Ideal Boiler Efficiency meter

Hello

Had an unvented heating system installed last week. It came with an Ideal Vogue S32 Gen 2 boiler. Since the install the efficiency meter has been around 10-13% when it should be around 80%. My engineer phoned Ideal and noticed that the flow temperature was only set at 1 degree!

This was changed to 70 degrees so the return was around 50. We assumed this would fix it but it is not going up. In fact one day ot can be 13% then the next day back to 10%

I called Ideal and they said it could take 6 months for the reading to change. This is due to some boilers being wet tested in the factory and some being dry tested. They still could not explain why some people have a 80% efficiency level straight out of the box. They even told me it should not go down, which mine is doing. I asked them if the boiler is faulty and there reply is the boiler will not be faulty.

I am convinced there is something wrong with my boiler and I am now waiting for another call back from Ideal.

Can any installers advice me what they think?

Thanks