Resideo 191990A Replacement Keys

The Resideo 191990A Replacement Keys are essential service components designed for field technicians and facility managers maintaining Honeywell Home Versaguard thermostat guards. This set includes two precision-cut keys specifically engineered to fit TG509, TG510, TG511, and TG512 series lockable covers. This specific part number, 191990A, is technically identical to the 191990A/U model, ensuring a seamless thermostat guard key replacement for both residential and commercial enclosures. Constructed from durable metal, these keys facilitate secure access to terminal connections and setpoint adjustments while preventing unauthorized system tampering. For HVAC personnel, keeping these on the truck ensures immediate access to legacy and current Versaguard enclosures without the need for destructive entry. These thermostat lock box keys are a direct match for the original equipment manufacturers' specifications, maintaining the integrity of the Resideo thermostat guard security assembly.

• Compatible with any TG509 through TG512 series thermostat guard for universal fleet application.
• Cross-compatible with 191990A/U indices, ensuring consistency across different stock versions.
• Provides a set of two keys to maintain a secondary backup in a technician's kit or on-site locker.
• Fabricated for high-cycle use within Versaguard locking mechanisms to prevent snapping or binding.

• Are these keys universal for all thermostat guards? No, these are specifically for Resideo and Honeywell TG series guards; they are not intended for third-party universal plastic boxes.
• What is the difference between 191990A and 191990A/U? There is no technical difference in fitment or function; the "U" designation typically refers to retail or universal packaging.
• Can these be used to lock or unlock the guard while the key is in any position? Standard operation requires the key to be in the locked position for removal to ensure the enclosure remains secure.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.