Look for physical indicators such as a bulged top

The Johnson Controls T-4002-125 is a professional-grade plastic surface mounting back designed specifically for the T-4000 Series pneumatic thermostats

System 450

Identify your line voltage (120

this 2-way zone valve body features the industry-standard Erie PopTop design

Raypak 006021F Sensor Look for physical indicators suchThe Raypak 006021F Roll Out Flue Sensor is a safety critical 150F fixed temperature switch engineered for precise thermal monitoring in high efficiency Raypak boiler parts and pool heaters. As an essential OEM HVAC replacement sensor, this component is designed to detect flame roll out or excessive flue gas temperatures, immediately breaking the safety circuit to prevent damage to the heat exchanger or cabinet. This Raypak roll out switch functions as