Low Hot Water Pressure
Hot water heater pressure help
Low hot water pressure is usually caused by sediment, rust, calcium deposits or other debris in the plumbing lines or faucets. This often occurs after the plumbing has been worked on, water heater replaced etc.
Sometimes the pressure will slowly decrease over a period of time, particularly if your home has been plumbed with galvanized pipe.
If you have just moved into a house with low hot water pressure take a look at the plumbing going into and out of the water heater. If it has been plumbed with 1/2 in. pipe going in or coming out you will not get as much pressure as you could if it were plumbed properly.
Corrosion and rust will slowly clog galvanized pipe. There's not much you can do about this except replace the pipe, however it is worthwhile to check your aerators and faucets. Just follow the guide below.
Low hot water pressure in part of the house
A clogged aerator is the most likely cause of low hot water pressure in a sink faucet.
Remove the aerator with a pair of
pliers (see pic).
Now check the hot water pressure. If cleaning the aerator didn't help go to the next step.
You may have a clog in the faucet itself. This is an easy fix.
Turn the hot water off under the sink.
Use a knife to pry up the ID button
on the hot side faucet handle.
Unscrew the stem retainer nut and pull straight up on the stem, it should pop out.
The stem may have a washer mounted on the bottom of it. If not there will be a washer and spring inside the faucet housing.
Gently remove the washer and spring with a small screwdriver.
While holding a cup or glass over the
faucet turn the hot water supply on
and off several times.
If you still have low hot water pressure the
problem may be the supply line under
Single handle faucet
Turn both the hot and cold water off under the sink.
Low hot water pressure in the bathtub and shower
If you have low hot water pressure in the shower only and
not in the tub remove the shower head with a pair of pliers.
If you have low pressure in the tub faucet it will disassemble
much the same way as the other faucets.
On a single handle faucet you'll find a screw on each side of the faucet body after the large chrome cover is removed. Screw both of these in tight before you remove the stem. If you can't see them (sometimes builders cover these up) you need to cut off the main water supply to the house.
When you have everything removed from the faucet turn the water
on and off several times to flush out all debris.
Low hot water pressure in the clothes washer
The water inlet valve on the back of your washing machine where the water hose is attached, has a screen to catch debris before it enters the machine.
Cut the water off behind the washer. Remove the hot side
hose. Carefully pry the screen out with a small screwdriver.
Clean the screen and reinstall.
Whole house low hot water pressure
To solve this problem we'll have to start at the water heater and
eliminate possible causes one at a time.
If you have older galvanized pipe or any 1/2 in. pipe entering or leaving the water heater you will not be able to get great hot water heater pressure.
Check water heater fill tube and shut-off valve
The water heater shut-off valve should be located on the cold water line near the water heater.
Check the valve to be sure it is opened all the way.
The next step is to see if you have the proper pressure going
in and coming out.
If your water heater is plumbed with copper or cpvc you'll have to cut the lines and remove the fittings from the water heater. If the plumbing is not attached to a nipple at the heater you will need to get a 3/4 in. nipple to screw into the water heater so you can attach a garden hose to it.
Turn off the water supply to the water heater. Grab your wife's
mop bucket and drain about 1/2 gal. of water out of the heater.
Remove the flex line from the hot side (where the hot water comes out of the water heater) of the water heater.
Take a flash light and look down the nipple where you took
the flex line off. If you see a lot of build-up in the nipple you've
found the problem.
If you don't see a problem at the nipple attach a garden hose
to the nipple and run the hose outside. Make sure its not kinked
If the pressure is good you have eliminated the water heater
as the source of the problem.
If the pressure is not good coming out of the water heater you'll need to check the pressure coming into the water heater. This will involve checking the cut-off valve and the water heater dip tube.
The cut-off valve or gate valve that controls the water supply to your water heater can malfunction and cause low hot water pressure
There are a couple of ways to check the gate valve. Choose the one that's easiest for you.
Shut the water off to your house, remove the top of the gate valve,check that its working properly and for any obstructions.
Detach the flex line on the cold water side. Screw a 3/4 in. nipple into the end and attach a garden hose to the nipple. Run the hose outside, turn the shut-off valve on and check the water pressure.
It's possible that the water heater fill tube has clogged. To check it, remove the water supply line on the cold side of the water heater. Remove the nipple if there is one.
The fill tube is a plastic pipe with a flange at one end to hold it in place. To remove it insert your finger into the pipe. Wiggle your finger to loosen it and pull it out.
You will see a small hole in the fill tube about 6 in. from the end. It's suppose to be there.
This is a fill tube that I removed from an old water heater behind my shop.
While you have the fill tube out of the water heater check it for cracks. Replace it if you find one.
If you have copper plumbing it can be a pain to cut it loose. You
can check your fill tube another way.
Other causes of low hot water pressure
If you have a water softener by pass it and check your pressure.
A water leak can cause loss of pressure. If your house is on a concrete slab walk around the house and look for a wet spot. Put your ear to the floor in the kitchen and bath. You may hear water spraying. This really works!
To eliminate future low hot water pressure problems. It's a good idea to flush your water heater every three months. flush hot water heater
Clean your water heater at least once a year. cleaning hot water heater
Return to water heater repair guide from low hot water pressure.