Error E06
Pentair Pool Heater
Severity:What Does This Error Mean?
Pentair MasterTemp Error E06 indicates the stack flue sensor detected an overtemperature condition — the exhaust temperature exceeded safe limits. The most common cause is blocked airflow through the heater. Clear at least 2 feet of clearance around the heater and ensure the exhaust vent is unobstructed.
Affected Models
- Pentair MasterTemp 125
- Pentair MasterTemp 200
- Pentair MasterTemp 300
- Pentair MasterTemp 400
- Pentair MasterTemp 250
Common Causes
- Blocked air intake or exhaust vent
- Heater installed too close to a wall or fence
- Stack flue sensor dirty or failing
- High-limit switch tripped from sustained overheating
- Combustion air quality issue (too much CO2 in recirculated air)
How to Fix It
-
Turn the heater off and allow it to cool for 20 minutes.
E06 is a safety shutdown — the heater will not restart while the stack is overtemperature. Do not attempt to force a restart while the unit is hot.
-
Check all four sides of the heater for clearance.
The Pentair MasterTemp requires 2 feet of clearance on all sides and above. Remove any objects, plants, or structures within this clearance zone.
-
Inspect the exhaust vent for obstruction.
A bird's nest, leaves, or other debris blocking the exhaust can cause combustion gases to recirculate inside the heater, raising exhaust temperatures. Check and clear the vent opening.
-
Check that the air intake screen is clean.
The air intake screen on the sides of the heater can collect debris and restrict combustion air. Remove the screen and clear any lint, leaves, or insect nests.
-
Contact a technician if E06 persists after clearing clearance and vents.
A persistent E06 with good ventilation suggests the stack flue sensor or high-limit switch has failed. These components require a licensed technician to test and replace.
When to Call a Professional
E06 from a failed stack flue sensor or a tripped high-limit switch that does not reset requires a licensed pool heater technician to diagnose and replace the component.
Frequently Asked Questions
What does E06 mean on a Pentair MasterTemp heater?
E06 means the stack flue temperature sensor detected exhaust gas exceeding the safe limit. The heater shuts off as a safety measure. The most common cause is blocked airflow — clear the clearance zone around the heater.
Can E06 damage a Pentair MasterTemp heater?
Occasional E06 events from temporary obstructions do not damage the heater. Frequent E06 trips caused by a blocked site location or faulty sensor can stress the heat exchanger over time. Relocate or service the heater if E06 is occurring regularly.