Re: Hotpoint FDL 570 fault codes / flashing lights.
Both the heater and the circuit board are known weak points on Indesit appliances. The NTC is hard wired to the pcb which needs programming. The heater is part of the main pump assembly and is not a quick, simple fix.
The heater would need testing for continuity/resistance before you even think of buying any parts.
The heater is around £50, the main pcb is £70.00 but needs an £18 smart card and a £100+ card reader to programme it.