WWYD: Water Pressure - Shower issue or whole house?

Earlier this week I got in the shower to find that the cold water pressure was really high, and it was affecting the ratio of hot:cold. My wife had been in the shower 30 minutes before and said it was perfectly normal. I'm thinking something broke suddenly inside the shower spigot. However...

Yesterday our plumber took a look and said the issue is the water pressure coming into our house - it is too high. I didn't see him disassemble our shower fixture but I did watch him measure pressure at the utility sink in our basement. He said it was 100 pounds (psi?) and should be closer to 70. He said maybe it changed from the street/water company - water company says no. 

His assessment was we need a pressure control valve where the water comes into the house, and that we need some kind of rubber bladder attached to our water heater. Considering that I thought what we needed was a part inside a shower fixture that would cost maybe a few hundred, I was sticker shocked by the thousand dollar range estimate we got. The joys of home ownership.

He warned that excessively high water pressure will cause plumbing to fail, especially any plastic or rubber parts often used in connecting sinks, toilets, etc. Also that perhaps neighbors wouldn't notice a change in pressure from the water co. if they already have this pressure valve installed. I'm wondering if what has happened is that we do have high water pressure, it did cause our shower to fail and that installing this valve still won't actually fix our shower.

We're lining up an appointment to get a second opinion - but I thought I would also toss this out into MOL and see if anybody has experienced issues with high water pressure affecting their plumbing and if anybody has any words of experience or advice to share.

Thanks for reading.

Sounds like he was on the money. Strange though that you never had a PRV as my first guess would have been that it had failed. Get your second opinion, I would be interested to hear how it resolves.

Had the same problem n my old house, I think the solution was a simple "pressure reducing valve"  $100 for parts, an hour or two of the Plumbers time.

we have hi pressure in the 100 psi range... Don't really have a problem with our fixtures failing

also you would still have to replace the failed part in the shower valve.. If you get a hi quality valve then it should last a long time.  Part of normal maintenance 

terminator3 said:
we have hi pressure in the 100 psi range... Don't really have a problem with our fixtures failing

We had high pressure and had cartridges fail in 3 different faucets. PRV solved the problem. Guess it can be hit or miss.

on monday the 10th, I found our hot water heater spewing water. turns out the pressure was around 120psi and "fortunately" just blew the pressure release valve.  Had to have a pressure reducer installed and valve replaced (Thanks P. Masucci!).  He said we were lucky it didn't start blowing supply lines to the toilets (the couplings on newer ones are plastic, not metal). The high pressure wasn't a recent issue as I've always thought the system sounded louf whenever water was running. Anyway, former owner had put down a pergo floor over a portion of the basement floor. Since water got underneath I started to pull it up to drying things up, and come to find classic absestos tile underneath. Fun times.

just leave the asbestos and repair or replace the new floor.  That tile is not a problem if it stays there.

I can't speak to cost but a PRV is necessary to reduce that excessive pressure.

The expansion tank is also necessary once a PRV is installed.  

When a water heater heats up the water expands (excited molecules move faster and occupy more space than unexcited cold water molecules) and typically that added pressure is absorbed back into the water supply system including your internal plumbing and the much larger municipal plumbing system that brings water into your house.  It is generally not a problem.

When a PRV is installed it prevents the expansion back into the municipal system.  Instead your relatively small house plumbing system must deal with the added pressure from heated water. This is often times a problem.

The expansion tank is designed to ameliorate that expansion variable without putting the rest of your home's water distribution system at risk.

So you have two issues.

The street water pressure entering your house is dangerously high and needs to be controlled via a PRV.  Once the PRV is installed you need an expansion tank on your water heater to ensure the water heater doesn't create excessive pressure within your now isolated (via the PRV) house.

This is a somewhat typical problem around here.  

FilmCarp said:

just leave the asbestos and repair or replace the new floor.  That tile is not a problem if it stays there.

true, but there was sufficient cupping of tiles and tiles popping off the concrete to warrant removal.  Have gotten homeowners insurance to cover it

Thanks everyone - Alias, thanks for explaining the expansion tank. We are going to deal with it for sure, though for now we're hoping to just fix the shower and then circle back around to fix the larger issue. Too bad we can't use that extra water pressure to spin a little turbine and power our fridge or something.