Shower - Low Pressure and scalding hot at times

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HemiMoparGuy1981

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Hey Guys,

I'm having some issues with a house I just bought. The shower is a little on the low side of pressure. There are times it drops even lower at random. I figure it is the pump catching up, but hard to troubleshoot when I'm butt-naked and wet. More of an issue though, is any time any other water in the house is used, especially flushing the toilet while in the shower, I get scalded. I figure it has to do with something else robbing the cold water supply and getting practically straight hot water coming out, until the toilet is full or the other faucet gets shut off, or I scream at the wife to turn the washer or dishwasher off (can't hardly get her to do dishes or laundry, but when she finally gets off her butt to take care of it is when I am in the shower...but I'm not here to ask advice about her.) THEN, it takes a while for the water temp to restabilize.

Preventing scalding hot water from usage elsewhere in the house is my main concern...but if I could also get more pressure the full time in the shower, that would be super. So, where should I start? Any help is greatly appreciated.

Thank You in Advance,

Eric
 

WorthFlorida

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A picture of the shower/tub valve unless you know it and about how old?
What size pump and pressure tank?
Have you checked the pressure tank?
What is the temperature set for at the water heater? (The WH may have been adjusted to a too hot setting (above 120 degrees) to compensate for poor performance of the water heater or low pressure?)
What type of water heater?
Typically what type of pipe and size.
 

Terry

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When was the home built?
How many bathrooms?
What do you have for water lines? Galvanized Steel, Copper, CPVC, PEX

How about a picture of your shower valve 800 pixels or less.
 

Jadnashua

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For decades now, all shower valves have had to have anti-scald tech. If yours has it, it's not working properly. If not, do yourself a favor and make the life of the whole family safer and replace or fix the valve with one with anti-scald tech.
 

HemiMoparGuy1981

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A picture of the shower/tub valve unless you know it and about how old?
What size pump and pressure tank?
Have you checked the pressure tank?
What is the temperature set for at the water heater? (The WH may have been adjusted to a too hot setting (above 120 degrees) to compensate for poor performance of the water heater or low pressure?)
What type of water heater?
Typically what type of pipe and size.


Not sure on pump right now...but I do know it is a shallow pump outside in a hole with a small wellhouse built around it.

Not sure on size of pressure tank, but included a pic. There is some moisture around the tank, so I suspect a slight leak, but it could be the water heater leaking as the moisture is literally right between them.

Water heater is about 30 gallon electric. I forgot to check the temp setting, but at this point I doubt is the culprit, I think it's in pressure and cold water being consumed so the only water I get is hot water. NEVER had an issue when showering when home alone, or when up early and family still in bed.

Pipe going into tank looks to be 3/4 galv. Coming out is 3/4 CPVC but reduces to 1/2 CPVC immediately before going to any fixture or device.
 

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Terry

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The tub/shower needs it's own 1/2" line off of a 3/4" from the water heater. You can also feed the lave with that same line, but nothing else.
For the cold in that bathroom, it's 3/4" which then breaks down to 1/2" feeds for the shower and the tub. Your piping is undersized.

Adding a single handle pressurized valve would help, but you still have the issue with not enough volume to the shower.
 

HemiMoparGuy1981

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The tub/shower needs it's own 1/2" line off of a 3/4" from the water heater. You can also feed the lave with that same line, but nothing else.
For the cold in that bathroom, it's 3/4" which then breaks down to 1/2" feeds for the shower and the tub. Your piping is undersized.

Adding a single handle pressurized valve would help, but you still have the issue with not enough volume to the shower.

Yup, this seems like the first/main stage of the problem. The plumbing was definitely redone by a previous home owner, because it is all very chincy, pipe just dangling with no straps. It literally changes to 1/2 with reducer in the vertical pipe coming out of tank then everything else it teed from that single run...So in my recent case, the washer was running, so it was drawing warm water...I did just flush the toilet before jumping in shower and it is an older toilet that uses the 3.5 gallons to flush and needed to be filled, plus the water heater was trying to fill up all at the same time.

So it sounds like I have a plumbing project to jump ahead on. I had plans anyway, as there is a bathroom that will be going upstairs that needs refed, plus I want to move the washer and kitchen sink for the kitchen remodel. The upstairs bath is far down the list, kitchen is first as there are no cabinets besides the sink base. But sounds like I might as well just replumb the entire house, as at least everything is pretty central. Bathrooms are literally on top of each other, Tank and water heater are next to basement steps, Kitchen is on one side of the steps, Bathrooms just on other side. Very minimal extra to just do it all at once.

So just to clarify, I want 3/4 cold going everywhere, and tee off in 1/2 for each individual fixture? Is it wise to run 3/4 directly to WH and washer to save fill time?
 

WorthFlorida

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You do not have a anti scalding faucet and that is a very old pressure tank that has no bladder to separate the air and water. The pressure tank is probably full of water with little or no air in it for proper operation.
 

Fitter30

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If the toilet is fed from the run of the tee and shower is fed from the bull thats a problem. If there is a cpvc shut off valve for the bath thats more restriction in the cold line. Needs to be a full port or up size to 3/4" with adapters .
 

Reach4

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I'm having some issues with a house I just bought. The shower is a little on the low side of pressure. There are times it drops even lower at random. I figure it is the pump catching up, but hard to troubleshoot when I'm butt-naked and wet.
Set up your cellphone camera to take a movie of the pressure gauge. Then take your shower. Similarly, you could attach a garden hose thread pressure gauge to the drain of your WH, and take that movie as you shower. That would show up restrictions before the WH. Also, the difference in pressure between the gauge at the pressure switch and the WH during flow conditions could tell you more.

There are repiping solutions available, but you might gain some free improvement by turning up the pressure switch setting, and adjusting the air precharge in the pressure tank accordingly.

This is not to say that a repipe is not in order. Running 3/4 to the washer is not wise. Toilet and lavatory can be run in 3/8 or 1/2. Running a dedicated 3/8 hot from near the WH to the lavatory would shorten the wait for hot. Running a 3/4 for hot to a bathroom would lengthen the wait for hot for a shower.
 
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Terry

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For a two bath home you normally have 1" at the beginning, with 3/4" to and from the water heater.
Each bathroom gets it's own 1/2" hot. You can supply the cold to two bathrooms with 3/4".
 
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