Optimized for infinite flame modulation

Professional Durability: Bimetal sensor housing is built to withstand the rigorous cycling common in heavy-duty commercial and residential HVAC applications

This specific model is calibrated for R-22

The nominal resistance is 1

Weil McLain 510-811-655 Valve Kit R-410A Optimized for infinite flame modulationThe Weil McLain 510 811 655 Valve Kit is a field proven combination gas control valve engineered for step opening ignition sequences in high efficiency hydronic systems. This 1 2" x 1 2" NPT natural gas valve provides precise pressure regulation, operating from a 0. 9" W. C. low fire setting up to a 3. 5" W. C. high fire output. Designed for compatibility with various Weil McLain boiler parts, this replacement gas valve ensures stable manifold