F01 error code on most Hotpoint washing machines means “motor triac short”. The advice in the technical manual is to, “check motor and module connections”. This is not the type of error code that is helpful to most people. If you have this error you should book an appliance engineer to look at it.
The triac is an electronic component in the control module (PCB) or other printed circuit board. The suggested action of also checking connections shows that it isn’t necessarily a triac short. Clearly there’s an issue with it, but it could have shorted out or have a connection fault somewhere.
This error is likely to need an appliance engineer and maybe a replacement pcb. A a determined DIYer may decide to check all connections as suggested. Check the motor for continuity and carefully check the connections on the motor connector and where those wires connect to the main PCB. Electrical components shorting out (if that is what’s happened) could have external causes such as low insulation on another component, which also needs diagnosing.
A company called QER may be able to repair the pcb or at least test it if you are prepared to have a go at fixing it yourself. They used to have their own website but the last I heard they have moved on to eBay.
Note that in the comments below, someone has posted that they tracked down their F01 error code to poor connections in the motor plug, so it’s always worth checking connections first.