First off, I know very little about plumbing so please excuse my ignorance.

My father and I changed and relocated my hot water heater back in December. We had to change it’s location from the attic to the garage as there was no easy way to get a new HWH into the attic without tearing up ceilings. The HWH was obviously installed before the walls/roof/ceilings were finished. In removing the old HWH we drained the contents through the HW lines in the house. I’m assuming that because of this, it may have clogged some of the valves and the ‘mixer pipe’ with debris.

In our master bath we have both a shower stall and a tub. The shower works fine but the tub has had restricted water flow since we did the work with the HWH. Something was blocked so bad that I could not get any HW out of the tub until I blew/sucked out a bunch of junk between the valve and the discharge pipe/faucet. Today my wife was trying to pull the plunger for blocking the pipe so that the water would come out of the showerhead in the tub. The water pressure was not enough to hold the plunger up.

I have plenty of water coming out of the valves when the stems are not in place. Yes, enough to flood the bathroom in a short amount of time.

What I am talking about is the small pipe that the water flows through when it leaves the valve on way to the faucet discharge. I had to blow/suck the valve/faucet discharge to get a bunch of gunk out when I initially had this problem. It was so clogged that no water was coming out of the hot side at all. I’d like to somehow clean this piece of pipe but don’t know if there is some sort of cleaner or gadget that I could use to do so.

Is there some sort of device I can use to clean between the valve (or whatever it’s called that the water flows through when the handle is opened) and the faucet discharge?

Your help is greatly appreciated!