PENTAIR MASTERTEMP 400 Service Heater Light
| CONF | DIAGNOSIS | PART MATCH | ACTION |
|---|---|---|---|
|
86%
CONF
|
Stack Flue Sensor (SFS)
This sensor monitors exhaust gas temperatures to prevent the melting of internal plastic components. It is the most common point of failure in the MasterTemp series because its thermistor element is exposed to corrosive flue gases, leading to oxidation and incorrect resistance readings that trigger a safety lockout.
SKU: 42002-0024S
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CHECK PRICE |
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8%
CONF
|
Hot Surface Igniter
The igniter uses silicon nitride to reach temperatures exceeding 2500°F. Over hundreds of thermal cycles, the material develops micro-cracks that increase electrical resistance, preventing the part from glowing hot enough to ignite the gas-air mixture, which the control board detects as a failed ignition event.
SKU: 77707-0054
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CHECK PRICE |
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6%
CONF
|
Thermal Regulator
This mechanical wax-motor valve regulates the flow of water through the heat exchanger to maintain internal temperatures above the dew point. If the wax pellet leaks or the spring becomes encrusted with calcium, the valve fails to open, causing the heater to hit its internal high-limit safety setpoint.
SKU: 77707-0010
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CHECK PRICE |
DIY Repair Guide
Watch exactly how to replace the Stack Flue Sensor (SFS).