Intermittent low shower pressure after installing new mixer

We had our bathroom remodeled recently. The mixer-type shower valve was replaced with a Symmons Temptrol, and the shower head was replaced with a Speakman Anystream. (It previously had an older model Temptrol and Speakman.)

The shower pressure is considerably less now than it was before. Full hot or full cold makes no difference. A trickle of water comes out of the tub spigot when the shower runs, but I'm told this is normal, and is certainly not enough to account for the lost pressure. When the tub is running, pressure seems normal, though that's harder for me to judge. Water elsewhere in the house is OK, and we never had a problem in the previous 10 years in the house.

The interesting thing is that one day last week, I turned on the shower, and low and behold, it was operating at its old strong pressure. It was nice while it lasted, but the next day when I turned it on, it was weak again.

That makes me suspicious that something is awry with the diverter and/or pressure balancing mechanism, so that it isn't engaging fully in the shower position most of the time (but every once is OK). This could be way off-base, though. (I have no idea how these work internally.) Is there any way the valve could have been mis-installed?

Thanks in advance for any ideas!

Chris

Have you moved the diverter lever all the way to the shower side?

shower head

Take off the showerhead and see if there is dirt or something in it that might be clogging it.

@Redwood: Yes, I've fiddled with the diverter lever, moving it back and forth to see if it was fully engaged. It didn't seem to make a difference. However, the lever does feel quite loose: you can wiggle the external lever back and forth a 1/4" or so without actually moving the valve. I'm not sure if that's normal.

@onezee20: Since it worked with full pressure on one occasion, I have assumed that the showerhead is fine. But it's an easy thing to try, so I'll take a look.

I would agree the showerhead is a good place to start.

See what kind of flow you get with the showerhead removed...

Update:

I removed the showerhead and checked the flow. It wasn't great; the water just flowed straight down out of the pipe rather than projecting out a little ways (that's a bad description, but I think you know what I mean).

I checked for debris in the showerhead and removed a few tiny bits, but that had no effect.

I've been able to get an occasional higher-pressure shower, somewhat at random. Possibly (though I could be wrong) it's more likely to have good pressure if the diverter is already in the shower position when you turn on the water. Perhaps the force of the water flowing through the diverter mechanism helps push it fully to the shower position.

Is there any way the mixer control could have been installed incorrectly that would make it behave like this? It seems unlikely that it's defective as it's brand new. As I mentioned before the diverter level is a bit wiggly, but that could be normal for all I know.

Thanks,
Chris

nigelspleen said:

Update:

I removed the showerhead and checked the flow. It wasn't great; the water just flowed straight down out of the pipe rather than projecting out a little ways (that's a bad description, but I think you know what I mean).

I checked for debris in the showerhead and removed a few tiny bits, but that had no effect.

I've been able to get an occasional higher-pressure shower, somewhat at random. Possibly (though I could be wrong) it's more likely to have good pressure if the diverter is already in the shower position when you turn on the water. Perhaps the force of the water flowing through the diverter mechanism helps push it fully to the shower position.

Is there any way the mixer control could have been installed incorrectly that would make it behave like this? It seems unlikely that it's defective as it's brand new. As I mentioned before the diverter level is a bit wiggly, but that could be normal for all I know.

Thanks,
Chris

Click to expand...

Chris,
Are there any shutoff valves on the supply lines that use rubber washers as opposed to ball valves? When they are older they tend to decompose and when they are shut down, and then reopened, they can break into pieces.

If so it my very well be that a piece of rubber found its way into the shower control valve and it is partially blocking the flow.

Ask me how I know.



HE

pressure

You may be confusing the pressure balancing function. If one side or the other has a low pressure it REDUCES the other one to the same level, it cannot increase the pressure to make them both equal. SO if either the hot OR cold has a problem for some reason the total pressure/volume will be reduced. You have to find out where the reduction is taking place and correct it there.