Heater Not Firing / No Ignition
Pentair Pool Heater
Severity: CriticalWhat Does This Error Mean?
A pool heater that will not fire could have a gas supply issue, a tripped safety switch, or a failed igniter. Check gas supply, flow, and look for error codes on the heater's display.
Affected Models
- Pentair MasterTemp 200
- Pentair MasterTemp 300
- Pentair MasterTemp 400
- Pentair Max-E-Therm
Common Causes
- Gas supply turned off or low gas pressure
- No water flow — flow switch not detecting water
- Igniter failed — no spark to light the burner
- High limit switch tripped from overheating
- Exhaust vent blocked
- Pressure switch not closing
How to Fix It
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Check that the gas supply valve is open.
Follow the gas line to the heater. The valve handle should be parallel to the pipe (open). Perpendicular = closed.
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Make sure the pump is running and flow is adequate.
The heater will not fire without water flow. Check for a No Flow error on the display.
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Check for error codes on the heater display.
Pentair heaters show specific fault codes: E01 = ignition failure. E02 = flame lost. E04 = flow switch. The code tells you exactly what is wrong.
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Reset the heater: turn off, wait 30 seconds, turn back on.
A tripped safety switch sometimes clears with a power cycle.
Frequently Asked Questions
Why does my heater click but not light?
Clicking means the igniter is sparking but gas is not reaching the burner. Check the gas valve, gas pressure, and whether the pressure switch is closing.
How long should a pool heater last?
Gas pool heaters typically last 7-12 years with proper maintenance. Annual service extends the lifespan significantly.