Low Water Pressure in the House: Six Causes, Ranked by Likelihood
Low pressure has a short list of causes, and they are worth working through in order because the first two are free to check and the last one is expensive to ignore.
One fixture or the whole house?
This single question splits the problem in half. One slow tap is almost always a clogged aerator or a failing cartridge. Unscrew the aerator, rinse the screen, and try again before you do anything else.
If every fixture is weak, the problem is upstream of the house: the main valve, the regulator, the service line, or the meter.
Check both main valves fully open
After any plumbing work, a main valve or meter valve sometimes gets left partly closed. It is a two-minute check and it solves the problem more often than people expect.
A failing pressure regulator
Most Florida homes on city water have a pressure reducing valve near where the line enters. They fail gradually and typically fail low. A gauge on a hose bibb tells you immediately: normal static pressure is roughly 50 to 70 psi.
Above 80 psi is a problem in the other direction and will shorten the life of every fixture and the water heater.
Scale and corrosion in old pipe
Galvanized pipe closes up from the inside over decades. Pressure at the street tests fine while the house starves. If your home still has galvanized supply lines, that is usually the answer, and a repipe is the only real fix.
A hidden leak on the service line
A leak between the meter and the house drops pressure and raises the bill at the same time. Shut every fixture off and watch the meter. If it moves, water is escaping somewhere.
Water heater problems that look like pressure problems
If only hot water is weak, the issue is at the heater: a partly closed shut-off, a failing dip tube, or heavy sediment. Cold pressure being normal narrows it right down.
Water moving right now? Shut the main off first, then call (888) 809-6756. Dispatch is live open 24 hours, 7 days a week across every Florida city.