While the 4075-029 is typically serviced as a complete assembly to ensure seal integrity

The Watts 0121542 is a high-capacity boiler pressure relief valve designed for commercial and industrial hydronic heating systems

such as fan coils

While it provides 60 VA of power

The 3H1B1 is compatible with all Warrick Series 16

Carrier HK06NB010 Pressure Switch 322838-754 While the 4075-029 is typicallyThe Carrier HK06NB010 Pressure Switch is a factory authorized OEM safety component designed specifically for secondary heat exchanger monitoring and draft inducer verification in high efficiency gas furnaces. Rated at a fixed 1. 18" WC trip point, this SPST (Single Pole Single Throw) switch ensures the combustion blower is moving sufficient air to safely vent flue gases before the ignition sequence initiates. Constructed with a 1 4" barb connection