Need thoughts, low water pressure issue.

I have a client that recently had low water pressure on the Hot side of his system. He changed out the water heater, and corrected the problem, only to find he now has low pressure on the COLD side of his system. The Hot side pressure issue went away. There are no shutoffs that are partially open, mainly 3/4 in CPVC plumbing, 8 year old 5 in well, which is running well ( no pun intended )

Any thoughts??

Probably some trash in various faucets, the water heater probably was not bad, the symptom just changed for some other reason leading him to believe a new water heater helped. Unless he has a check valve (recirc loop) then the pressure will easily transfer through the water heater to both sides.

On second thought, he may just have a bad pressure bladder on the well tank which causes a lot of pressure fluctuations while the pump is trying to keep up with the various random demands.

Sounds logical…trash in system. A plumber can back-flush the fixtures.

This is the only thing that seems logical to me, it makes no sense that it would start on the HOT side and end on the COLD side. BTW< the water heater change was incidental. And it is all the COLD side, even the toilets. I removed the airrators, not even a hint of junk. Im wondering if a chunk of something which WAS slowing pressure on the hot side, when the water heater was changed, fell backwards, and is now pluging the COLD side. But like Bruce said, the hot should backfeed pressure at least.

Not an approved method but I used to just bang on the pipes with water open, and that will often loosen the debris.