Hi Mandy,
All I can find is a Henfache Farm in Llanrhaeadr Ym Mochnant in the old days in Denbighshire (now Oswestry, Salop)
I have also traced a Henfache township once again in the Parish of Llanrhaeadr Ym Mochnant in the pre 1974 county of Denbighshire.
This was correctly called Henfachau which is a 'proper' Welsh spelling meaning 'old corners or bends or nooks'.
Hope this helps, cheers Dave