Hot water noise

[ajohansson]

New house to me but 15 year old. Two story slab on grade tract home in southern cal.

master bath is directly above kitchen if hot water is turned on down stairs in kitchen I can hear a strange sound in the wall of my shower near the valve. Shower is on an exterior wall but control valve is on a perpendicular wall. This is directly above the downstairs kitchen sink. Also if I turn on hot water in the sinks in the master bathroom I hear this same noise.SInks are about 8 feet away on opposite wall. As soon as water is turned off it stops. It is not a hammer or a knock but like a high then low pitch that repeats itself. I need to try and record the sound and put it on youtube tonight for you folks.

Any help appreciated.

AJ

 

[Smooky]

Make sure all the angle stops are fully open under your sinks and at the toilet etc and see if that helps. If you have any other inline valves make sure they are all fully open, there may be one at the hot water heater.

 

[Sponsor]

 

[Gary Swart]

It does sound like a valve is not fully opened. This is one reason 1/4 turn supply valves are wise.

 

[ajohansson]

Alright all valves are open and its only in the morning just tried to duplicate tonight.

It almost sounds like a small pump tryng to run like an rv water pump

 

[Reach4]

Alright all valves are open and its only in the morning just tried to duplicate tonight.

It almost sounds like a small pump tryng to run like an rv water pump

Run a faucet that causes the sounds. While the noise is happenig, go feel the pipes in and out of the WH. Feel a vibration? If not, try feeling other pipes including the incoming water and PRV if you have one.

 

[Jadnashua]

Do you have anything on a timer, like say maybe a hot water recirculation system that may start up in the morning? Maybe pressure related? Depending on how early in the morning, if it's before most people are up, the water pressure may be higher than later when lots more people are using water in the area. You have a typical tank-type WH and not a tankless system?

 

[ajohansson]

So its a traditional tank system actually has two tanks that are connected to each other.

So i looked for a prv and i cant find anything that resembles a residential style PRV you know with the bell style housing with the spring. I look to have a check valve at some point right before the water goes into the exterior wall. Maybe this is a pressurw thing. I know my master bath tub faucet CRANKS out water like niagra falls.

Nothing on a timer, will happen during the early morning and at night. I will check this
Weekend for day time operations. To mee seems like if the hot water has not ran in a while is when it happens. The other bathrooms upstairs dont seem to make it happen but i cant rule it out for sure.

Now i can hear that sound in the wall from downstairs by the kitchen sink to the bathroom shower above it.

If i feel the pipe to the dishwasher it feels like a pulsating vibration that is on cue with the high low sound i hear in the wall. In the bathroom i didnt feel the vibration. I have not got a chance to get out to the water heater to feel for any vibrations.

I can hear it make that noise when the washing machine runs and is using hot water, when dishwasher flows hot water, the kitchen and occasionally when my sinks in the master bath turn on hot. Whats weird is its consistent but not consistent enough. I hear it everyday but not everytime the hot water is on. If i hear it already making the sound if i open a master sink hot water it will do it but if it stops as soon as i shut off the sink hot water.

And to clarify the sound is in the wall that goes from down stairs kitchen to master bath on second floor. Exterior wall. I never here it in the laundry room but like i said if i run a load that is demanding hot water that wall over in the kitchen starts making that noise. The laudry room is 40 feet away and directly on the other side of the water heater in the garage. Physically its the closest fixture. I have no idea how its plumbed though.

It is so bizzare.

 

[ajohansson]

so an update. got a water pressure gauge and I'm 105 psi static at the inlet to the house. No PRV installed on the house just looks like a check valve maybe or could just be a union of sorts.

Checked hot water spigot at clothes washer which is right behind the wall of the hot water heater and its 100 psi.

Outside spigot in backyard is 90 psi.

Hot water heater has no thermal expansion tank.

So looks like i need to call a plumber to put in a thermal expansion tank and a PRV.

I have two hot water heaters in series. Do I just need one expansion tank or two?

AJ

 

[ajohansson]

oh but wait theres more!

So i go to my neighbors (I just met these folks as i moved in a couple weeks ago) and ask to see there water set up.

He tells me that thing that I think may be a check valve is a union and he replaced that part with a PRV however a couple years after he did it he was out at the meter in the front yard checking on something in the underground vault and noticed a PRV there right after the meter.

So he essentially has two PRVs. I check my vault and yup I have one. However because its sat in a humid underground vault the lock nut is frozen and it aint budging. Im gonna try some penetrating oil but its not looking promising. The nut is literally coming apart when i put a wrench on it.

So I'm thinking I just leave that PRV in place and put one where my neighbor did right at the entry point to the house in that spot where the union is. the benefit to the PRV in the street vault though is it would also reduce the pressure in my sprinkler manifold as its taking that full 105 psi. I could add another i guess on the irrigation line pretty easy.

regardless of those choices a Thermal expansion tank is needed and same question is one or two for the two water heaters that are running in series.

 

[ajohansson]

so i was looking at how much room i have in the vault and where the PRV is placed is a pain to remove. Looked at the wilkins/zurn repair kits and of course can't find a replacement bell as that nut is not coming off. I think for the price I buy a new valve, gut it and rebuild this one in place. 45 buck for the repair kit 92 for the valve and well I have the body left over but worth i think the trouble. this way all my plumbing is spared the high pressure. I will coat the adjustment bolt in some silicon grease to keep it from rusting maybe even put like a balloon over it with a rubber band to protect it from the high humidity in the vault.

 

[ajohansson]

so sorry for all these posts. Looks like the wilkins/zurn 600 is replaced with the 600 xl i hope this will work as a sacrifice for the parts i need. Secondly I am reading about PRVs that have bypass for thermal expansion. Not sure if the original 600 had that bypass thing or not but is it good enough or should i just of piece of mind put in the thermal expansion tank in at the water heater?

 

[Jadnashua]

If, say, your incoming water pressure is 105psi, when the WH runs after shutting the water off from say taking a shower, the pressure will rise to above 105psi before it can bypass the PRV. Is that what you really want? The goal is to keep the pressure at a relatively safe, constant pressure, not rise each time you use hot water! Put in an expansion tank. You only need one, and it should be on the cold, inlet side of the WH, with no shutoff valve between it and the first tank so it can always absorb the expanding water. A bypass might be somewhat useful if your expansion tank failed...it would keep it from getting above the supply pressure, but not for normal operations.

 

[Dj2]

You have to maintain a constant pressure in the house (50 to 75) regardless of the street pressure before the meter. I would eliminate the one malfunctioning PRV at the meter, and install a new one at the point where the main enters the house. Any PRV will work. Zurin is a popular brand in California because it was the first to comply with the recent no lead law. You may not need an expansion tank, determine that after you install a new PRV.

Old PRVs are not worth rebuilding, because parts (if available), time at plumbing outlets and time to rebuild will total more than a new PRV, and you may still have a lousy valve, no matter what you do. No plumber will waste his time on an old PRV which was buried in the ground for 15 years. Penny smart and Dollar stupid.

While you are doing it, make sure the shut off valve at the meter is functioning (stops all water flow). If not, contact your water supplier and ask them to install a new one.

 

[Jadnashua]

The only time you can get by without an expansion tank and you're not experiencing the pressure going up high enough to open the T&P valve is if you have a leak in your system that can relieve the pressure! You can consider a bypass on a PRV as a leak, if that helps, but it can't push back until the house water pressure is above the street pressure. Often a toilet fill valve may be that leak which may not make any noise, and the water ends up going down the drain unnoticed. A dripping faucet somewhere could do it as well. Well, if you have a pressure relief valve, that can do it as too, but then it would be draining water every time the WH runs, kind of a waste. If your plumbing fixtures are all tight and not leaking, when you have a closed system, put in an expansion tank to keep the pressure from rising due to thermal expansion. For practical purposes, copper pipe isn't elastic. The plastic water hoses or rubber ones feeding say the WM or faucets can swell and absorb some of that expansion, but it also puts lots more stress on them. There's a reason why ET and closed systems go together.

 

[ajohansson]

So read up some more and did the PRV job today. Read a great write uo on how to do the expansion tank myself and size it and get the pressure correct. Thought i would have time today but nope PRV was a bitch.

Thought i would dismantle the old one to pull it out because the concrete floor of the vault was too shallow to spin it out as its threaded on one end and union on the other. Who does this anyway? Installs something you cant remove. Bell housing was frozen on.

I decided to put the prv right back where the original was to protect everything past the meter. Since i could not spin it out i rented a demo hammer and chiseled the floor out around it. Had some trouble with union and tape and fitting yada but eventually got her to not leak and now at 50 psi best of all....noise is all gone in that wall when hot water runs.

I cleaned out that vault real well to no more dirt in there. Gonna do the TET on tuesday. Just went with pec sharbite pushon as its sooo easy and i aint no plumber dont want to sweat pipes.

Just so happy house is now not vulnerable with prv in. And will feel way better when TET goes in. Thanks all for your help.

This blog really helped me too.

http://www.stevejenkins.com/blog/2013/12/testing-and-replacing-a-hot-water-expansion-tank/

 

[ajohansson]

so get this the noise is back. this morning my son turns on hot water in his upstairs bath and I hear that water pump pulsating noise in my masterbath shower wall. I can duplicate on cue. Im pissed.

So i put back on the thinking cap.

I noticed that I really never had great hot water in my shower or the downstairs kitchen sink which is directly below it. The hot water in the shower was recently exacerbated by my new low flow shower head from high sierra which i do love. So i was already thinking about whats wrong with my shower hot water and wondering is all this connected and I come up with a theory which I will tell at the end of this post.

So I pull out my price-pfister stem and its on full hot (previous owner pulled out the adjuster stop to keep it cooler if need be).

I pull out the balancing cartridge and notice the orings are stuck on the back of the brass inlet body (sorry dont know thech term for that part)and they look malformed.

This is a series 08 valve body.

Off to home depot I get a new cartridge and voila I have hot water in my shower again. So I get to thinking to go check the downstairs kitchen sink to see if it has hot-water now and to see if my theory is right. I have full hot water now in downstairs kitchen faucet.

Here is my theory - That the cartridge was not sealing well at the back of the brass water inlet and allowing cold water to bleed over to the hot side.

That pulsating sound was made when a demand for hot water reduced the pressure in the line and the cold water was forcing itself by that small little section. This would explain why i could never really get hot water at my shower. It would also explain why the fixture right below it the kitchen never got hot as it was getting fed cold water by way of this valve which was actually closer to it than the water heater.

I will listen inventively when I get home tonight to see if that sound returns but for now I have full hot water at both fixtures and have not heard the sound in the wall.

Does this theory sound plausible?

AJ

 

[Jadnashua]

Yes, that sounds plausible. Good detective work finding it, and this should help some others in the future. Most designs only open up the cross-over when on, but some designs can allow it while the valve is turned off...sounds like yours is the latter.

 

[ajohansson]

yeah those 08 price-pfister valves have an opening at the back of the brass body that gonna be constantly on and separated by an oring at the back of the balancing cartridge assembly on both the hot and cold water. If they are damaged or the the cartridge not seated I would imagine water seeping by. Im 97.6% sure on this happening in my situation. Whats funny is i googled for this image for this post and it came up from a terrylove thread about these cartridges even funnier is the guy said how he was unaware how these worked and had water everywhere because he didnt shut off the water before removing the cover plate ring...well that happened to me! I wish I had this picture before hand!! I had no idea what brand this damn shower was as nothing is marked price-pfister. I thought there was a much different scenario going on behind the bonnet when I took that cover plate ring off. Just glad I already put the PRV in and had it at 50 psi. Can you imagine at 105 psi! Live and learn! These do have to be the easiest dang cartridges to work with though. Nothing to screw out etc.

 

[ajohansson]

Ok looked at the picture again and called price-pfister and wouldnt i have water out the showerhead if the oring was leaking?

Is my theory plausible without the shower head leaking? The whole thing is strange with the kitchen faucet now getting realy hot water and changing nothing there. My theory seams right but i would think if the oring was leaking water would come out the head. I guess an internal leak is possible in the cartridge which could bypass water.

 

[Cool Blue Harley]

Good forensic work. I had as customer with that exact valve. The pressures balancing assembly was defective. She was experiencing hot water in her cold piping through various fixtures. There was a direct cross connection between hot asnd cold distribution piping. Don't forget to charge your expansion tank to match the incoming reduced pressure. They usually ship at 35psi. Read the installation instructions. Keep isolation valve closed, cycle WH with relief for thermal expansion (slightly open faucet) open isolation valve to tank when WH reaches temperature.