I think it would be overflowing and flooding the place, there is so much wrong there. :eek:
I did the unvented course in the early 90s, at the time I was told the qualification would last for ever. Not sure when the rules got changed but I would have to go on another course and pay hundreds...
You need someone that is qualified to work on unvented hot water storage systems
I no longer have this qualification, but I have a similar system and installed this type before.
Unfortunately whoever fitted this system, (from the photos I can see) is probably also not qualified IMO.
Look for...