PEX Pipes Plumbing Project

My big DIY project to replace galvanized pipes with PEX... as well as reorganizing plumbing into a manifold system, and installing a pressure regulator.

Final results

Pressure regulator and PEX manifold

PEX manifold

Why though?

When I moved into the house, I noticed that there is some particularly bad corrosion (and leaks) where someone decided to connect copper pipes directly to steel. Cool way to make a battery for 9th grade chemistry, not a cool way to do plumbing.

What is even more baffling is that the plumber said that "this is normal given the age of the house". That's one hell of an excuse for almost anything.

Most of the valves were leaky to begin with, leaked when closed, or were corroded open and impossible to turn at all. One of the loosely-attached copper pipes burst when I was trying to replace a sink valve.

The high pressure from the city water supply did not help any of this either.

Much later, I also saw corrosion and rust accumulated inside of these galvanized pipes.

So galvanized pipes had to go. I did not want the corrosion to develop into full leaks at the visible spots, nor for it slowy eat away at copper where I cannot see. And since I planned to bypass galvanized pipes and install a pressure regulator, I might as well centralize the controls onto a manifold instead of relying on pipe spaghetti and stuck valves throughtout the basement.

Progress

Most of this was built with PEX supplies from Lowe's hardware store and SharkBite push-to-fit connectors. Main cold water pipe and connections to the water heater are 3/4", the rest of the pipes are 1/2".

What I started with: cold water line coming in, a meter, and not much space to fit a pressure regulator. It's a galvanized pipe going up, and I can't easily cut and connect into that. So I need to find a way around to give myself more space.

While the main cold and hot trunk pipes are galvanized, most of the branching connections are, thankfully, copper. Since I want to bypass the galvanized pipes, I thought it would be a neat idea to centralize water control and build a manifold system.

Installed a thick plywood board to mount the manifold to.

Installed the manifold. They are pricy, $200+, but are very easy to work with.

3/4" valves on top go to and from the water heater, and a tee on the right is for cold water in.

Once I connect the cold water and the water heater to the manifold, I should be able to bypass the cold water connector after the meter.

Assembled pressure regulator, pressure meter, push-to-fit connector for a 3/4" pipe going up to the manifold, and a valve going down for a temporary bypass / drain, all connected with brass parts. The meter connector on the left is a special part that I had to order separately, as they are not normally sold in big-box stores.

Brass connectors were kind of frustrating. They appeared straightforward enough, but leaked a lot once connected, leading to several re-assemblies. The threads require a lot of plumber's tape, and I wish I knew to use the grey 3mil tape here instead of the regular white.

Pressure regulator installed, connected to the manifold above, and a bypass connected to the cold water pipe. This barely fits with the round water meter in place.

Now I can start running PEX from the manifold to the brach copper lines, which can be easily cut, connected, and capped.

Since I run pairs of 1/2" PEX in tight spaces, it is sometimes difficult to use clamps with nails (and I prefer not to hammer close to old rusty pipes), so I designed and 3D-printed a few dozen paired holders for mounting PEX pipes underneath and on the side of joists.

I don't know whether this is generally acceptable, but a lot of plumbing here (both galvanized and copper) is barely attached, and is often supported by itself. This is one example - the water intake system for the boiler was held by a galvanized pipe on top and a thin 1/2" copper pipe on the bottom, not attached to a wall or any other structure. So I had to put a 3/4" (purely for structural reasons) copper pipe in place of the existing galvanized pipe, and carefully attach the intake contraption to the new pipe. Another series of frustrations with brass fittings here, too.

The only galvanized pipe that I could not easily replace is the one going to the toilet in the half-bath on the first floor, because it is cemented in tile and is difficult to reach behind a joist at the edge of the basement. But thanks to the advice of a nice lady in Lowe's, I used this press-fit coupling (called "galvanized pipe repair kit", I believe) to connect the cut galvanized pipe to a short threaded piece with a push-to-fit connector.

While I was at it, I replaced the old leaky washer connectors with new quarter-turn ones.

And replaced a bunch of moldy drywall.

[ANXIETY INTENSIFIES]

Middle of the process.

All that was left was to cut some galvanized pipes that were in the way and unsupported.