I currently have a Mira Jump (7kW?) electric shower in my en-suite which only outputs cold water so suspect the heating element is damaged.

You will need to ensure all the fittings are installed properly as the last person didn't install the post to hold the shower head correctly. Please also ensure the electrics are safe.

I have ordered Mira Sport 9.8kW electric shower to be delivered Friday 21/09 so I'm looking to get this fitted Saturday 22/09 or Friday depending on what time the shower arrives.