Sensus 138-18-021-01 Spring provided the furnace itself is

provided the furnace itself is properly derated for high-altitude use

this plate is used in conjunction with the screws provided with your thermostat sub-base or standard 6-32 junction box screws

when used within a properly configured Sensus 143 regulator

the Nortek 151888R acts as a calibrated restrictor that regulates the volume and velocity of airflow through the draft inducer

How do I test my furnace rollout switch for continuity

Sensus 138-18-021-01 Spring provided the furnace itself isWhen you're servicing or upgrading a Sensus 243 RPC regulator, precision in your spring selection is what prevents callback heavy issues like pressure drift or poor lock off performance. The Sensus 138 18 021 01 White Spring is the industry standard for technicians needing a reliable 1 to 5 PSI outlet pressure range. This heavy duty RPC pilot spring is specifically engineered to handle the unique relay action requirements of the Sensus Gas Division