Fuel Fired Booster Heater (FFBH) Coolant Pump
WARNING: This page is about a different car, the 2018 Jaguar XE and 2017 Jaguar XE. However, it is still accessible from the selected car via links, so may be relevant.
The Fuel Fired Booster Heater (FFBH) coolant pump is an electric pump, the pump's intake is connected to either the heater coolant feed from the engine (on vehicles without timed climate control) or to the FFBH changeover valve (on vehicles with timed climate control). A hose, which incorporates a bleed screw, connects the outlet of the coolant pump to the coolant inlet of the FFBH.
The coolant pump runs continuously while the FFBH is in control idle or active operating modes. While the FFBH is inactive, coolant flow is reliant on the engine coolant pump.