internal temperature past its limit.	Technician Call if it does not clear once the equipment area cools.
UPL	The control has no low-level configuration loaded and cannot run.	Technician A technician reprograms it.
Hr	An internal hardware error (in.xe only).	Technician Call if it comes back after one power reset.

What does FLO mean on a Gecko pack?

The pack expects water moving through the heater and does not see it. On Y series packs the heat.wav heater carries Gecko's in.flo dry-fire protection, an electronic check that replaces the old flow switch. Gecko's guide sets the minimum at 18 gallons a minute and starts with the valves, the water level and the filter, then trapped air. Older MSPA packs used a pressure switch: FLO meant no pressure with the pump on, and FLC meant pressure with the pump off.

See FLO and flow errors on every system and how to clean a hot tub filter.

What should I do about HL or OH?

Stay out and let the water cool. Both mean too much heat, measured in different places: OH is the spa water at 108°F (42°C) and HL is the water inside the heater at 119°F (48°C). Gecko's guide starts both by checking the real water temperature with a digital thermometer. For OH in hot weather it suggests taking the cover off and shortening filter cycles, since pumps add heat as they run. When HL shows but the water itself is normal, the guide looks for something blocking flow through the heater: a dirty filter or a closed valve.

Gecko in.k1000 color keypad error messages

21 codes

Gecko in.k1000 color keypad error messages
Code	What it means	What to do
HL	Panel: High Limit circuit has trippedThe heater's high-limit safety circuit has tripped.	Stay out Stay out of the water. Take the cover off so the water can cool. Clean the filter, or replace it if it is worn. Call if it trips again.
FLOAlso: FLO - L01, FLO - L02	Panel: FLO conditionA no-flow condition. Gecko's own list says to check the filter, pump, blockage, air lock and water level.	Check first Clean the filter, or replace it if it is worn. Check the water level and top it up to the line in your manual. Open any closed valves and jets. Purge an air lock the way your owner's manual describes. Call if it persists.
NO FLO	Panel: Persistent NO FLO, all offThe no-flow condition persisted and everything has been shut off.	Check first Clean the filter, or replace it if it is worn. Check the water level and top it up to the line in your manual. Open any closed valves and jets. Purge an air lock the way your owner's manual describes. Call if it returns after the checks.
CFLO	Panel: No Flow conditionA no-flow condition.	Check first Clean the filter, or replace it if it is worn. Check the water level and top it up to the line in your manual. Open any closed valves and jets. Purge an air lock the way your owner's manual describes. Call if it persists.
FLC	Panel: The pressure switch is closedThe pressure switch reads closed when it should not.	Technician Call for service.
OH	Panel: Spa temperature is too highThe spa water is too hot.	Stay out Stay out of the water. Take the cover off so the water can cool. Call if it returns once the water cools.
Pr	Panel: Temp probes or detection circuit are defectiveOn this keypad, Pr is a probe fault, not priming.	Technician Call for service.
AOH	Panel: Elevated internal temperatureThe control's internal temperature is high.	Technician Call if it persists.
HR	Panel: A hardware error was detected (relay stuck)A relay appears stuck.	Stay out Stay out of the water. Call for service.
Hr	Panel: Hardware error was detected (thermal fuse)A thermal fuse fault.	Technician Call for service.
SP in	Panel: Input voltage issueThe supply voltage is out of range.	Technician Turn off power and have an electrician check the supply.
RH NC	Panel: Comm. error between in.xm2 and in.thermThe pack and the heater module are not talking.	Technician Call for service.
RH ID	Panel: in.xm2 and in.therm incompatibleThe pack and heater module do not match.	Technician Call for service.
SC ER	Panel: Error detected during the learning modeSetup (learning mode) failed.	Technician Call for service.
F1, F2, F3	Panel: in.xm2 fuse is blownFuse 1, 2 or 3 on the pack has blown.	Technician Turn off power at the breaker and call for service.
ER1	Panel: Swim spa config: slave unit is missingOn a two-pack swim spa, the second pack is not found.	Technician Call for service.
UPL	Panel: The spa pack does not have valid softwareNo valid software on the pack.	Technician A technician reprograms it.
HiBr, LoBr, NoBr	Panel: Bromine level messagesFrom the built-in bromine system: HiBr asks for fresh water, LoBr and NoBr ask for more of the system's bromine salt.	Normal Nothing to do: this is the spa working as designed. Follow the bromine system's manual.
Comm	Panel: Verify cable connectionsThe keypad has lost contact with the pack.	Technician Cable checks are inside the equipment bay: call for service.
Supp	Panel: Connect power cord to 240 V sourceThe pack wants a 240 V supply.	Technician Have an electrician check the circuit.
HP1 to HP99	Panel: Heat pump error, service codeA heat pump fault, numbered 1 to 99.	Technician Contact your dealer with the number.

What do the codes on older Gecko packs mean?

Older MSPA and SSPA packs used a few codes of their own. Prh is a fault in the high-limit sensor, FrE is freeze protection running, and CLFL is a reminder to clean the filter after 14 days of running. SSPA packs without a text display flash three dots instead.

Gecko MSPA and SSPA pack codes (older systems)

9 codes

Gecko MSPA and SSPA pack codes (older systems)
Code	What it means	What to do
FLO	No pressure at the pressure switch while the pump runs. A dirty filter or anything limiting flow can cause it. Packs from 1998 on switch the heater off.	Check first Clean the filter, or replace it if it is worn. Check the water level and top it up to the line in your manual. Open any closed valves and jets. Call if it persists after the checks.
FLC	The pressure switch reads pressure while the pump is off.	Technician Call for service.
Prr	A fault with the temperature regulation probe. From 1998 on, the pack ignores it for an hour while the water warms past 34°F (1°C).	Technician Call for service.
Prh	A fault with the high-limit sensor on the heater.	Technician Call for service.
HL	A high-limit fault. It blinks when the water itself reads 112°F (44°C) or more; a steady display points to the high-limit sensor or heater.	Stay out Stay out of the water. Take the cover off so the water can cool. Clean the filter, or replace it if it is worn. Open any closed valves and jets. Call if it does not clear.
FrE	Freeze protection is running.	Normal Nothing to do: this is the spa working as designed.
CLFL	Clean-filter reminder after 14 days of running (packs from 1998 on).	Normal Clean the filter, or replace it if it is worn.
Three flashing dots	On SSPA packs, three flashing dots mean the pack detected a problem. Gecko's card says not to enter the water.	Stay out Stay out of the water. Open any closed valves and jets. Clean the filter, or replace it if it is worn. Check the water level and top it up to the line in your manual. Turn the power off at the breaker for 30 seconds, then back on. Once. Call if it returns after one power reset.
Flashing temperature	Panel: Water temperature flashingOn SSPA packs, the water reached 112°F (44°C). It resets by itself at 109°F (43°C).	Stay out Stay out of the water. Take the cover off so the water can cool. Call if it keeps happening.

Which hot tub brands use Gecko's codes?

These manuals print Gecko's list or name Gecko equipment. Bullfrog's 2026 A Series manual reprints the in.k1000 table word for word. Within one brand, the list can change by series and year.

Which code list each brand's manual uses, by model line
Brand	Model line, what its manual shows, and the code list
Bullfrog Spas	A Series, 2026Prints Gecko's in.k1000 error list word for word, naming Gecko's in.xm2 pack.Code list: Gecko in.k1000 color keypad
Master Spas	Legend Series, 2026Gecko in.k1000+ keypad; adds VMS pump service codes.Code list: Gecko in.k1000 color keypad
Cal Spas	Models with Gecko equipment, 2026Gecko error list (FLO, HL, OH, Prr, AOH, UPL).Code list: Gecko in.k1000 color keypad
Cal Spas	Platinum, 2026Gecko in.k1000 error list.Code list: Gecko in.k1000 color keypad
American Whirlpool	2026 modelsGecko in.k1000 and in.k500 keypads; Prr, AOH, Hr, HL, FLO, OH.Code list: Gecko Y series and in.xe packs

Common questions

How do I reset a FLO error on a Gecko hot tub?

Fix the flow first: open the valves, top up the water, clean the filter and purge any air lock. The code clears when the pack sees flow again. If it stays, the next checks are inside the equipment bay, so call a technician.

What does HL mean on a Gecko spa pack?

The high limit tripped: water inside the heater reached 119°F (48°C) on Y series and in.xe packs. Stay out of the water. Gecko's guide first compares the display with a digital thermometer, then looks for a blocked filter or closed valve.

What is the difference between OH and HL on Gecko?

OH is the spa water at 108°F (42°C). HL is the water inside the heater at 119°F (48°C). For OH, Gecko's guide looks at hot weather and long filter cycles; for HL with normal water, at something blocking flow through the heater.

What does Prr mean on a hot tub?

On Gecko packs, a problem with the temperature regulation probe. It needs a technician. On Gecko's in.k1000 color keypad the same fault shows as Pr.

What does AOH mean on a Gecko hot tub?

The air in the equipment area is too hot and the control is heating past its limit. Hot Spring's FreeFlow manual, which prints the same code, gives 194°F (90°C) in the compartment.

Sources

Gecko troubleshooting guide, Y series and in.xe (9919-101313-D) geckoalliance.com · checked October 2026
Gecko in.k1000 techbook, error messages geckoalliance.com · checked October 2026
Gecko MSPA-1-AX spa pack service manual geckoalliance.com · checked October 2026
Gecko SSPA-1-AX quick reference card geckoalliance.com · checked October 2026
Gecko Y series techbook geckoalliance.com · checked October 2026
Hot Spring FreeFlow Collection owner's manual, 2026 d1oxc6ayqrhsgs.cloudfront.net · checked October 2026
Bullfrog Spas A Series owner's manual, 2026 (v1.9) bullfrogspas.com · checked October 2026
Master Spas Legend Series owner's manual, 2026 masterspascdn.com · checked October 2026
Cal Spas Patio and Patio Plus owner's manual, Gecko equipment, 2026 calspas.com · checked October 2026
Cal Spas Platinum owner's manual, 2026 calspas.com · checked October 2026
American Whirlpool owner's manual, 2026 americanwhirlpool.com · checked October 2026

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