Hi, I have always had low hot water pressure in my master shower ever since the house was renovated. I have followed the advice on this site, and it is clear that it is a clog in the hot water line. I then decided that it would be brilliant to shove a semi soft plastic homemade snake device down this pipe to hopefully loosen whatever it is that is clogging the line. Of course I now have made it worse. That's what I get for thinking! Now there is hardly any pressure at all! Hot or cold. Please help!!

What's the brand name of your shower valve? One handle or two knobs? How old? Tell me more about this "snake" you ran in the pipe? What pipe was it? Regards, Tom

I just realized I mis spoke, it is not the inlet valve, it is the hot water line that is clogged. Water is barely trickling out of the hot water side.

The shower is one knob, Delta Monitor 1400 series, I don't see a name on the valve but it looks like a Thermostatic? (I compared it to one online). I used a really long plastic zip tie. I pushed it down the copper pipe on the left, this is where my hot water was coming out from. I got it through one elbow but could not get it past what felt like another elbow.

I just replaced the cartridge, it had a crack in it. The cold is now working great but the hot water is still trickling out.

I tried backwashing it but I don't think I did it right. The shower is 2 years old, I had all new plumbing installed, all new copper pipes and new water heater.

Thank you so much for your time.

Sounds like you have a blockage in the hot water supply. To backflush you must shut the water off to the heater and connect a air compressor or a air tank to the hot water supply. Now drain out 5 or 10 gallons out of the heater to accommodate the air and turn on the compressor or open the air tank. This should blow the crud back into the heater where it can be flushed out. But all this isn't going to do much good unless you flush your heater on a regular basis. Let me show you how.
For long life and fewer troubles you should keep your heater clear of mineral build-up by flushing on a regular schedule. Attach a hose to the boiler drain at the bottom of the tank. With the pressure on, open the boiler drain and let it run until the water runs clear. You will see a spurt of red,(rust) followed by white or yellow grains,(lime or calcium carbonate). This shouldn't take more then a few minutes. Do this monthly to keep it clear. Don't forget to flush it out every month. Your heater will thank you for it. Hope this helps, Tom