The Peerless® Pinnacle® PI-399 gas-fired, commercial boiler from Peerless Boilers is available for either natural or LP gas. The direct-vent, sealed combustion boiler offers a fully modulating burner and 95% combustion efficiency. Spark ignition, a safety relief valve, and the Krom Schroder Gas Valve-Venturi System all are standard features and ensure safe, efficient operation. The Peerless Pinnacle PI-399 boiler is equipped with a revolutionary P125 Control Board. Supply and return temperatures, flame signal, fan speed (firing rate) and more can be viewed from an LED digital display module for enhanced boiler serviceability. A switch to "service mode" enables manual control of the firing rate. Peerless Boilers.