Found In These Collections
OEM Hayward HDXFHLI400 High Limits, replacing former model HDXFHLI001, are critical thermal safety devices for Universal HC Series HDF400 pool heaters. These switches play an essential role in regulating the heater's safety by detecting excessive water temperature and instantly shutting off the unit to avoid potential damage. Manufactured with precision and durability in mind, they help protect key components from heat-related stress while supporting consistent heater operation. As a required safety feature, these OEM high limits are fundamental to the long-term efficiency and safe use of your pool heating system.
Highlights
-
Specifically Designed for HC HDF400 Heaters: OEM replacement switches ensure accurate temperature monitoring and thermal control
-
Automatic Protection Mechanism: Detects unsafe water temperatures and shuts down heater to avoid overheating and equipment failure
-
Prevents Costly Heater Damage: Acts as a thermal safeguard to protect sensitive internal parts from high-heat exposure
-
Engineered for Reliability: Built using heat-resistant materials and calibrated for consistent, accurate high-limit response
-
Ensures Safe Pool Heating Operation: Helps maintain safe operation by enforcing temperature thresholds throughout heater cycles
Compatibility
- Compatible with Universal HC Series HDF400 Heaters
Error Codes
Potential error codes that may require you to replace your High Limits are:
HS - High temperature sensing error
-
A) Inlet water temperature sensor is reporting a temperature in excess of 104°F. Normal operation resumes 2 minutes after inlet water temperature sensor reports temperatures of 104°F or less. This error functions for both normal and remote thermostat modes. or
-
B) Inlet water temperature sensor is reporting a temperature change at a rate faster than 6°F in 60 seconds or less while the heater is firing, indicating a potentially damaging low water flow condition. Normal operation resumes when temperatures stabilize. If this condition is detected 3 times in a one hour period, the heater will lockout.
Additional Info
Diagnosing Overheating Issues
heater keeps reaching max temp high limit tripping
troubleshoot heater lockout on hc-series hdf400
error code on screen related to temperature sensor
how to fix hdf400 heater that shuts off too soon
heater runs hot then stops hdxfhli400 needed
Component Specs and Local Pricing
check local price on hayward high limit switch kit
difference between hdxfhli001 and hdxfhli400
heat sensor part for hdf400 high temp shutoff
buying heater high limit locally for fast repair
high temp cut-off sensor replacement for hayward
Compatibility Confirmation
is hdxfhli400 compatible with all hdf400 units
which hc-series models use this safety switch
part number for high limit switch hayward hdf400
local store with hayward heater temp safety switch
confirm fitment of hdxfhli001 before local purchase
Diagram
