A.o. Smith 100108421 Lower Thermostat Electric WH9

Product Description

The A.O. SMITH 100108421 is a lower thermostat designed for electric water heaters operating at 240 volts. It controls the lower heating element in a two-element electric water heater tank, cycling the element on and off to maintain the set water temperature in the lower portion of the tank. This thermostat is a direct replacement component intended for installation by licensed plumbers or water heater service technicians working on residential electric storage water heaters.

This thermostat is rated for heating applications at 240 volts and is specifically matched to the A.O. SMITH WH9 model series. It is not rated for point-of-use water heaters. Typical installations are in standard tanked electric water heaters found in residential settings where the lower thermostat has failed or requires replacement as part of routine maintenance.

Key Features

• Rated for 240-volt electric water heater systems
• Controls lower heating element temperature in dual-element tank water heaters
• OEM-matched replacement for the WH9 model series
• Not suitable for point-of-use water heater models

Compatibility

Designed as an OEM-style replacement lower thermostat for the A.O. SMITH WH9 electric water heater model series. Do not install on point-of-use model water heaters.

Installation Notes

Installation should be performed by a licensed plumber or qualified water heater service technician. Always shut off electrical power to the water heater at the breaker panel and verify power is off before removing the access panel or handling any electrical components. Drain pressure from the system as appropriate before servicing internal components. Refer to local plumbing and electrical codes for applicable requirements.

Technical Specifications

• Voltage: 240 volts
• Application: Heating
• Compatible Model: WH9

Standard Information

• Brand: A.O. SMITH
• Manufacturer Part Number: 100108421