A boiler service and maintenance valve (20) comprises a body (21) having a first connector (28), a second connector (29), and a separate flush entrance (31). Each of the first connector (28) and the second connector (29) is adapted for connection to a conduit of a water heating system (60). The body (21) further comprises a valve member (47) arranged for movement between at least a first open position for opening the flush entrance (31) and a closed position for closing the flush entrance (31). The first open position allows fluid communication between the flush entrance (31) and at least one of the first connector (28) and the second connector (29). The closed position allows fluid communication between the first connector (29) and the second connector (29), but not the flush entrance (31).