Why My Shower Has No Pressure

Why a shower has no pressure can be caused by a few different reasons. Keeping this simple, what you should first determine if the shower is the only fixture with the problem. Look at the other fixtures in the home and the same bathroom as the affected shower and check the pressure/volume of the water coming out. Check the fixtures with several different fixtures running at once and see if the pressure/volume of the water coming out lessens with additional fixtures running. Check both hot and cold to see if there are any changes in the pressure/volume at the shower. If the pressure/volume of water is low at other fixtures in that bathroom and gets lower when additional fixtures are flowing the problem is much bigger than just the shower, and you should be looking at the water supply to that affected bathroom. If the pressure/volume is low throughout the house and gets lower with additional usage then even the supply of water from the well pump system or, city water main could be suspect. I would recommend the services of a good plumber if the water supply were determined to be the issue. The troubleshooting for this problem can be intensive with a high cost for misdiagnosis. For the purposes of this post we are going to assume the pressure/volume is okay on all the other fixtures and only the tub/shower is affected even with water running at other fixtures.

Shower Only

If your shower is a shower only, the first thing I would do is unscrew the showerhead from the shower arm. Once the showerhead is removed cross your fingers and hope for the easy fix. Turn on the shower and check the flow out of the shower arm, it should flow well and be similar to the flow from a garden hose or, slightly less. This would indicate a clogged showerhead, which is an easy fix. In the showerhead there is a restrictor, which limits the flow of the showerhead to 2.5 gallons per minute. Some newer water saving showerheads may have even less flow. This restrictor is a likely place for debris to be caught blocking the flow of water. After cleaning the debris out of the restrictor in many cases the flow is restored. In addition to the restrictor mineral deposits from hard water may also build up and restrict or, block the holes the water comes out of. Typically this would have appeared as differing flow out of the holes with some not flowing at all. Soaking the showerhead in CLR or, vinegar will typically remove the mineral deposits and restore flow in the showerhead. If there is not good flow from the shower arm shutting off the water and moving down to the mixer valve where defects such as debris blockages in the stem or cartridge area and possibly repairing the stems or, replacing the cartridge along with flushing out the valve. If there is no pressure/volume with the cartridge or stems removed while flushing you should probably consider the services of a plumber.

Tub/Shower

If you have a tub/shower you should consider the same fixes in the shower only but in addition you should examine if there is good pressure at the tub spout but not the showerhead. This can help isolate the problem. In addition you should also look at the diverter to make sure that the tub spout is almost completely shut off when the shower is running. Typically the tub spout should have a trickle when the shower is selected this allows the push or pull diverters to reset when the water is shut off. If the flow is still heavy when the shower is selected that can be the problem.

I hope this helps you with your problem and if you have any questions please leave a comment.

Comments

  1. Justin says

    I have a tub shower combo and I dont have any pressure coming out of the spout and the shower head. I have pressure coming out of the sink and toilet in that same bathroom, just the tub has very little pressure. When you put on the water the cold water has the most pressure. When you put the hot water its very slow but gets super hot. When you turn on the shower its just trickling out of the shower head and Also the spout. I have no idea how to fix this. Can anyone give me some info. Thanks.

    • says

      Hi Justin,

      You have something blocking the flow of hot water. I’m going to guess by the symptoms you describe that you have a single handle mixing valve that is pressure balanced. The pressure balanced valves have a feature where there is a valve that slides back and forth matching the pressure of the cold and hot supplies thus keeping the temperature usually within 3 degrees of the set temperature even when water is used elsewhere in the home. You can read about them here.

      I believe that your pressure balancing valve has become stuck and is in a position where the hot is almost shut off and the cold is on full. It would help if you knew what valve brand and model you have and could tell me. Sometimes it is as simple as replacing the cartridge other times it is a bit more complex depending on the brand and model.

      Redwood

      • Matt says

        Hi,

        I have the exact same issue as Justin. I don’t have any pressure coming out of the spout (hot AND cold). I have a hose that connects to the spout so there’s no line running up to a shower head. The sink right next to the tub has great pressure, just nothing from the tub spout. It’s a Moen dual handle system so I decided to shut the main off while I pulled the knobs and the stems. I then turned the main and ran the water. Some junk blew out of the lines and I had good pressure from the cold (not good at all from the hot), so I chose to cut out the galvanized pipe (house was built in 45) and replace with copper. I actually ran new copper almost down to the meter in the basement. A bit overkill I’ll admit, but I wasn’t sure how corroded the galvanized might be. I replaced the stems as well thinking something was gummed up inside them, but still no pressure.

        Again, with the lines wide open the cold seems to flow just fine, the hot is still struggling but I have some success given there’s all new piping. I’m convinced it’s the faucet and I’m under the assumption it’s made for a high pressure water line. I’m curious if there is an anti-scald feature built into this two-handle system. If so, perhaps it’s run its course.

        Thoughts?

        • says

          Hi Matt,
          That would depend on the model of the valve and if it has pressure balancing or not.
          Generally if one handle controls the hot and the other controls the cold the valve is not pressure balanced unless there is an external pressure balancing valve installed.

          I’d suspect that there is blockage(s) within the valve and possibly within the showerhead.
          How is the flow with the showerhead removed?
          There is no such thing as a bath tub valve for high pressure water lines, they are made for a maximum of 80 psi by plumbing code.
          Redwood

  2. Lizz says

    Hi,
    We have a tub/ shower combo. The water coming out of the spout has a lot of pressure. The hot water has less pressure throughout the house. However, there is little to no pressure out of the showerhead but when we take the showerhead off the water flows fine. We have tried to soak the showerhead and it worked a bit better but went back in about a week to what it had previously been!! Do you think it is the shower head or the hose?

    • says

      Hi Lizz
      When you disconnect the hose from the shower arm there is plenty of water so it could be either the hose or the showerhead.
      I would take the connection apart between the hose and the showerhead then see what you have,
      There should also be a restrictor there that may need cleaning.
      Redwood

  3. Joshua says

    Almost like our problem. We have good preasure at the tub/shower. But when we select shower mode, there is a trickle. House has old galvanized pipes that could be clogged with rust.

    • says

      Hi Joshua,
      Have you taken off the showerhead to check the flow out of the open pipe? That will let you know whether the shower riser is clogged with rust or if the problem is in the showerhead or restrictor.
      Redwood

  4. Kirk says

    Our bathtub is only giving us a little bit of hot water and cold water..running very slow also we have been having some problems with our bathtub being plugged up with hair etc… would the batub from being plugged cause the water to come out slow??? or does something need to be replaced???

    • Kirk says

      Oh and also I checked the water pipes and they are freezing …its been cold outside here in minnesota since sunday could one of our pipes be frozen and causing the water flow to slow??? how can this get fixed???

      • says

        Hi Kirk,
        Slow flow out of the faucet and shower would be unrelated to the slow drain as the only connection between the 2 systems is though the air between the spout or, showerhead and the drain. Freezing pipes may present a problem for both systems. I’d get the heat turned up and open any access to the pipes allowing heated air to get to the pipes. Take a hairdryer and follow the pipes to find the spot where they are exposed to the cold and get them thawed as soon as possible. You may be able to prevent the pipes from bursting if you get them thawed quick enough. If the problem is not frozen pipes write back for more information on a tub faucet problem.
        Redwood

Add Comment Register



Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>