Jack's place is in a phenomenal location literally just 2 mins away from Harrods. In addition it is spacious yet cosy with two full size bedrooms and two full size bathrooms. The living room is well furnished and spacious.
We had a great time seeing London from Jacks flat, and when we had exhausted ourselves sightseeing it was nice to have such a nice place to come back to!
Only thing I would caution is that this is on the 2nd floor and so there are 3 small flights of stairs (we had no issue with this but It does rule it out for people with knee issues) to get to the apartment.
No issues with heating plumbing or anything else in the flat.
The street and apartment block is fantastic, very costly and well maintained. Jack is responsive and his instructions clear.
Highly recommended