Dealing with a sudden drop in water pressure is no fun, especially when you have no idea what the cause is. Fortunately, zeroing in on the culprit isn't hard when you know what to look for. If you're worried that your water heater is to blame, here are some questions to ask that will let you know for sure and tell you what you need to do about the issue.
Is only one faucet affected?
If only one sink or tub is affected, your water heater isn't likely to blame. This could be as simple as a clogged aerator, so the first step is to remove the aerator (or the shower head) and soak it in a mild solution of vinegar and water. This should break apart any hard-water sediments that have accumulated.
If that doesn't solve the issue, you could have debris stuck in the faucet itself. Sediment can collect in the cartridges over time, and the washers inside the faucet can break apart and block water flow. If you're comfortable with DIY projects, you can try to fix the issue yourself. If not, this is something that can easily be addressed by a plumber.
Is the water pressure low in just your washing machine?
If your washing machine isn't filling up like it should, and the rest of the house doesn't seem to be affected, you're more than likely dealing with a blocked screen.
To address this problem, turn off the water behind the washer and then remove the hoses attached to the back of the machine. Look inside the intake where the hoses connect, and you should see a very small screen. Gently remove the screen with a pair of tweezers or a flathead screwdriver and either clean the debris or replace the screen altogether. This simple fix should get your water pressure back to where it needs to be.
Is only the hot water affected?
If the cold water is fine, but your hot water is lagging, the issue is almost always the water heater. One quick troubleshooting tip is to check the valve where the water enters the tank and make sure it's completely open. If it is, once again, sediment buildup is probably the culprit. As rust and calcium deposits accumulate in the tank, they eventually collect in the pipes, restricting the flow of hot water.
You can try to flush your water heater with a garden hose to get the sediment out. But if this doesn't improve the pressure, a plumber can let you know what needs to be done in order to get your water heater back in shape.
Is your entire house affected by low water pressure?
If every area in the home is affected, you could have one of several things going on. If you're a new owner and just moved in, you can check for a water pressure–reducing valve. These are installed by homeowners who want to reduce the force of water coming through the line. The valve is usually installed where the main line enters the home, so you may need assistance from a plumber in locating it. Also, it's best to consult with a professional before having the valve removed, as too much water pressure can damage your pipes.
If you don't have a reducing valve, you could be dealing with a leak somewhere from either the water heater or your main water supply. One of the best ways to find out is to do a visual inspection. Check your basement for any signs of water leaking. Next, walk around your yard and search for wet areas where the water supply meets the main line of your house. Also, check your water heater for puddles around the base or water dripping from one of the lines or drain valves.
If the leak is coming from the water heater, the tank might need to be flushed, or the fix could be as simple as repairing a pipe. If sediment buildup is really bad, the tank will need to be replaced. No matter where the leak is coming from, you'll need to get a professional to fix the problem.