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.
A fast drop in only one faucet means there's a problem with the faucet. Rapid low pressure affecting one area of the house may mean a corroded pipe issue. An abrupt water pressure drop affecting the whole house may mean a water main break (municipal water) or a well pump problem (well water).
Finding yourself running out of hot water more quickly than usual is often a sign that your water heater is on its last legs. When water heaters start to go bad, they often lose their ability to heat water properly, which can result in shorter showers and less hot water overall.
Your hot water heater has a shut off valve that can become partially closed. Good news about this issue is that it's a very simple fix—twist the valve back to its fully open position and your hot pressure should come roaring back.
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.
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.
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.
If it's only the hot water that is at a trickle, you might need a plumber to clean and flush your hot water unit. Sediment and scale in your hot water tank can build up as the tank ages and corrodes. This can cause blockages over time and low hot water pressure.
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.
Water Heater Valve: Each water heater has a shut off valve. If the shut off valve has been closed and not fully reopened, your home will experience decreased water pressure. Returning the water heater valve to “Open” status will increase water pressure and return your water pressure back to normal.
While today's water heaters are better designed than older models, they still require regular maintenance in order to prolong their lives. With regular inspection, draining, and flushing, you can expect a gas water heater to last anywhere from 8-12 years and an electric water heater to last anywhere from 10-15 years.
Water Heater Lifespan
A hot water heater's lifespan depends on many factors, including the type of water heater, the energy source, the type of water you have, and how well the unit is maintained. On average, most water heaters last between 8 and 12 years but some can last up to 20 years with regular maintenance.
With proper maintenance, a tank water heater tank should last six to 12 years. A tankless water heater can last for more than 20 years.
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.
Pressure-Reducing Valve
Look on the main supply pipe near your water meter for a conical valve that has a bolt sticking out of the cone. To raise pressure, turn the bolt clockwise after loosening its locknut.
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.
If your valves are open all the way and you're still experiencing slow water flow, then the cause might be a clog. The first place to check is the aerator. The aerator is the cap on your faucet where the water comes out of. It has a screen and, over time, sediment gets caught in it, which impedes water flow.
If you have a combi boiler or unvented system, you're unlikely to experience any issues with low water pressure. However, with a gravity fed system, you may run into problems if you don't buy a shower suitable for your water pressure.
Most homeowners should flush their water heaters every six months or so, but if you have extremely hard water, you may want to do it more often. Flushing your hot water heater could be necessary as often as every few months depending on the mineral content of your local water supply.
A professional can sometimes repair these issues, but if your water heater is older, you'll need replacement. For example, a 20-year-old water heater is nearing the end of its service life and will need to be replaced even if repairs are possible.
It would be wise to start looking for a replacement because, like all mechanical equipment, water heaters have a life expectancy. Traditional storage water heaters typically last about 10 to 15 years, while tankless water heaters can last 20 years or more.
Over time, sediment builds up at the bottom of the tank. When the water is heated, the sediments harden. As a result, you can hear banging or rumbling noises from inside the heater. This is a sign that you need to get a new hot water heater, as its nearing the end of its operational lifespan.
The short answer is yes, as long as you don't mind using cold water. Shutting off the input to your water heater will not affect your home's main water supply. You can still run appliances like your washing machine or dishwasher, flush your toilet, and use your shower, sink, or garden hose.
Advantages and Disadvantages
The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset their higher purchase price.