If there's an accumulation of sediments in your hot water tank, it can lower your water pressure. The presence of kinks in the flexible water pipes used in water heaters can result in low water pressure. If the shut-off valve isn't fully open, water pressure can drop.
Partially Closed Valve
One of the most common issues that can lead to low water pressure problems is that the water is being obstructed by one or more partially closed shutoff valves. Typically, a home will have one main shutoff valve located inside the house.
If you're suddenly getting low water pressure in one area of the house… ...the supply pipes to that area may either be corroded, leaking or blocked. If all the fixtures in an entire bathroom or the entire kitchen are suddenly getting low water pressure, you can trace the issue to the plumbing pipes.
If the hot water pressure is low, but the cold is fine: You may have sediment and limescale build-up in the pipes or faucet, or it could be caused by a partially closed or restricted shutoff valve.
Buildup throughout the water supply commonly causes low hot and cold water pressure. Sediment or mineral buildup happens in pipes or water tanks when hard water deposits minerals or sediments over time. Sediment and mineral deposits build up and damage plumbing lines by creating blockages or corroding metal.
#2 Your Heater DOES Affect Water Pressure
There are two types of water heating systems. The way each system heats water affects your water pressure.
The two options to fix this problem is to either have your plumber clean the water supply lines or replace them with new water pipes. Sediment and scale buildup inside the water heater. If your water heater is not that old, you could have your plumber flush and clean the sediment and scale from inside the tank.
If you have low water pressure in all your plumbing fixtures, the issue is almost definitely with your water supply or your pipes. However, if it's one or a few fixtures that seem to have a low flow, you may want to check out the fixtures.
The most common cause of low shower pressure is a blocked showerhead, as a result of limescale build-up. These blockages obstruct the water flow, leading to reduced pressure over time. Most showers are fitted with a filter, protecting the pipework from debris, but this can become partially blocked by scale.
Pressure loss can be a serious threat to public health. A reduction or loss of pressure in the distribution system can result in backflow, allowing contaminants to enter drinking water through unprotected cross-connections.
If the municipal water or well-water flow is the problem, hire a licensed plumbing contractor to install a water-pressure booster pump. These powerful, electric pumps target incoming pressure and raise it to the proper level.
The most common cause of poor water pressure in the home is blockage somewhere in your sewer line. If your home's septic system includes a private septic tank, call a plumbing specialist to inspect your home's tank to see if the unit needs to be drained.
The city could be flushing hydrants.
In any of these cases, the pressure loss will be temporary. But when the water does come back online, it will definitely kick up sediment, which can clog supply valves and faucet aerators. Be prepared to flush them if the pressure seems low when the water comes back on.
The good news is that you can easily replace faucet aerators, clean showerheads to remove limescale, or simply buy new fixtures to replace the defective ones, which can improve your water pressure. However, it is important to know that repairing or replacing faucets and fixtures is only a temporary solution.
Open your main water valve.
Find the valve and check to see if it's completely open. Opening a half-shut valve is one of the quickest ways for increasing home water pressure. Sometimes the main valve is turned off accidentally during routine repairs and maintenance without the homeowner's knowledge.
In addition to the mains stop valve outside the home, you'll have one inside. Your internal stop valve is most likely beneath the kitchen sink. Your external stop valve is owned by the water company. If it's open yet the pressure here falls below one bar, it's their responsibility to improve it.
If the low water pressure seems restricted to a single faucet or showerhead, the problem isn't with your pipes or water supply, but with the fixture itself. If it's a sink, the most common causes are a clogged aerator or clogged cartridge.
Normal psi for a home pipe system is between 30 and 80 psi. While you don't want the psi to be too low, it violates code to be above 80. Instead, you should aim for a psi that's between 60 and 70.