and CTR-921

Using a switch with a different water column rating can lead to unsafe operation or frequent nuisance trips

Built to withstand secondary water hammer

Whether you are troubleshooting a 3-flash error code or performing a full system overhaul

Once the system cools to 135°F

Carrier EF33CZ256 Gas Valve 320074-702 and CTR-921The Carrier EF33CZ256 Gas Valve is a reliable 2 stage gas control designed specifically for liquid propane (LP) applications in high efficiency heating systems. Operating on a standard 24V furnace control circuit, this valve features a low fire setting of 4. 8" WC and a high fire manifold pressure of 10. 5" WC, ensuring precise fuel to air ratios for optimal combustion. As a direct replacement for the EF33CZ256A, this OEM component is commonly found