Hello I'm Mike. I'll be glad to help you with this issue.
Is this a single handle tub faucet?
You will have to turn the water off to the house and remove the cartridge. While its out you will have to slowly turn the water on to the house to blow out the line. You will then have to clean the cartridge and re install it. if
if you still dont have any cold water after all of that then you will have to replace the cartridge
Is the cartridge located behind the tap in the wall?
its behind the handle and the trim plate thats flush on the wall
I think I see it, is it a large flathead screw about 1" in diameter?
not sure witch model you have. every brand a model are different. you will have to remove the handle first. then you can remove the face plate. the cartridge will be behind the face plate
make sure you turn the water off to the house before removing the cartridge
We are going to go try it can we get back to you?
yes. ill leave the question open. just come back to the site and go to your questions to reply
We unscrewed the screw and removed the cylinder behind it. The screen is now exposed but it wont come out of its brass housing. It almost seems like the screen isn't meant to come out but rather the whole housing needs to be removed and a new one soldered in? Any suggestions?
is this a moen valve?
we think so.
if it is a moen you really need a moen cartridge removal tool to remove it, but you can grab the end of the stem with a pair of pliers(careful not to crush it) and pull really hard to remove the cartridge
I'll try the pliers again.
is there a clip holding the cartridge in place
is the cartridge behind the tap valve itself or off to the side. Looking at your picture I think I took apart the wrong thing.
the cartridge is the part that comes out of the valve body that the handle attaches to. it should have either a retaining nut or a clip that holds it in place
ok I definitely took apart the wrong thing then. I'll try again and let you know how it turns out.
here is a breakdown that may help you out.
were you able to get it out?