Shower and Bath Single Control Cartridge

[Chris W]

The faucet / shower has very poor pressure in only one of our bathrooms. It utilizes a single control cartridge and regardless of the setting the pressure is very poor. Thinking the cartridge may have become clogged or something along those lines I bought and installed an exact replacement. Same result. I removed the valve again and turned the water back on and confirmed that I do have full water pressure to that specific location. Put new valve back in, turned water main back on and still have original low pressure to faucet / shower. The water barely trickles out.
Any help would REALLY be appreciated!

 

[Greenman]

Plugged shower head. Take it off, there should be a screen or flow restricter in the back, clean it out.

 

[Chris W]

Plugged shower head. Take it off, there should be a screen or flow restricter in the back, clean it out.

Completely removed shower head yesterday thinking the same thing. Inspected screen. No obstruction at all. Shower head is laying in the tub. Frustrating...

 

[boomerang]

Is this house new to you? If not, was the water flow adequate at one time but got worse as time went on?

 

[Chris W]

Is this house new to you? If not, was the water flow adequate at one time but got worse as time went on?

The house was built in 1950 and has iron pipes. I thought that there might be a rust deposit causing a blockage but water pressure is strong when the valve / cartridge is removed. I replaced the shower / bathtub fixtures and replaced the valve / cartridge at the same time. It worked perfectly when tested. It’s in my teenagers bathroom and they are no help and telling me when the water pressure started to die off. It doesn’t seem to matter if I reinsert the old valve or use the new one. Pressure disappears. Remove the valve and there is strong pressure.

 

[Chris W]

The house was built in 1950 and has iron pipes. I thought that there might be a rust deposit causing a blockage but water pressure is strong when the valve / cartridge is removed. I replaced the shower / bathtub fixtures and replaced the valve / cartridge at the same time. It worked perfectly when tested. It’s in my teenagers bathroom and they are no help and telling me when the water pressure started to die off. It doesn’t seem to matter if I reinsert the old valve or use the new one. Pressure disappears. Remove the valve and there is strong pressure.

***Note***
I replaced the fixtures about a year ago...

 

[Humpy]

It's possible that the new valve was clogged by the same source of debris that clogged the old one.

 

[boomerang]

The house was built in 1950 and has iron pipes. I thought that there might be a rust deposit causing a blockage but water pressure is strong when the valve / cartridge is removed. I replaced the shower / bathtub fixtures and replaced the valve / cartridge at the same time. It worked perfectly when tested. It’s in my teenagers bathroom and they are no help and telling me when the water pressure started to die off. It doesn’t seem to matter if I reinsert the old valve or use the new one. Pressure disappears. Remove the valve and there is strong pressure.

I'm sorry but I'm a bit confused. You say you replaced the fixtures and replaced the cartridge at the same time. That would make sense as a new fixture would contain a new cartridge. What's throwing me off is that few if any would mention them as separate components when replacing the whole fixture. I'm starting to think we might have a terminology problem.

However...

Pressure and volume are two different things. You have a volume (flow) problem. You can have good pressure but low flow.

I think you have an iron pipe problem. That wouldn't be a surprise after 67 years.

 

[C1]

Because the flow restriction involves both hot & cold sources (and that you have supposedly eliminated the shower neck), a guess is that something has gone wrong in the casting that houses the valve cartridge. Remove the valve cartridge and use a light to inspect the valve body casting for issues. With both the shower head & control cartridge removed, I would run a wire through the system from the shower head thru to the cartridge valve body (shouldnt be a very long run length) and ensure that the wire is seen to show up inside the valve body unrestricted.

You may end up having to replace the whole valve assembly which is a PITA. .

 

[feralkid]

Is there an anti-scald feature on this valve?

If so, it may need adjustment.

 

[Chris W]

Gonna double check the shower head pipe and insure it’s clear. Will also recheck the anti scald setting.
Stand by for news.
Thanks.