My JRT has decided that he likes peeing indoors now. Its driving me nuts. Its mostly my dining table legs, corners that jut out from the wall etc.

I'm looking for recommendations for a proper enzyme cleaner for hard surfaces?

And any other ideas much appreciated before I lose my mind

Simple Solution is good, they have a type for hard surfaces.

I assume this is a dog that has been reliably house trained already?

If so then this is likely to primarily be a behavioral/training issue.

So working outbwhy, and then looking at long term solutions.

A friend had this issue with her Doberman male when he reached puberty.

After he peed into a socket and blew the electrics she had to do something.

The something she didvwas supervision, containment, and disaproval/redirection of attempts to 'mark' indoors.

She kept at it solidly for about 6 weeks. He was crated all the time he was not strictly wstched or in garden.

I assume it's marking due to locations.

If it's full bladder emptying, then a check on if there is a health issue, infection?

First thing I would do is get a urine sample tested

I have always used this 'Animal Care Odour Eliminator'. Excellent stuff. Google it, available many places and ebay.

http://www.animalcare.co.uk/pet-hygiene#:~:text=Odour%20Eliminator%20is%20concentrated%20and,with%20a%20cloth%20or%20spray.&text=A%20ready%2Dto%2Duse%20enzyme,up%20the%20natural%20degradation%20process.

https://www.ebay.co.uk/itm/203078587843

What is he like in general?  Confident or cautious?  Happy on walks?  Often peeing indoors can be an insecurity thing, more in small dogs.

How old is he?

If it’s a new behaviour I would definitely get a wee sample checked before assuming that it’s behavioural.