meaning you can mount the control box in an accessible area while the sensing bulb is placed directly in the air stream or on the coil surface where temperature monitoring is critical

this model is part of the VT series designed for hot and chilled water

and UDAP series

it functions independently of external power

Lochinvar & A.O. Smith 100109294 Pilot Assembly 318518-761 meaning you can mount theThe Lochinvar & A. O. Smith 100109294 Pilot Assembly is a precise OEM replacement engineered for Flammable Vapor (FV) ignition systems. Designed for use in Propane (LP) residential water heaters, this 160 Degree Celsius rated assembly ensures critical thermal safety by maintaining the correct ignition sequence and flame rectification. As a high performance FV Pilot Assembly, it integrates a durable thermopile or thermocouple (depending on specific