It’s a one shot. There’s a modified heater box kit available too if you can give us the date code? I’ve replaced the one shot with a Qualtex TOC27 to those machines that are subjected to customer mis-use (in flats and lettings with multi-users 😉 )
TOC for that is a 1605160. It appears as though the modified heater box has been modified yet again. It now incorporates the flushing valve and fluff filter, and the spiral element again, also a thermal cut out simliar to the old style microtemps used on the earlier Hotpoint washer/dryers, this change took place after date code 60, May 2006.