Summarize the following:
If only your hot water taps have low pressure, look for a problem at your water heater. Here are the most common problems:  Sediment clogging the water heater or the hot water supply line. flush the tank, then hire a plumber if that doesn't work. To prevent this happening again, replace the anode rod regularly and consider Installing a water softener. Hot water supply pipes that are too small. In most cases the pipe leading from your water heater should have at least a ¾" (19mm) diameter. Leaks in the valves or the tank itself. Only attempt to repair these yourself if the leak is minor and you have experience with plumbing projects. Leaks are a common cause of low pressure. Conduct a quick check for damp spots beneath pipes, especially at the main supply line. Fix any leaky pipes you encounter.  Small damp spots may be caused by condensation. Put down a couple paper towels and come back the next day to see if they are wet. If they are, you have a problem. A leaky toilet mechanism fails to block the flow from the tank to the bowl. Put a few drops of food coloring in the tank, and come back after an hour or two without flushing the toilet. If the food coloring has entered the bowl, your toilet needs a repair. Typically, all it needs is a new flapper or another cheap and easy fix. If you can hear your toilet running constantly, that's definitely a drain on your pressure. Learn how to fix it. If you still haven't found any leaks, it's time to check your water meter to confirm or deny their existence. Shut off all water in the house, then read the meter. There are two ways to check for leaks using the meter:  If the small triangular or disk-shaped dial on the meter is spinning, water is still flowing. Assuming everything is shut off properly, you have a leak. Write down the reading, wait a couple hours without using any water, then check again. If you get a different reading, you have a leak. Look for the master shutoff valve near your water meter. If it's been knocked to a partially closed position, turn it back to fully open. This is rarely the problem, but it only takes a few minutes to test. Homes on low ground often have a PRV installed where the line enters the building. This valve, usually shaped like a bell, reduces the supply of water to a safe pressure for your building. On a typical model, you can turn the screw or knob at the top of the PRV clockwise to increase water pressure. It's best to turn this only a couple times, keeping track of the number of turns. Going too far can damage your plumbing.  If adjusting the PRV doesn't make any difference, shut off the water supply and disassemble the valve. You may need to replace a part or the entire valve, or just clean the parts. Finding manufacturer instructions is recommended. Not all homes have a PRV, especially if the city water supply is low pressure or the building is on high ground. If your home has a water softener installed, try setting it to "bypass." If the pressure improves, have someone inspect your softener for issues.
Address problems with hot water supply. Check for leaky pipes. Test your toilet for leaks. Check the water meter to rule out leaks. Confirm the shut off valve is completely open. Inspect the Pressure Reducing Valve. Test your water softener.