Water heater or plumbing?
When they're pointing at each other, who to believe? Any other possible causes? Thx
Answers:
Check at the inlet of the water heater(marked C). If there is a dielectric union, take it apart and check inside the fitting. They do get a "rust" buildup inside the fitting. Clean it out and tighten the fitting and turn the water back on. If that doesnt do it, check the pressure at the "pop off" It is at the top of the heater. Should have 45 lbs. there. If not, check farther back on the inlet water line for a restriction in a fitting.
Other answers:
Do you have city water? If not, and it's well water, it could be the well itself or the pressure tank.
Do you have city water? If not, and it's well water, it could be the well itself or the pressure tank.
In most hot water systems, you have a converter or reducer, that only lets so much cold water into the heater at a time. It will be on the cold water inlet side of the heater.
When I had the same problem, the converter was partially blocked with built up deposits. If you can locate it, replace it. Small cost.About $5.00, and you can sweat the unit on yourself, or get someone to do it for you.
Water systems, like electrical systems, are best analyzed using logic. Work your way from a point of good pressure, to a point where it drops off.
A plumber can also run an acid wash through the pipes, but I am pretty sure they will not do that to a heater.
Good Luck.
hot water heaters build up hard water deposits or calcium, the best way to increase water flow is to clean the "hard water" out, turn off the power, drain it, take out the heating elements an put a tube or hose in the hole an hook a shop-vac to it an suck out the bad stuff...
Also, hooking up a water softener keeps the bad stuff out.
Plumbing. If your galvanized meets directly with copper without a dielectric union then you probably have corrosion buildup inside your pipe where the two meet.