Mira shower red light flashing

Personally I’d replace it sooner rather then later and have an electrician check your wiring at the switch I had the same problem with my own last year and to start with it lit up red ,then it shut off and I had to turn the shower off at the wall for 10-20 mins to let it cool down before it would come on again , then one day I was coming out the shower and I smelt burning I followed the smell to my shower switch and when I tried to shut it off it was stuck so I turned it off and the mains and when I opened the switch I found the innards had melted and the wires were also melted and burnt , so I replaced the switch (after stripping the wires back to clean luckily I had enough length ) and about a week later the shower packed in completely so I replaced that as well but If I hadn’t of smelt it that day a fire could have been caused from that socket and despite the state of the wires and switch my rcd hadnt tripped so I’d say better safe then scorched .Hope this helps