Wierd Water Pressure Change

[faucetfluster]

I have a ~3500 square foot home with municipal plumbing which feeds through a pressure regulator.

For the last 10 years that I've lived here, there has been a very slight noticable shift in water pressure in the upstairs shower when a toilet gets flushed.

Recently, if a toilet gets flushed, the shower pressure drops to almost nothing, and won't come back quickly unless you stop and start it again.

I inspected for leaks in and around the house, and I haven't found any. I do have an in-ground pool in the back yard, and I have no idea how to tell if it's draining and filling, but that's the only thing I can think of.

I attached a pressure gauge to the outside pipe just past the pressure regulator, and it reads at slightly over 110 PSI. I went to the back yard and checked there, and the reading is the same. I've read that 80PSI is the max, but I'm wondering if the size of my home or the fact that I'm on a big hill with a two story house requires a higher pressure.

Also, in my office which is right next to the main water input, I can hear when people are showering or toilets are flushing. It's not a knocking or rattling, but just the noise of the water flowing through. Recently as well, the noise has gotten louder, and it seems like toilet flushes are taking longer to fill.

My wife tells me that the water bill was double normal last month, but she thinks that has to do with an accidental setting on the sprinkler timers (the gardener enabled watering twice a day instead of once).

Visual inspection of floors, ceilings, and walls around the interior show no signs of a leak thus far. If it matters, the water heater is ~10 years old, and about a month ago we had our drains snaked because of a clogging disaster that filled our bathtub with unmentionable waste.

What could possibly be happening?

 

[LiQuId]

110 psi is high, you should have your pressure reducing valve checked... other than this I am ( for the time being ) at a loss to explain this.

I am writing so that I can stay on track when somebody has a better insight and I can learn.

 

[johnjh2o]

Instead of repeating myself I believe you may have the same problem.

http://www.plumbingforums.com/forum/f2/occasional-low-hot-water-pressure-2128/

John

 

[faucetfluster]

This was exactly my problem. Funny enough, my neighbors are experiencing the same problem, so this was a double whammy.

I set out to replace the pressure reducing valve / pressure regulator myself, which turned out to be one heck of a project. After about a day and 9 trips to home depot, I finally caved and hired a pro to finish the job for me. I had no experience soldering copper pipes, and while I think I did a good job getting as far as I did, I could not desolder the feed pipe coming out of my house, and I didn't have a great deal of faith that my soldered joints would prove to be water-tight.

The plumber did give me a good tip. The pipe that needed to be de-soldered was still dripping water after > 24/ hours. We flushed all the toilets in the house and opened up the back yard hose bib and both an upstairs and downstairs sink. The pipe drained properly after maybe 5 minutes of that.

Even though I had the same brand and same size pressure reducing valve, over the years the manufacturer changed the threading just slightly such that the newer model would not properly connect in place of the old model. Sometime in the next month or two, I'm going to buy another pressure reducing valve as a backup for the time years from now when it needs to be replaced again.

The new valve is pushing out only 50psi (compared to the 110 that I was seeing), and that does not seem to be a problem at all. The noise from water in my office is almost completely gone when sprinklers come on and when toilets get flushed. I had no idea that was any sort of problem until now. For 10 years I've been hearing it - I'm imagining it was because the pressure was set too high originally, and became much worse as the valve itself stopped operating correctly. The silence is beautiful.

In the end, I spend maybe $200 trying to fix it myself (the valve was ~$100, plus a torch, fittings, pipe cutters, some pipe wrenches), and the plumber charged me $200 to complete the job on a saturday. Still less than the $500 I was expecting from reading various places around the web and I picked up some new tools, some experience, and a better understanding of plumbing in general.

Thanks for your help guys!