Bunch of weird stuff going on. This all started when I gutted an old basement apartment out of my house. There was a bath down there and I just cut the lines to it and capped then off. When I did that I started getting leaky faucets, shower heads, the HW heater pressure relief valve blew, etc. I put a psi gauge on my utility sink in the basement and it sat most of the time at 60 psi but it would spike sometimes to 120psi! There was a leak in the old bath that I removed so I suspect the leak was providing a relief for the pressure. When I capped the lines I sealed the system and exposed the problem. The hot water is also acting weird now. For example on my shower mixer we'll say 6 o'clock is off, 9 if full hot. I usually set it to about noon when I shower. Now I turn it on it is almost too hot at about 2 for a couple minutes then cools down and I have to move it to about 10 and the HW doesn't last long. Here is what I did this weekend. My feed from the street comes in the front of my house and all the plumbing is in the back and I only had 1/2" running across the basement so I wanted to upgrade to 3/4" anyways so I saw this as an opportunity. I ran new 3/4" PEX across the ceiling from the front to the back. Coming off the meter I put on a new pressure regulator, hooked it to the new PEX. At the other end I have basically a manifold, all 1/2". I cut the old 1/2" feed to that and reduced the 3/4" at this point to 1/2" to feed it. (I plan on upgrading all the lines eventually) I also added an expansion tank on the supply side feed into the HW heater. I also put a new pressure relief valve on the HW heater. Turned the water back on, everything looked good and was reading 60psi. I checked it last night and at some point it had spiked to 100psi. My shower mixer was still jacked up too. It seems all my changes did nothing to solve my problems. Not sure what the next move would be. The HW heater is like 18 years old. Is it possible that could cause these problems? Also, when connecting the new pressure reg and PEX I realized my line from the street and the meter is only 1/2". After the meter I go to 3/4" across my ceiling then back down to 1/2". about a 50ft run. Is that all a waste of time since I have only 1/2" from the street? Will it cause any problems? Sorry for the long post but I had to explain it all.

Hi. We have a renovated home in which the plumbing was entirely redone with CPVC. Lately I have noticed an occasional loud "pop" when our washing machine or dish washer runs. We've been here for a few years and this seems to have just started. While I havent gone into the crawl space to look where it is exactly, I believe it is the main supply line based upon where the sound is coming from. This is also the longest, straightest pipe in the crawl space. In the mornings, we also have banging problems occasionally when the water is first turned on. But because the banging decreases in volume while increasing slightly in frequency until it stops, I assume this is just banging against the joists or studs. From having been in the crawl space, I know the plumber was skimpy with pipe hangers. I have a few questions: 1. Is water hammer supposed to be an issue with CPVC piping? All the water hammer arrestors I see online appear to be for connecting to copper piping. 2. Why would this suddenly just become a problem? 3. How would I go about fixing this? I saw on Amazon people with LG front loaders (like we have) having success with water hammer arrestors connected directly to the supply hoses. Assuming this would work for us too, this would only fix the washing machine but not the dishwasher. If it matters, the supply line I described above enters into the laundry room, where the PRV and water heater are located. The PRV is accessible in this room, and since we live in a single story home, its location is actually the highest point of plumbing except for possibly the shower heads.