The Bosch Protankless FX Hood, part number FXHOOD, is a 4-inch diameter galvanized metal termination hood designed for sidewall exhaust venting on compatible Bosch Protankless and AquaStar FX series power vent tankless gas water heaters. The FXHOOD mounts at the exterior wall penetration point and serves as the terminal exhaust outlet through which combustion gases are discharged to the outside. An internal flapper mechanism closes the hood opening when the heater is not in operation, blocking cold outside air from entering the vent pipe and reaching the heater.
The internal flapper is a passive backflow prevention component that responds to the pressure differential created by the heater's power vent fan during operation. When the unit fires and the blower engages, the flapper opens to allow exhaust gases to discharge freely through the hood. When the heater shuts down and the blower stops, the flapper returns to the closed position under its own weight, sealing the vent termination against cold air infiltration and wind-driven backdraft. The galvanized metal construction provides weather resistance suited to exterior sidewall installation in residential applications.
What's Included: One Bosch FXHOOD 4-inch diameter galvanized metal sidewall termination hood with internal flapper backflow prevention mechanism.
Installation Limits: The FXHOOD is designed exclusively for sidewall horizontal venting termination on compatible Bosch FX series power vent tankless gas water heaters. It is a 4-inch diameter fitting and must be matched to 4-inch vent pipe. It is not designed for vertical or through-the-roof venting termination applications.
Compatibility: Compatible with Bosch AquaStar 125FX and Bosch AquaStar 240FX power vent tankless gas water heaters requiring a 4-inch sidewall exhaust termination hood.
