Smart Water Heater with LED Control - Electric Hot Water Tank and Shower Set - Storage Tank Boiler for Bathroom Heating

This water heater is not branded and there is no company address or website so nothing to confirm it complies with UK safety requirements and nothing to fall back on if you have a query or if something were to go wrong.It can be used as an unvented tank (straight from the water mains) but there is nothing to say whether it is safe to do so and no mention of an expansion vessel which is normally required for unvented systems.The 'instructions' are in very bad English so it's impossible to know if it's safe to be installed at mains pressure. There is a 'safety valve' underneath but who knows what that is or how it works.Unless you are a plumbing/electrical expert and are absolutely sure that this is safe to be used, don't use it.I tried asking questions about whether it was safe to use with mains pressure but got a non-comital answer and the question now seems to have disappeared from Amazon.On top of that, a shower with it only ran for 5 mins before going cold so useless for the purpose it was intended in any case!It was bought and installed in a rental flat by a 'plumber' but I'm now having to replace it with something I know is safe to make sure I comply with safety rules and also can be used for a hot shower of more than 5 minutes.