What on Earth were they thinking?

When we bought the house, we realised, after a few weeks that we had a leak. Try as hard as we could, we could not find it. We could hear water running along pipes, but no sign of any water collecting on the floor. As part of the inevitable process of updating, reconfiguring and generally shifting bits of the house around, I removed a built-in cupboard in the entrance, near the house fuse box and behind some nice sliding doors. Imagine my surprise to discover that instead of the one water heater at the far end of the house, we had a second one, there, in the lobby. The sides of the fitted cupboard were fitted flush to the stud wall you can see in the picture, boxing it in completely. The leak was coming from the bottom of the boiler at the overflow valve, which had calcified open. A steady stream of drips were exiting and going down the overflow pipe to the septic tank. Hence, no visible signs of the issue. Valve replaced, leak sorted. However, a job has hung over me for ages. Remove the stud wall so that we can actually access the boiler easily and use the space more efficiently. Today was the day. Wall smashed and cleared. Additional pics to show work. Now, just have to skim and fill holes, paint walls, tile and grout floor, refit cupboards and shelves and allow dog back in to his room. That starts tomorrow.