How to Reset a Pentair Pool Heater and Clear Error Codes

Quick Answer

Pentair MasterTemp heaters support three types of resets. A soft reset clears active fault lockouts by pressing ON/OFF, waiting 30 seconds, then pressing ON. A hard reset involves shutting off the gas valve and cutting breaker power for 60 seconds. The SERVICE HEATER interval counter is cleared separately by holding Menu for 5 seconds and navigating to the Service Reset option.

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Not seeing RESET on your display?

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fault lockout requiring reset

HaywardRESET

How to Reset Your Pentair Poolheater

Three Pentair reset methods: soft reset (ON/OFF button), hard reset (gas off + breaker off 60 sec), and service interval reset through the Menu.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Fault lockout requiring manual reset to resume operation40%

Transient fault (power blip, brief low flow) that has self-resolved24%

Post-repair reset after replacing parts22%

SERVICE HEATER maintenance interval counter reached14%

Symptoms You May Notice

Heater locked out and displaying error code
SERVICE HEATER indicator on after annual maintenance
Heater unresponsive after power interruption
Error code cleared but heater not resuming automatically

Tools Required for Diagnosis

None required for basic reset

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Note and record the exact error code showing on the display

Note and record the exact error code showing on the display before resetting. A reset clears active faults but does not fix the cause - if the code returns, you need the specific repair guide.

Soft reset

Hard reset

To clear the SERVICE HEATER maintenance counter: press and hold

Run the heater through a complete heat cycle after any reset and

Frequently Asked Questions

How do I reset a Pentair MasterTemp pool heater?

For a soft reset, press the ON/OFF button, wait 30 seconds, then press ON. For a hard reset, close the gas shutoff valve and cut the 240V breaker for 60 seconds before restoring both. This clears most fault lockouts.

Will resetting my Pentair heater fix the error code?

A reset clears the lockout so the heater can attempt another heat cycle, but if the underlying cause is not fixed, the same code will return. Think of a reset as a diagnostic tool - if the code returns within one cycle, the fault is still active.

How do I clear the SERVICE HEATER light on a Pentair MasterTemp?

Hold the Menu button for 5 seconds while in standby to access the service menu. Navigate to Service Reset and confirm. This resets the maintenance interval counter. If the light returns immediately, check the diagnostic history for an active fault code.

Is there a reset button on a Pentair pool heater?

There is no dedicated physical reset button. The ON/OFF button on the control panel serves as the reset trigger when held or pressed in standby. Some internal safety devices like the high-limit thermal fuse do not reset and must be replaced if they trip.

How many times can I reset a Pentair pool heater before it needs repair?

There is no hard limit on resets, but repeating the same reset for the same recurring code is not a fix - it is a sign the root cause needs repair. Repeatedly forcing ignition retries, for example, can damage the igniter and gas valve over time.

Related Pentair Poolheater Error Codes

Code: HUBPentair Pool Heater Error Codes Guide Code: E05Pentair Pool Heater E05 Error Code Code: ERR IGNPentair Pool Heater ERR IGN Error

Same Fix on Other Brands

Hayward poolheaterHow to Reset a Hayward Pool Heater

Models Known to Experience RESET Errors

This repair applies to most Pentair poolheaters with this error code. Common model numbers include:

MasterTemp 400, MasterTemp 250, MasterTemp 300, MasterTemp 125

Last verified for technical accuracy on March 14, 2026