I have a instant hot water boiler, and have just replaced the shower mixer tap. the cold water pressure is really bad but the hot is normal, so i can only get a crappy slow shower. any suggestions as to why the cold is so bad?

Cheers

Simon

Linkback: https://www.plumbers.nz/q-and-a-baths-and-showers/64/shower-problems-ii/939/

Thanks for the quick reply.

I don't think that's the problem. Here's what I tried...

I have two identical mixers, one on the bath, the other on the shower. Last night, I swapped them, bath is fine on both, shower not fine on both. I even turned the mixer through 180degrees so hot and cold were reversed - same problem.

Shower is fed from same pipework runs as bath. When you feel the pipes at the mixer, and the mixer is set in the middle, the cold pipe starts getting hot, so obviously the cold pressure isn't what it should be, but in the same room, off literally the same pipe run?

Help - Please

Thanks Robbo,

I was on the verge of calling someone out and decided to take one last look and see if there was anything blocking the pipe.

Anyway, I connected a hose to the pipe and took it outside and turned on the mains...

At first, clean cold water came out  - not at the same pressure as the bath or vanity, then something odd happened, the water went hot!

Cut a long story short, there is a very small hot water tank in the kitchen, there is a prv on the cold feed. The cold supply for the shower is fed from after the prv, and not the same run of pipe in the bathroom that all the other pipes are on. So, after destroying the hallway wall, I've now fixed it, and can get back to grouting the floor tiles, something I should have had finished last week

Good old DIY 

Thats the problem, how many DIYers do you know who braze pipe joins? Not many thats for sure.
I did all mine with compression fittings simply because I know how to use them and I detest this plastic pipe crap, there's no skill involved, and from what I've seen, very little care used in installing it.

Quote from: Plumber on January 12, 2012, 04:29:51 PM

Good old DIY 

Thats the problem, how many DIYers do you know who braze pipe joins? Not many thats for sure.
I did all mine with compression fittings simply because I know how to use them and I detest this plastic pipe crap, there's no skill involved, and from what I've seen, very little care used in installing it.

a wall is the last place i would use a compression fitting...

insurance void...

undertaking illegal works...

cue the PGDB....                  meh - your unlicensed - they wont bother you!!

hi guys, yes no skill required!! for a start the skill required is (1) you will need to know which pipes go where (2) you will need the correct tools and you will know not to put compression joints in the wall, D.I.Y. will never die,cheers

hi guys/Roberto, we are not that important,cheers