No - you need a regulator installed. Partially closing a valve will reduce your flow rate, but it will not reduce your static pressure.

Hello aliceinwonderland, and thanks for your response back.. I want to preface this by saying I really don't know much about issues such as this, but I'm wondering (in this context) how flow and pressure are different.. By lowering the flow would it not also reduce the pressure on the hot water heater..? I could definitely be missing something here due to not knowing how this all works..

skyclad,

Pressure and volume are often confused. They are not the same thing.
Static pressure is the amount of force the water is applying to the walls of the pipes, etc. when no water is moving. It's measured in pounds per square inch (psi). Just like the air pressure on your car tires.

Volume of water (flow rate) is the quantity of water moving through the pipe or fixture. It's measured in gallons per minute (gpm). The same pipe will deliver a larger volume of water if its under more pressure -- and that's why the two are often confused.

Static pressure is not reduced by partially closing a valve. That will reduce the flow rate when a faucet is open, but when the faucet is closed the pressure (static pressure) will quickly increase until it matches on both sides of the partially closed valve.

Residential plumbing systems are designed to operate at maximum working pressures of 100 psi or less. When you get 80 psi or above, you must install a pressure limiting device called a pressure reducing valve (PRV) that will limit the amount of water pressure.

When you install a PRV you must also install an expansion tank for your water heater.

I don't know the details of your situation, but normally, if it is required, the PRV is installed first thing where the water enters the building.

Do you know what the pressure reading was when the city came out?

Hi Jake The Wonderdog and thanks for that clarification.. The more I thought about it, I was beginning to see the difference.. Thank you for that explanation!

I'm missing several of the details of our situation here since my girlfriend was the one here when the city came by (she's not here now).. All I know is that it was definitely high according to the guy who checked it.....

Thanks again for your help on the pressure issue!

Checking the pressure is a simple DIY task with a gauge from Home Depot/Lowes/etal which you connect to the hose bib closest to the water meter. Over 85 psi is not recommended for the home and may call for a household PRV and expansion tank.

HOWEVER, that does not sound like your main problem here.

The T&P (temperature and pressure) safety valve on your water heater is designed to open at 150 psi water pressure, or boiling point water temperature, to prevent a catastrophic rupture of the water heater tank. The T&P would be gushing at this point, not hissing.

The T&P valve may be leaking due to being disturbed by the work that the plumber was doing. A bit of calcium could be caught in it and keeping it from seating completely. I would pull up the lever on the T&P for a second (catching the water in a bucket) then releasing it to let it close. If the leak stops, you're back to pre-plumber conditions. If it still leaks, it's time to replace the T&P.

randy427 Two issues: 1. The OP stated that the "water pressure" as he experiences it from the shower, etc is much higher. 2. The city came out and confirmed the pressure was excessive.

We see leaking TP valves when the static pressure to the home is excessive all the time. It's often times THE visible indicator that something's wrong.

It would have been good to get the actual reading from the City. But given the OP has stated that he is new to this - a plumber seems reasonable to check the static pressure and perhaps understand why this would have changed (is there already a PRV installed and it was adjusted, for example).

I do want to thank all you guys for your info and input on this.. I do realize the potential danger of a hot water heater malfunctioning.. I am in the process of getting some of the missing info tonight and will post a bit later.........hopefully to explain all of this more fully.. In the meantime, I want to post a picture of something the worker installed that day on the top of the water heater.. I do not know what this is called, but I'll bet you guys will know.. Thanks again for the info and help on this, and I'll be posting more info as I get it....

It's an expansion tank. It has a rubber bladder in the middle, with one side filled with air. When there are temperature increases in your water, pressure can build up higher than normal in the piping and cause damage. When you have an expansion tank, the bladder in the tank moves to compress the air side and the pressure is stabilized. It's a good thing to have (in fact, required in many jurisdictions), but it does not fix high water pressure problems. For that you need to have a pressure reducing valve (PRV) installed.

P.S.: Are you sure you have the straight story about what the water department folks said? There should be no reason to be digging up pipes to deal with a high pressure issue; a PRV installed in the piping where the water comes in to the house is the way to deal with that. And the PRV needs to be in an accessible location, because they have a useful life of about 10 years before the innards need to be refurbished, so its not something that one would bury.

So earlier I said you need a PRV and an expansion tank on your water heater. That's the expansion tank I was talking about.

I think that Kudzu mis-spoke. He said, "For that you need to have a pressure relief valve installed." I believe he intended to say a Pressure Reducing Valve (PRV).

Can you tell us what prompted the installation of that expansion tank? We haven't really gotten the answer to why this happened after the plumbers visited.

Also, do you have anything that looks like one of the following on your water supply, usually where it enters the house?

Jake-

Thanks for catching that. I corrected it above. I shouldn't post after my first beer of the evening...

Regarding the images above, we have not seen these and therefore don't know where they might be located (see story below regarding the "digging issue")..

So, I got with my girlfriend last night to get the full story on the water heater issue.. Some of this I didn't remember or didn't know, as I wasn't privy to the phone calls she had with various folks..

In the beginning of it all, our relatively new water heater was hissing from the pressure valve and also the gas burner seemed to be stuck on for some reason.. This went on for almost 2 days before we noticed the gas part being constantly on.........which resulted in a huge gas bill as you can probably imagine....:/ The worker from a local company came by whom we bought the water heater from not that long ago........turned off the water and then began working on the water heater.. He became unsure how to proceed at one point so called the office, talking to the owner I presume, then proceeded to install the above (see pic).. He finished the installation, turned the water back on then left.. I did notice the water pressure within the house being higher than before when washing dishes, etc.. Shortly thereafter we noticed that the pressure valve was still hissing (although the gas part was off now.......a very good thing..).. We called them back immediately upon noticing this and after talking to the receptionist (who was very nice) I was referred to the owner.. He said there was most certainly a water pressure issue from outside and since that was beyond their control (he was not nearly this cordial in his response) they were not coming back to do further work..........without charging us further of course.... Keep in mind this is who we bought the WHeater from to begin with.. We were not pleased!! Seeing we were getting nowhere with this guy, we called the city and they did a pressure check.. The guy that checked it said the pressures were 140-150, and that normal was around 130.. It was this guy (the city employee from water company) that said they would most likely have to dig up some of the line in order to find the "pressure regulator".. Said it could be under the house, but most likely would have to do some digging........implying it was likely underground..

Given all the above, we still are having the hissing issue from the pressure release valve.. The gas comes on periodically even though we aren't running any hot water at the time (thoughts on this part?).. We are unsure where to go from here since we obviously want to avoid the "digging issue" he mentioned if at all possible....

So, that is the full story to the best of my knowledge.. I'd welcome any suggestions/comments on all of this as to how you would proceed if you were us.. You guys have been very helpful so far.. I thank you....!

Wow! ok...

So here's what you need to know:

1. The maximum working pressure limit on the tank is 150 psi. That is also the point at which the pressure relief valve opens. While the water heater tank is rated at 150 psi max working pressure, other plumbing may be rated at 100 psi. Having 130 - 150 psi in your home is not normal or safe. You risk a catastrophic failure of your water heater or other plumbing component.

2. Anything above 80 psi must be regulated down to something at or below 80 psi.

3. You very likely have a PRV installed someplace, because the pressure from the City was always above 80 psi and you had lower pressure before.

4. I think what your plumber did was unprofessional, but just because they sold you the water heater that does not mean they are responsible for everything else. The unprofessional part comes from them not testing the static pressure when they see a leaking T&P valve. In addition, an expansion tank is always required when a PRV is present and they should have determined that from the beginning or installed an expansion tank if they couldn't determine it. Again, they aren't responsible for troubleshooting your pressure problems but they had a responsibility to test for the issue.

You need to get a plumber in there ASAP who can find the PRV and replace it.

Can you post a photo of your T&P valve on the side of your water heater - including the end of the pipe where water exits?

As for the burner coming on when water isn't being used, some amount of that is normal - but if you are leaking water out the T&P because of static pressure, you could be running the burner more often.

Right now, the burner running periodically isn't my concern. The pressure issue needs to be resolved right away and then determine if the water heater is behaving normally.

As jake explained in his last post,the fly in the ointment is a sorry plumber. Hire one that know's what he's doing and work's for a company not in business to rip customers off. I've said it before and will say it agin,"by and large,plumbers chase cars and lick themselves when they aren't out screwing customers." There's no excuse for why plumber didn't give you a written summary when heater was installed and agin when they worked on heater.

Hi Jake and thanks for the info.. We are in the process of getting a friend over here that used to work for the

Hi, I was looking more for the other end of that pipe that goes down.

Not sure if I can help you much there Jake, as it appears to go down a bit then wind around to the left and down......behind the water heater.. See pic..

skyclad So that was part of the purpose in asking.

The T&P valve (and discharge tube) is the last line of defense against a malfunctioning water heater that has the ability to level your house. There are specific plumbing codes that apply to the discharge tube.

I'm not a code expert on this - but I believe some versions of the code prohibit flex pipe. In addition we can't see how this is terminated.

Best practices say this needs to terminate in an air gap that is visible to the homeowner so that they know something is wrong. Code says "in the same room".

You have had a couple of problems with this water heater - both excessive pressure and a gas valve stuck on. You heard the water discharging from the discharge tube, but you didn't see it.

No way I'd be ok with that discharge tube setup - particularly since I can't see how it was done and the flex tube looks Micky Mouse to me.

skyclad-

Let me again point out that a Pressure Reduction Valve (PRV) should not be buried and the city telling you that lines would have to be dug up sounds entirely bogus. PRV's do not last forever because they have an internal diaphragm that needs to be refurbished periodically (typically every 10 years or so). There is also an adjustment screw that you have to set to get the correct pressure, and sometimes you need to reset it if the supply pressure changes significantly. I'm not saying it's impossible that someone buried it -- in the concrete or behind some sheetrock -- but only an imbecile would do so. You may have a PRV somewhere and just be unaware of it. Or there might not be one, and you will need to have one installed.

Finally, when the employee told you 130 PSI was "normal," all that means is that could be the normal supply pressure, not that it would be ok to have that pressure inside the house. Regardless of whether it's 150, or 130 or even 100 psi, as Jake said, you've got to get it adjusted down to no more than 80 psi.

Really wanted to say thanks for all the info you guys have provided on the issue I've got going on here.. We're taking care of it all now and in no small part as a results of your comments and help.. Much appreciated!!!

Let us know how it turned out.

Good luck. Please post back when you make progress, or if you have more questions.

P.S.: I once was helping a friend who was having similar problems and we finally found the PRV hidden in the corner behind the water heater. You needed to uninstall the water heater to get access to service the valve! I have no idea how that passed inspection. Just saying that might be one more place to look for your PRV.

If I were going in blind trying to locate the pressure regulating valve (if one is present) I would first probe/dig near outdoor faucet and/or shutoff valve where main line enter's home. Ordinarilly,I expect to find a concrete or plastic box containing shutoff and prv. I'll throw one last thing into this. DO NOT PLUG THAT RELIEF VALVE because as Jake mentioned,the heater could then possibly level your house.