The kettle is on and starts to warm up but then dies down but the switch stays on. It then builds up again and dies down constantly and never gets to boil
As below, a poor connection on the plug lead could very well be the issue in addition to a failing heater element. Taking into account the potential safety issues of a faulty appliance, a Morphy Richards kettle is simply not worth wasting the time or effort trying to perform a repair. They are so cheap that I'd advise chucking it in the bin and buying a £15 new one from Argos in the morning.
Rupert
May 2020
Check the plug, lead and socket are not getting hot. Replace if necessary