The Thermostat Is Too High If the hot water heater thermostat is set too high, pressure will build up in the tank. Any temperature greater than 120 degrees can cause damage to your hot water heater. When you adjust the thermostat to a safe level, the hot water heater can function optimally.
Checking the pressure gauge mounted on the side of your water heater can help prevent water tank failure. If it is too high, try lowering the thermostat and then check your expansion tank to make sure that it is working properly. A malfunctioning expansion tank can cause too much pressure in a hot water heater.
Temperature Fluctuations: The primary cause of excessive pressure in a hot water heater is fluctuating temperatures. If the thermostat is set too high, the water in the tank can overheat, leading to expansion and increased pressure.
Why Is My Water Pressure So High All of a Sudden? Sudden increases in water pressure can be alarming. A sudden increase can be due to a broken pressure regulator or a change in the municipal water supply. Additionally, temperature changes or a burst pipe could cause sudden spikes.
If your pressure is higher or lower, then you'll need to install, repair, or adjust your pressure regulator to comply. Adjusting your regulator is easy, as long as it's working properly. Simply tighten the screw down clockwise to increase pressure and counter-clockwise to decrease pressure.
It's normal for pressure to build up in your hot water tank. As water heats up inside your water heater, it goes through thermal expansion. Hot water takes up more space than cool water.
Bleed a radiator
As well as releasing air trapped in the system, bleeding can also be carried out to lower the water pressure. We've written an article on bleeding radiators here, but in summary, locate the bleed valve on a radiator, place a bucket or tub underneath or next to the valve, and open the valve gently.
This is a serious concern—water pressure that's too high is difficult to contain, and could leak to plumbing leaks, worn seals, and damaged fixtures. It could even shorten the lifespan of your appliances that depend on a water connection like your washing machine, ice maker, dishwasher, and more.
The regulator will have a screw or bolt and a locking nut system. Loosen the locking nut with a wrench and using quarter-turn increments, use a screwdriver to turn the screw counter-clockwise (to the left) to decrease water pressure, and clockwise (to the right) to increase water pressure.
The most common cause of this is if you have recently topped up (repressurised) your boiler after it's suffered from low pressure. How to check: Check the needle reading on your ever trusty boiler pressure gauge – if it's reading over 1.5 bar (when the boiler is switched off), your boiler pressure is too high.
Hammering or Vibrating Noises
Repetitive knocking or consistent humming noises that seem to come from the walls when you run different fixtures are often caused by a failed PRV.
By releasing some of the hot water and air, the valve lowers the pressure back down to safe levels. For reference, the normal pressure of the water inside of the water heater tank is 50-100 PSI.
A malfunctioning pressure regulator is one of the primary causes of too much pressure in your plumbing system. This device controls the flow and pressure of water entering your home. If it fails, the pressure can surge, leading to various plumbing issues.
This causes damage to essential water pipe joints, fixture heads, and valves. In addition to the failure of such fixtures, high water pressure can lead to pipes bursting when they cannot contain the water.
If you tighten the screw the water pressure will be more and if you loosen the screw the water pressure will be less. Turn the screw clockwise to tighten it and increase the pressure, or turn it counterclockwise to decrease the pressure. Do not be too hasty.
The most common cause of high pressure in a hot water heater is the excessive buildup of steam or air within the tank. This can happen when the heat exchanger inside the tank becomes blocked with sediment or mineral deposits, preventing the heated water from properly releasing steam or air.
For most units, open the water pressure relief valve by simply lifting the valve up until the attached brass stem rises. When you do this, hot water will rush out of the pipe near the bottom of the water tank. Then, push the lever back down to close the valve and stop the water flow.
If you're dealing with ongoing high water pressure, you should check on your regulator. You may be able to lower your water pressure by adjusting the regulator, or you might need to replace it with a new one.
Traditional tank water heaters also suffer from sediment build-up. In this case, you clear the sediment by emptying the water into a bucket or down a drain until it runs clear. Clearing the sediment often restores your water pressure to its maximum potential.
Broken Thermostat
When your water temperature seems exceptionally high, check the thermostat right away, before you pick up the phone to call a plumber. Although most water heater thermostats are set at 60 degrees Celsius (140 Fahrenheit) when first installed, the recommended setting is 49 degrees C (120 F).