Sudden Drastic Water Pressure Increase?

**BDP** · 07-22-2008, 06:54 PM

This morning, I suddenly noticed a great increase in water pressure to all of the plumbing in the upper level of my home -- I'm not sure what caused it. At first it wasn't a big deal, just a change -- But the pressure is so great now that the shower and sinks are incredibly noisy, there's extremely loud noises coming from the pipes inside the wall (tough to describe, just, well, loud).

To make matters worse, the pressure is so great that the upstairs toilet now is spouting water from the top of the mechanism that refills the back reservoir (sorry I don't know the terminology). It shoots up like a geyser! Granted this may be exposing a weakness that I need to replace that part, but still, something is up with the water pressure.

Can anyone tell me what I might need to do to troubleshoot this or if there's a common problem that causes such symptoms? I dunno where to start (though if there's such a thing as a device that controls the water pressure where the water comes into my house, that's a good start, I have noticed the pipe noise I cited above for a few months now where the main water line comes into the house, but only for a few seconds after a toilet is flushed or sink run, etc).

By the way, turning the water valve about halfway on the toilet solved the geyser problem, telling me there's definitely too much water pressure all of a sudden!

Any help would be very much appreciated!

**Redwood** · 07-22-2008, 07:03 PM

It sounds like you better get a gauge and check your water pressure. They sell gauges that screw onto hose bibbs. It should read less than 80 PSI. If it reads higher than 80PSI. you need to install a Pressure Reducing Valve (PRV).

You may already have one installed that failed and that is why you were having the noise before. Replace it if thats the case.

**BDP** · 07-22-2008, 07:19 PM

Thanks so much for the speedy reply. I assume if I have a PRV installed it's under the house where the main line comes in? That's likely the culprit if so. Either way I'll get a tester tomorrow at one of the big box stores and hook it to the hose outlet, which is very close to the main line into the house.

If it is indeed the PRV, is that something an amateur plumber can handle or would you recommend I hire a pro? And if so any idea of around what that will run me? I realize we don't talk cost here, but maybe a time estimate would help me figure it out.

Thanks,

Brad

**Redwood** · 07-22-2008, 07:42 PM

THe PRV could be at any point after the meter. It depends on the pipe materials used and your ability to deal with them.

**wraujr** · 07-23-2008, 04:52 AM

I would also call you water department and check with neighbors. In my area the water dept. is pretty good about coming out and check their side. If you don't have a PRV, then maybe dept changed something, etc. that increased pressure, etc. My water dept. has never charged for a visit.

**BDP** · 07-23-2008, 05:00 AM

Originally Posted by wraujr

I would also call you water department and check with neighbors. In my area the water dept. is pretty good about coming out and check their side. If you don't have a PRV, then maybe dept changed something, etc. that increased pressure, etc. My water dept. has never charged for a visit.

Funny you should mention that! I just called, and guess what? They started what they call a "Gradual" water pressure increase 2 days ago in my area! So my suspicions were correct.

Since I have a relatively new home (~9 years) they say according to their diagrams I do have a PRV in my house where the water comes in. So my next step is to find it and see if I can adjust it. Is it possible that the PRV will just need to be turned down now that pressure has gone up?

They say since it's inside the house they (the water co) won't come out to fix any issues (seems unfair considering they are turning up the pressure without my needing it) but I'd need a plumber if the PRV is malfunctioning.

So, I guess later today I clean out the closet so I can get into the access and find the PRV - Is it possible if will be near the main value to turn the water on and off that comes into the house?

Thanks for all your help, very much!!!

hj · 07-23-2008, 05:41 AM

A PRV does not depend on the incoming water pressure for its setting. IF you have one, and the pressure is not staying at the set pressure, then you need a new one. Whether it is a DIY situation depends on how the old one is installed and how compatible the new one is. Usually the answer is that it is NOT a DIY project.

**BDP** · 07-23-2008, 06:57 AM

Wow, good point. So what you're saying is that if I had a PRV, and it was functioning correctly, it shouldn't have mattered that they turned up the pressure, as the PRV should have kept it the same for the house no matter what.

So basically, I either don't have a PRV at all, or my PRV is/was always malfunctioning and the pressure I'm getting is the pressure from the city supply, not under any control by me.

I guess I can still look and see if I have one -- Is it possible it was just set to "max" pressure and I was just always getting whatever was available, and I just need to dial it back?

Are we talking major bucks if I need to have a guy come out and install a PRV?

**Redwood** · 07-23-2008, 07:31 AM

It may never have been set properly if the pressure was below 80 PSI. at the time of installation however that is unlikely and chances are it has failed. Its worth trying though.

Figure cost on the PRV is about $200 + markup and whatever the going rate for labor is in your area about 1 1/2 - 2 hours depending on how far away the parts are.

**jadnashua** · 07-23-2008, 07:33 AM

The cost depends a lot on where the current one is, how easy it is to get to, and how it is connected. It also will somewhat depend on whether your shutoff valve still works and if access to the water company's shutoff is possible to access (some places will not let anyone but their employees touch the main shutoff and if you have to wait for them it means the plumber sits wasting time and therefore your money).

You need to know what the max pressure coming in is. There is a maximum pressure drop across a PRV, and in some (usually rare) circumstances, you need two in line to make the needed drop within range of both of them.

I'm not a pro, but I would guess you'd be lucky to get a replacement done for less than a couple of hours labor plus parts. If everything was straighforward, good acces, ideal situation, same sized part, it could be done much quicker, but that doesn't happen often. Copper and brass prices have skyrocketed over the last couple of years, so what might have cost $10 then might cost $40 now, so parts aren't cheap.

Have the plumber install an expansion tank if you don't have one, or at least check that the one you have is still good...9-years is starting to push it on the life of an average one. No reason to have to pay to call him back to fixt that once you fix the PRV.

**Redwood** · 07-23-2008, 08:41 AM

Good point Jadnashua!

The PRV creates a closed system and a thermal expansion tank for the water heater would be required.

**Southern Man** · 07-23-2008, 11:08 AM

Its possible that the PRV was originally set at a pressure equal to or higher than you've got now. Crank it down to 40 or so to see if it works, then set it to your desired pressure.

**Gary Swart** · 07-23-2008, 11:40 AM

First thing to get is a pressure gauge. Then determine if there is a PRV and if so, that it is working properly. Since you made no mention of a thermal expansion tank, I assume you do not have one. If you have a properly working PRV, you have to have an expansion tank or the T/P valve on your water heater will open every time the water heats. The tank must be air charged to the same pressure that the PRV is set.

**wraujr** · 07-23-2008, 12:21 PM

For informational purposes, I have a "closed" system without an expansion tank. The Watts 35B PRV that I have (as do their newer modesl) have a "Thermal Expansion" feature that if the house (downstream) pressure rises more than approx. 10PSI above city side, a relief valve opens to prevent over-pressure in the house. Only works if city pressure less than 150 PSI/

For example, my 13 year old system sits at 85 PSI, pretty much 24 hours a day (measured with Watts gauge with peak needle). Couldn't understand this until I called water dept. which said outside hydrant is designed/measured to be 79 PSI, so the 6 PSI difference is probably the trip level for the Watts Thermal Relief feature (spec sheet is 10 PSI TYPICAL). In 13 years my TPR has never tripped on HW heater which I assume is around 125PSI... So the Watts PRV is keeping my house system within 10 PSI of city.

I'm not saying thats the best design, just providing info that probably applies to many homes as the Watts PRV are fairly popular.....

hj · 07-23-2008, 12:21 PM

Put the gauge on the hose faucet and check the pressure, then open a bathtub faucet and see what the pressure is. If you have a PRV that is functioning to some degree the pressure will drop to its setting. Then close the bathtub. IF the pressure then increases you have a bad PRV. If the pressure remains constant during the above test you either do not have a PRV, or you have one that has completely failed.