Pressure issue

draven8795 · Jan 21, 2009

I have a shower that is at the end of the line of the main 3/4" cold and hot lines. I did a test and its only 30 psi. at the shower head.

I have a sand point well and a pump and it that reads between 40 and 50 psi when pumping usually closer to 40.

My question is why is my pressure so low at the shower? I have few things I would like to run past you.

When the cold and hot lines reduce to 1/2" and head toward the shower there are two 90 degree connectors on each of the 1/2" lines within a few inches of each other so that the pipe gets to the right spot before going up to the shower handles and head. Could this cause a loss in pressure with these bends in the pipe? I'm thinking of removing them and replacing with pex to get a nice smooth transition up and see if that helps

If this isn't it what else would cause such a drop of pressure? Things to check? Is it bad that my pump barely gets above 40psi when pumping?

Something else that might help determine a problem is that I have to turn the Hot all the way up and then turn the cold on a little to get a good water temp.

Thanks for all the help.

Jadnashua · Jan 21, 2009

What are the existing pipes made of? Was the pressure reading taken with water flowing or static? Pressure in the whole house should be the same unless some valves are turned on (well, it will go down a little with elevation, but not a huge amount and certainly not 10 pounds unless you live in a high-rise). Dont' confuse pressure and volume. Pressure will be the same in a soda straw as a fire hose, but you'll get a lot more volume out of the fire hose. If there is any galvanized plumbing in your lines, they could be the size of a soda straw inside. Maybe just a nipple or other fitting is all it could take. You may want to check any internal filters or screens in the showerhead or valve...they could be clogged, restricting the flow.

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draven8795 · Jan 22, 2009

The existing pipes are copper.

I took the reading with water flowing out of the sink both at a hose outlet right next to the pump which was 40psi with a sink flowing and I had a sink flowing in the bathroom when I took that pressure and read 30 at the shower head.

I'm wondering if the valves in the shower are possibly made of galvinized and maybe thats where the problem is occurring? I do have extremly hard water.

Am I under the right impression that copper pipe won't begin to close up but galvanized will?

Is it worth taking out the 90 degree pipe fittings to get a smoother run to the shower?

Ladiesman271 · Jan 22, 2009

draven8795 said:
Is it worth taking out the 90 degree pipe fittings to get a smoother run to the shower?

No. That would be a waste of time.

draven8795 · Jan 22, 2009

So bends in the pipe don't have anything to do with flow or pressure?

draven8795 · Jan 22, 2009

I'm going to be working on this problem this weekend anyone else have any thoughts or items to look at?

Ladiesman271 · Jan 22, 2009

draven8795 said:
Something else that might help determine a problem is that I have to turn the Hot all the way up and then turn the cold on a little to get a good water temp.

What does water temperature have to do with water pressure?

Measure the temperature of the hot water at the sink near the shower. My hot water temperature is in the 120 to 120 degree area. I mix in little cold water when I take a shower.

draven8795 · Jan 22, 2009

It doesn't have anything to do with pressure. I'm stating that I have to turn the hot valve all the way open and then just turn the cold valve a little as in the cold over powers the hot so I'm wondering if the problem of low pressure is possible coming from a clogged hot water line.

Or what are other reasons for having the hot valve fully open and only turning the cold valve slightly.

Ladiesman271 · Jan 22, 2009

draven8795 said:
It doesn't have anything to do with pressure. I'm stating that I have to turn the hot valve all the way open and then just turn the cold valve a little as in the cold over powers the hot so I'm wondering if the problem of low pressure is possible coming from a clogged hot water line.

Or what are other reasons for having the hot valve fully open and only turning the cold valve slightly.

Take a gallon size milk jug or a bucket and measure the amount of water that comes out of the shower head. Measure hot alone full open, and cold alone full open. Also measure the hot water temperature.

Measure the same thing at a sink. Fill up a pan and time the hot fill time and cold fill time.

Once you measure all of that, you will have some idea on what is going on.

CT · Jan 22, 2009

draven8795 said:
I have a shower that is at the end of the line of the main 3/4" cold and hot lines. I did a test and its only 30 psi. at the shower head.

I have a sand point well and a pump and it that reads between 40 and 50 psi when pumping usually closer to 40.

My question is why is my pressure so low at the shower? I have few things I would like to run past you.

What is the elevation difference between the pump and shower head? What is the length of pipe between these 2 points? Any backflow preventer in between? 3/4" copper pipe from pump to shower head?

Pressure drop from the two 90 degree elbows is small.

Jadnashua · Jan 22, 2009

You could have a problem with the heat traps or dielectric unions on the water heater...the opeing could be clogged up.

draven8795 · Jan 22, 2009

CT said:
What is the elevation difference between the pump and shower head? What is the length of pipe between these 2 points? Any backflow preventer in between? 3/4" copper pipe from pump to shower head?

Pressure drop from the two 90 degree elbows is small.

The elevation is about 15 feet or so Its only a one story and the the pump is in the basement. The distance is probably 50 feet from pump to shower.

draven8795 · Jan 22, 2009

jadnashua said:
You could have a problem with the heat traps or dielectric unions on the water heater...the opeing could be clogged up.

Would draining some water out of the heater help flush some of the stuff out?

draven8795 · Jan 22, 2009

Ladiesman271 said:
Take a gallon size milk jug or a bucket and measure the amount of water that comes out of the shower head. Measure hot alone full open, and cold alone full open. Also measure the hot water temperature.

Measure the same thing at a sink. Fill up a pan and time the hot fill time and cold fill time.

Once you measure all of that, you will have some idea on what is going on.

I did a bit of a test today and it didn't seem any different from cold to hot on the amount of flow or pressure that was coming out. I still need to check the valve assembly for the shower handles to see if its galvanized. Maybe the whole problem is there.

Ladiesman271 · Jan 23, 2009

draven8795 said:
I did a bit of a test today and it didn't seem any different from cold to hot on the amount of flow or pressure that was coming out. I still need to check the valve assembly for the shower handles to see if its galvanized. Maybe the whole problem is there.

Check the temperature of the hot water first!

Msgale · Jan 23, 2009

my copper supply pipes were partly filled...

...with a white deposit, in a hard water geographic area, ( not rust), and my low flow problem was fixed when i replaced about 10 feet of 1/2 inch copper.

draven8795 · Jan 23, 2009

Oh man thanks for the confirmation. The pipes are as old as the house (30 some years) and I have really hard water. I'll replace some of the pipe tonight and see if that helps. I'm going with pex instead and quick fit connectors.

EDIT: Although I guess this doesn't explain the PSI drop I just bought some new pex pipe for 20 bucks so I'm going to install it tonight to replace some of the pipe and see if anything changes.

Ladiesman271 · Jan 23, 2009

draven8795 said:
Oh man thanks for the confirmation. The pipes are as old as the house (30 some years) and I have really hard water. I'll replace some of the pipe tonight and see if that helps. I'm going with pex instead and quick fit connectors.

EDIT: Although I guess this doesn't explain the PSI drop I just bought some new pex pipe for 20 bucks so I'm going to install it tonight to replace some of the pipe and see if anything changes.

You are just guessing now. If that piece of pex does not work, then what do you do just keep replacing more copper with pex? Pex is not even legal to use for the water supply around here.

I thought that your problem was:

"Something else that might help determine a problem is that I have to turn the Hot all the way up and then turn the cold on a little to get a good water temp."

Does the water come out of your shower head fast enough or not? You measured the volume of water but did not state how many gallons per minute your shower puts out. The temperature of your water heater may be low, so you should verify the temperature of the hot water at any sink in the house before you mess with pipes. Your water heater could even be defective!

draven8795 · Jan 23, 2009

Ladiesman271 said:
You are just guessing now. If that piece of pex does not work, then what do you do just keep replacing more copper with pex? Pex is not even legal to use for the water supply around here.

I thought that your problem was:

"Something else that might help determine a problem is that I have to turn the Hot all the way up and then turn the cold on a little to get a good water temp."

Does the water come out of your shower head fast enough or not? You measured the volume of water but did not state how many gallons per minute your shower puts out. The temperature of your water heater may be low, so you should verify the temperature of the hot water at any sink in the house before you mess with pipes. Your water heater could even be defective!

My initial problem was basically why the shower isn't producing a good stream of water whether it be flow or pressure. I may have confused some terms. In doing some more research today I am still under the impression that my pipes have a build up in them.

I used the temparature item as an example to help explain my problem which i think clouded my original question. My water temparature is fine.

I'm going to take the pex and replace the 1/2 line going to the shower which is only 20 bucks (for 50 feet) and if that helps great then I didn't spend a bunch of money getting a plumber in there. If not I will replace the valves on the shower which would probably be another 60. If that fails then its probably time to call someone in. I'm also using that line to raise the shower head another foot since its really low. I was just looking for ideas of things to check that might cause bad flow and pressure. Maybe what I'm seeing is just bad flow and replacing clogged pipes will help this. For 20 bucks and another 15 for quick fit fittings I might as well try it.

Ladiesman271 · Jan 23, 2009

You said the hot and cold water each produce the same amount of flow per minute when you did your test. How many gallons per minute did you get in your test?

Your shower head can clog if you have hard water, so check that also.

Pressure issue

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