Weil-McLain 633-500-020 Kit-S Thermostat Repair Kit (63°C) - AquaPLUS Residential
A Weil-McLain thermostat repair kit for AquaPLUS residential indirect water heaters, used to restore temperature control when the existing thermostat has failed.
Key Features:
- Thermostat repair kit identified as Kit-S Thermostat repair kit, 63°C AquaPLUS Residential
- Part number/SKU: 633-500-020
- Manufacturer parts catalog description: Thermostat Repair Kit includes thermostat and instructions
Compatibility & Applications:
- Listed for use with AquaPLUS water heater models: 35, 45, 55, 85
- Must only be used where the manufacturer specifies this exact part number: 633-500-020
Installation & Operation Notes:
- Installation/service should be performed by a qualified heating installer/service technician, following the water heater's product manual and all information shipped with the unit
- Manufacturer manual safety guidance for servicing includes:
- Disconnect electrical supply before performing maintenance (to avoid electric shock)
- Allow the water heater to cool before performing maintenance (to avoid severe burns)
- Follow the unit's manual for the correct replacement procedure and to verify the correct part for the specific model
Maintenance & Troubleshooting:
- This kit is used when thermostat-related issues prevent normal hot water operation (review-reported examples include sudden loss of hot water and thermostat failure)
- If issues continue after replacement, the manufacturer documentation should be used to confirm correct installation and verify any related controls or wiring (the kit is only one part of the overall control system)
User Reviews & Q&A Summary:
- Reviews are mixed: many describe it as an exact-fit replacement that restored hot water quickly, while others report repeated thermostat failures over time and frustration with having to replace the part periodically .