Master Spas
Master Spas Hot Tubs & Spas Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
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BLB
Display shows BLB or bLb, and the spa light does not work.
Blower/Light Circuit Fault (varies by model)
CF
Display shows CF or CLn and prompts for filter cleaning; the spa may limit heating or run pumps more often.
Filter Maintenance Reminder / Flow Protection
COL
The display shows COL, and the spa will not heat above a low temperature setpoint.
Cold Weather Protection / Economy Mode Indication
COOL
Display shows COOL, and the water temperature is significantly below the setpoint; the heater may be limited.
Cool Water Condition / Extended Heat-Up Time
dr
The display shows dr or DR, and the heater is disabled; the spa may not heat.
Low Flow / Dry Heater Detected
dY
The display shows dY or DY, and the heater is disabled.
Dry Heater Confirmed / Severe Low Flow
FLC
The display shows FLC or FL2, and the spa may shut down the heater; sometimes pumps run continuously.
Flow Switch Closed When It Should Be Open
FLO
The display shows FLO or FL1, and the heater will not run; circulation may be intermittent.
Flow Switch or Pressure Switch Fault (Open When Should Be Closed)
HL
The display shows HL or HLo, and the spa shuts down the heater; pumps may still run.
High-Limit Trip / Localized Heater Overheat
ICE
Display shows ICE or IC, and pumps run periodically even when the spa is not in use.
Freeze Protection Mode Active
LOC
Display shows LOC or a lock icon, and buttons do not respond.
Panel Lock / Child Lock Activated
O3
Display shows O3 or OZN, and the ozone system does not appear to run.
Ozone Generator or Ozone Circuit Fault
OH
The display shows OH or OHH, and the spa shuts down; pumps may run briefly then stop, and the water feels very hot.
Overheat Condition Detected
OHt
Display shows OHt, and the heater shuts off; pumps may continue.
Heater Tube Overheat / Localized High Temperature
P1
Display shows P1 error, and Pump 1 does not operate correctly.
Pump 1 Circuit or Overcurrent Fault
P2
Display shows P2 error, and Pump 2 does not operate correctly.
Pump 2 Circuit or Overcurrent Fault
PF
Display shows PF or PFL, and the spa may randomly shut off or reboot.
Power Fault / Line Voltage Error
Prr
The display shows Prr or PR, and the spa may not heat or may shut down.
Pressure Switch Error
SE
Display shows SE or SEr, and controls may be unresponsive or erratic.
Sensor Error / Sensor Out of Range
Sn1
Control panel displays Sn1, and the spa will not heat or may shut down.
Primary Temperature Sensor Failure (Sensor 1)
Sn2
Control panel displays Sn2, and the spa may not heat correctly or shuts down.
Secondary Temperature Sensor Failure (Sensor 2 / High-Limit Sensor)
Sn3
The display shows Sn3, and the spa may shut down or ignore temperature settings.
Auxiliary / Ambient Temperature Sensor Failure
UV
Display shows UV or UVC, and the UV sanitizer indicator is off or flashing.
UV Sanitizer Lamp or Ballast Fault
— —
The display is blank or shows only dashes; the spa is not responding.
Topside Control Panel Communication Failure
Symptom
Air blower does not turn on or shuts off quickly after starting.
Air Blower Failure or Overheat Protection
Symptom
Jets are weak, or some seats have very little water pressure even though pumps run.
Hydraulic Flow Restriction / Air Control or Diverter Misconfiguration
Symptom
Loud grinding, squealing, or rattling noise from the pump area when jets are on.
Pump Motor or Wet End Mechanical Failure
Symptom
One or more jets have popped out or will not stay in place.
Jet Internal Retainer Wear or Damage
Symptom
Persistent foaming on the water surface even after rinsing filters.
Surfactant Build-Up / Water Contamination
Symptom
Pump runs, but no water comes out of the jets after draining and refilling the spa.
Air Lock in Pump or Plumbing
Symptom
Spa is leaking water inside the equipment bay or from under the cabinet.
Plumbing or Component Leak
Symptom
Spa lights flicker, some LEDs are out, or colors do not change correctly.
LED Lighting System Degradation or Driver Fault
Symptom
Spa trips the GFCI breaker immediately or within a few seconds of turning on.
Ground Fault or Short Circuit in Spa Components
Symptom
Spa water cools down quickly between uses even though the cover is on.
Heat Loss / Insulation or Cover Inefficiency
Symptom
Spa water has a strong chemical or musty odor despite normal readings.
Water Quality Imbalance / Biofilm or Contamination
Symptom
Spa will not heat; water stays cold, but pumps run normally, and no error code is displayed.
Heater Element Failure Without Code
Symptom
Spa will not turn on at all; no lights on the control panel, completely dead.
No Power to Spa / Control Pack Not Energized
Symptom
Topside control buttons are unresponsive or activate incorrect functions.
Keypad Overlay or Topside Control Failure
Symptom
Water feature (waterfall or fountain) is not flowing or is very weak.
Water Feature Flow Restriction or Valve Misadjustment
Symptom
Water seeping around one or more jets on the spa shell.
Jet Body Gasket or Locknut Leak
Symptom
Water temperature overshoots the setpoint by several degrees before the heater shuts off.
Temperature Regulation Inaccuracy
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| BLB |
Display shows BLB or bLb, and the spa light does not work.
|
Blower/Light Circuit Fault (varies by model) | View Details |
| CF |
Display shows CF or CLn and prompts for filter cleaning; the spa may limit heating or run pumps more often.
|
Filter Maintenance Reminder / Flow Protection | View Details |
| COL |
The display shows COL, and the spa will not heat above a low temperature setpoint.
|
Cold Weather Protection / Economy Mode Indication | View Details |
| COOL |
Display shows COOL, and the water temperature is significantly below the setpoint; the heater may be limited.
|
Cool Water Condition / Extended Heat-Up Time | View Details |
| dr |
The display shows dr or DR, and the heater is disabled; the spa may not heat.
|
Low Flow / Dry Heater Detected | View Details |
| dY |
The display shows dY or DY, and the heater is disabled.
|
Dry Heater Confirmed / Severe Low Flow | View Details |
| FLC |
The display shows FLC or FL2, and the spa may shut down the heater; sometimes pumps run continuously.
|
Flow Switch Closed When It Should Be Open | View Details |
| FLO |
The display shows FLO or FL1, and the heater will not run; circulation may be intermittent.
|
Flow Switch or Pressure Switch Fault (Open When Should Be Closed) | View Details |
| HL |
The display shows HL or HLo, and the spa shuts down the heater; pumps may still run.
|
High-Limit Trip / Localized Heater Overheat | View Details |
| ICE |
Display shows ICE or IC, and pumps run periodically even when the spa is not in use.
|
Freeze Protection Mode Active | View Details |
| LOC |
Display shows LOC or a lock icon, and buttons do not respond.
|
Panel Lock / Child Lock Activated | View Details |
| O3 |
Display shows O3 or OZN, and the ozone system does not appear to run.
|
Ozone Generator or Ozone Circuit Fault | View Details |
| OH |
The display shows OH or OHH, and the spa shuts down; pumps may run briefly then stop, and the water feels very hot.
|
Overheat Condition Detected | View Details |
| OHt |
Display shows OHt, and the heater shuts off; pumps may continue.
|
Heater Tube Overheat / Localized High Temperature | View Details |
| P1 |
Display shows P1 error, and Pump 1 does not operate correctly.
|
Pump 1 Circuit or Overcurrent Fault | View Details |
| P2 |
Display shows P2 error, and Pump 2 does not operate correctly.
|
Pump 2 Circuit or Overcurrent Fault | View Details |
| PF |
Display shows PF or PFL, and the spa may randomly shut off or reboot.
|
Power Fault / Line Voltage Error | View Details |
| Prr |
The display shows Prr or PR, and the spa may not heat or may shut down.
|
Pressure Switch Error | View Details |
| SE |
Display shows SE or SEr, and controls may be unresponsive or erratic.
|
Sensor Error / Sensor Out of Range | View Details |
| Sn1 |
Control panel displays Sn1, and the spa will not heat or may shut down.
|
Primary Temperature Sensor Failure (Sensor 1) | View Details |
| Sn2 |
Control panel displays Sn2, and the spa may not heat correctly or shuts down.
|
Secondary Temperature Sensor Failure (Sensor 2 / High-Limit Sensor) | View Details |
| Sn3 |
The display shows Sn3, and the spa may shut down or ignore temperature settings.
|
Auxiliary / Ambient Temperature Sensor Failure | View Details |
| UV |
Display shows UV or UVC, and the UV sanitizer indicator is off or flashing.
|
UV Sanitizer Lamp or Ballast Fault | View Details |
| — — |
The display is blank or shows only dashes; the spa is not responding.
|
Topside Control Panel Communication Failure | View Details |
| – |
Air blower does not turn on or shuts off quickly after starting.
|
Air Blower Failure or Overheat Protection | View Details |
| – |
Jets are weak, or some seats have very little water pressure even though pumps run.
|
Hydraulic Flow Restriction / Air Control or Diverter Misconfiguration | View Details |
| – |
Loud grinding, squealing, or rattling noise from the pump area when jets are on.
|
Pump Motor or Wet End Mechanical Failure | View Details |
| – |
One or more jets have popped out or will not stay in place.
|
Jet Internal Retainer Wear or Damage | View Details |
| – |
Persistent foaming on the water surface even after rinsing filters.
|
Surfactant Build-Up / Water Contamination | View Details |
| – |
Pump runs, but no water comes out of the jets after draining and refilling the spa.
|
Air Lock in Pump or Plumbing | View Details |
| – |
Spa is leaking water inside the equipment bay or from under the cabinet.
|
Plumbing or Component Leak | View Details |
| – |
Spa lights flicker, some LEDs are out, or colors do not change correctly.
|
LED Lighting System Degradation or Driver Fault | View Details |
| – |
Spa trips the GFCI breaker immediately or within a few seconds of turning on.
|
Ground Fault or Short Circuit in Spa Components | View Details |
| – |
Spa water cools down quickly between uses even though the cover is on.
|
Heat Loss / Insulation or Cover Inefficiency | View Details |
| – |
Spa water has a strong chemical or musty odor despite normal readings.
|
Water Quality Imbalance / Biofilm or Contamination | View Details |
| – |
Spa will not heat; water stays cold, but pumps run normally, and no error code is displayed.
|
Heater Element Failure Without Code | View Details |
| – |
Spa will not turn on at all; no lights on the control panel, completely dead.
|
No Power to Spa / Control Pack Not Energized | View Details |
| – |
Topside control buttons are unresponsive or activate incorrect functions.
|
Keypad Overlay or Topside Control Failure | View Details |
| – |
Water feature (waterfall or fountain) is not flowing or is very weak.
|
Water Feature Flow Restriction or Valve Misadjustment | View Details |
| – |
Water seeping around one or more jets on the spa shell.
|
Jet Body Gasket or Locknut Leak | View Details |
| – |
Water temperature overshoots the setpoint by several degrees before the heater shuts off.
|
Temperature Regulation Inaccuracy | View Details |
No matching codes found
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