Hello. I have a dilemma. I have the front room of my house currently lifted for floor works and have noticed that the mains water pipe comes in from the front of the house (from the boundary water cock) on about 3m of 15mm copper pipe.

There is then a joint in this front room that connects it to a 22mm galvanised steel pipe.

The steel pipe then runs under a supporting wall through the rest of the house to the kitchen, where the internal stopcock is.

Water pressure is really, really good both downstairs and upstairs and after leaving the house for days or even weeks the water always flows clear, so no signs of rust or blockages.

Since the house is 1930's built, though i have no idea when the pipes were installed (noting there's already this copper pipe change in place). Is it worth changing this steel pipe now?

Also is the 15mm incoming pipe okay or should I increase to 22mm? House is on a combi boiler.

The dilemma is that it would mean tearing up the rest of the floors in the other rooms and kitchen and I'm really not sure if i have the appetite to do that if the steel pipe still has many years left in it. Esp. the kitchen with the units and appliances and everything. I guess I'm asking what the likely risk is and is it really a problem (leaks, blockages, health etc). I'm just glad its not lead!

Edit: I've managed to find the other end/ bend point of the pipe without too much damage so ill attempt a swap out for copper by feeding a straight run through. Luckily the bend also converts to another copper pipe! Thanks for everyone's input

I'm sure you sorted this out by now, but I'm posting for future reference.

Basically the service life of galvanized pipe is 60-80 years. It's not that it fails all at once, but the thin parts of the pipe and the areas exposed to other metals and slight electrical current are the first points to fail.

At the end of the service life, you'll run into new pinhole leaks, usually at joints, and internal corrosion/build-up.

If it's easily accessible and the pipe is from the 1930's, I would replace it. In my area, copper pipes are retrofit from the original lead, so this would tell me that the work is newer. If I thought the pipe is only 30-40 years old, I'd leave it in place.