Why Is My Hot Water Pressure Low? | The Plumber Explains All

[@TheJorgSacul]

I will try this when I get home tonight- my hot water pressure is just about useless. Cold is just fine. I just want to say, you are a National Treasure with your videos and advice. Thank you!

[@rebekaredmond6175]

Sounds like I might be having the same problem as you.

[@dawnjordan8444]

Thank you! I have this exact problem and have never understood what is wrong. This was very informative and helpful to me!

[@tnuttbutter]

Thank you! We’ve had lowering hot pressure for about 6 months. Was about to pull the trigger on a water heater replacement. Went and tried this, and the hot outlet was totally corroded shut. Whacked the build-up with a hammer and short flat blade a few times, and voila! Plug is gone, hot water pressure is back to normal! Woohoo!

[@josephviduya5679]

Thanks for the advice. My inlet valve was stuck. Just tapped it and all is well! Check your inlet valve. I believe this is present in fairly new tanks to conserve energy

[@marybroderick8265]

Whew! Another one of life's mysteries solved . You are a gem 😊Jim

[@kimberlythomas8366]

Thanks for that information, Sir. I just replaced the pressure regulator. That helped the cold side, so I was dumbfounded when the hot was still acting a fool. I'll try this immediately.☮️

[@ChuckP25.]

Thanks Jim. Great info. Thumbs up. Stay well.

[@SandraVoyles-zb5tf]

Thank you for all the tips . We women can do some of these things with your help and save some Money. Appreciate you and your son for doing this! God bless you both! 👍🏻

[@grthillbilly]

Jim’s knowledge fixed my problem. Thank You!

[@thomasborja3213]

Holy sh*t, this channel's a gold mine, i'm subscribing because I have a feeling I'm gonna be needing some of these videos soon

[@scottc6946]

Wanted to thank you for this, I had a huge blockage in the cold water inlet of the water heater. Just knocked it out with a hammer and screwdriver and good as new!

[@billy2bob63]

Thanks again guys good information!

[@Watsufun1]

Thank you, this was a different suggestion then what I was getting

[@mekachouh]

Work like a charm, thank you for the tip. One tip for you though ?, if you can be a little bit grumpier, that would be more fun!

[@patrickmccoy2205]

This Guy is great, saved me a lot of money, Thank you Sir!

[@dap777754]

Same problem here. Good cold pressure, half that on the hot side. So -replaced water hoses, replaced nipples, flushed tank (its spotless inside) after installing new ball valve flush, put in new expansion tank. Checked all faucets too. Problem persists. I've concluded my house is plumbed that way and I'll just have to live with it.

[@TheGrumpyPlumber]

Did you replace the shutoff valve on the cold side going into the heater? Are there any mixing valves installed near the water heater? These valves are called tempering valves so you can’t get scalding water on the hot side. If you have these, remove them. Now, how about the hot water pipe size? If you have 1/2” water piping for the hot, that would cause low volume but not low pressure. Does this only happen when you’re using the shower or tub? If so, replace the cartridges in the shower valves. Make sure there is not a shutoff valve located somewhere on the hot supply side that is not open all the way, or won’t open all the way. Hopefully there is not a globe valve on the hot water supply side. We haven’t used those in years, but just checking. If you have a water softener, are you only softening the hot water? If you do, the water softener might be the problem. These are the things I would be checking for if I was at your house.

[@dap777754]

@@TheGrumpyPlumber Good ideas, I'll have to check your suggestions out. All faucets in the house (20 years old) are the same - lower hot water volume than cold. No water softener; no mixing valves (I Think). It never occurred to me to fool with the shut off valve on the cold-water side (adjacent to my expansion tank), but come to think of it that valve was leaky and caused me headaches when I was trying to re-solder the water hoses back on. Don't fully understand why the cold-water side valve condition would decrease the hot water volume? But no matter, I'll start planning to replace that valve too. Thanks.

[@TheGrumpyPlumber]

Replace with a full port ball valve. The easiest way to do this, if you can, is to use a shark bite ball valve.

[@dap777754]

@@TheGrumpyPlumber Hey thanks again. I've already replaced cold inlet with a Watters ball valve, solder to solder. But no luck, the volume differential (hot poor, cold great) continues). Ideas?

[@TheGrumpyPlumber]

Has this been a problem since you moved into the house? Is there a 3/4” hot water supply in the house? Do you have water flexes on the heater? If so, turn water off to heater, disconnect the hot water and run the supply line into a bucket. See how much water volume you have coming into the bucket. If it’s good, then it probably has something to do with the size of the water piping on the hot side. They might have reduced the hot water supply side to 1/2”. This should tell you if there is a problem with the heater or the pipe size. Hopefully, we can figure out this problem together.

[@willyburd]

Very interesting.. I would've never thought of that. Thanks Pops

[@glennbrown9178]

Love the sharing of wisdom and experience.

[@nelson4592]

I recently had very low water pressure in our house. I watched your video and almost tore into our water heater. But, prior to that I looked at our water softener. I called the company and it turned out the minerals in the tank were very low. Replaced the tank and water pressure shot back up.

[@GeorgeLimon-t2g]

Thanks guys , madw it fast and to thepoint... Wife wven understood

[@Joizefnf]

Thank you for this video.. My problem is an odd one. The hot water pressure is low in the basement slop sink as well as the kitchen sink, first floor. The bathroom is on the second floor and has no issue with hot water pressure, both in the tub and sink. Tried moving the valve back and forth on the outlet from the water heater and even tapped it several time in hopes to dislodge anything that may be there but still nothing better. Do you have a video of the repair you speak of in this video? Thank you and any help would be great. :-)

[@TheGrumpyPlumber]

I don’t think you’re having a problem with the inlet and outlet on the water heater. I recommend you check to see if the angle stops are wide open on the kitchen sink and slop sink in the basement. Check to make sure there aren’t any kinks in the hot supply lines to the kitchen sink faucet and slop sink faucet.

[@chrishodde]

Thanks Jim!

[@TOTLE929]

hey pops this is the same problem i have.. but this only occurred after my contractor shut off my water line because he's renovating my kitchen. plus my water heater is pretty much "brand new" installed in Jan 2023.. i also have external water tank attached to my water heater but i guess that's only critical for over flow pressure coming from the heater coz right now pressure from my water heater is my main problem. Thanks.

[@pj8964]

Why are you so nice Mr. G P ... Thanks for the video ☺👍👍👍

[@samibehrend]

I have an AO gas water heater 6 years old. The pilot light goes out I have to reset the start it up by pushing button at least every other day

[@TheGrumpyPlumber]

It sounds like you need a new thermocouple. I recommend you call AO Smith, give them date of purchase and they should give you a brand new burner assembly.

[@brittblanton8342]

Hey Jim thanks for the great advice 👍

[@patloyarealestate]

Had a new water heater installed about 1 year ago. Since the new water heater installed our hot water does not come out as quick as it did with the old water heater. We do have a recirculating pump. I discovered not many plumbers at least in California understand the recirculating pump. So far I had one plumber come out to check it I was told we need a compression valve and angel valve cost is $850.00. My question is why did the recirculating pump work fine prior to the new water heater installation?

[@TheGrumpyPlumber]

@@patloyarealestate when they reinstalled the circulating line, did they connect it on the drain to the bottom of the water heater? Did they put a drain valve either before or after the pump so that you can bleed the air out of the circulating line? Did they put the pump in the right direction? There is an arrow on the pump and it needs to be pointing towards the water heater. I’ve been in this business for 50 years and I’ve never heard of an angel valve. It sound like that plumber was working for the devil and wanted to get into your wallet. A recirculating pump is one of the most popular devices installed on water heaters in large homes in California. Call a company that has licensed plumbers and not drain cleaners.

[@patloyarealestate]

@@TheGrumpyPlumber thanks for answering my question. I'm not sure to any of the questions you asked.

[@patloyarealestate]

@@TheGrumpyPlumber what would the hook up look like?

[@wildweaselkeeper]

I have a similar problem but it is only on the kitchen sink. When the water is cold, I have great pressure, as soon as I move it to hot, the pressure slowly drops to practically nothing which took about 1 minute to happen. I replumbed the whole house with copper because there were so many points on the galvanized about to fail, I did replace the dielectric unions on the tank, and made sure the pipes going into the tank were cleared. This helped a bit but the kitchen sink is still acting up, however, the pressure at the utility sink would make a firefighter envious. I replaced the aerator on the kitchen sink and the only thing I have left to replace is the cartridge at the sink, but I did take it apart and it looked pretty good to me. So my question is, why would the hot water pressure diminish to nothing at such a slow rate at only one service point? Is it a bad cartridge?

[@TheGrumpyPlumber]

It could be a bad cartridge. When you pull the cartridge back out, put a cup over the opening where the cartridge was removed. Turn the hot water on and see if you have a good flow of water. If you don’t have a good flow, replace the supply line going to the faucet. While you have the supply line off, use a piece of solder or something about an 1/8” in diameter and put it up through the supply line that is on the faucet. If you have the long supplies that come with the faucet, try to clean that out with something. I’ve done this several times with kitchen and lav faucets but if you don’t want to try these ideas, just buy a new faucet. I think that when you take off the cartridge and turn on the water, the debris should clean out.

[@mandi-xoxo]

I have a question that hopefully can be answered. Every once in awhile (maybe once every 2 to 3 months) ill turn on the hot water, great flow but then suddenly drops to almost nothing. If i keep the hot water tap open it will correct itself within seconds (maybe 2 to 4 seconds) along with a clunk kind of noise and then goes back to normal. It does this in all taps when it happens. Not just one tap but all. Cold water pressure never does this. Like i said this only happens once in awhile so im dumbfounded as to what this could be because it always corrects itself. I also have lower pressure when something else is running like a washer or someones in the shower. Its not horrible. I also have water hammers (singular noise. Im not sure if those are connected in some way. Anyways i hope u have an answer for me. Your time is very much appreciated.

[@justinpiety4657]

I changed the water out hose on my water heater now I have no water pressure cold or hot. All I did was change the flex hose, what could be the problem?

[@Masonm-s4h]

Do I need to drain the tank after cutting off the cold supply line? Or is it necessary to release the pressure before removing the inlet and outlet lines?

[@TheGrumpyPlumber]

Turn the water supply off and release the pressure from a hot water faucet. Do not drain the tank.

[@francescajamesacunaadams1131]

Thank you!!!

[@ScienceisRadAF]

My low hot water pressure issue started when someone shut the water off at the street for a maintenance. Once they turned it back on, our water behaved exactly as you said.. decent pressure when we first turn it on, then quickly reduces to maybe 20%. Same fix?

[@TheGrumpyPlumber]

Check the inlet and outlet water supplies on the water heater to make sure they are not blocked.

[@kesplit]

We have 1/2 inch pex in our house, so the water pressure is unimpressive. It's well water and the hot water has black specks in it...any idea what those specks are from? Water in and out of hot water tank is hooked up with a copper line, not flex lines.

[@TheGrumpyPlumber]

The specks are probably coming from the deterioration of the anode rod in the water heater. Turn power off to heater, drain and back flush until water comes out clear. You might want to replace the drain valve with a 3/4” full port ball valve.

[@a25b1]

would this apply to turning water supply on and off at the street? I replaced shut off valve at the outside outlet and good cold water pressure but dissipating pressure on hot side

[@TheGrumpyPlumber]

Check the inlet and outlet at the top of the water heater. Also, make sure the valves are open all the way. When you turn on the hot water, do you notice a lot of pressure and then it quits? That will tell you if it’s a problem at the inlet or outlet of the heater or a valve that is not completely open.

[@dustinkumar8289]

Would this still be the case if the low pressure from the hot side started after the removal of the water heater and installation of a new Rheem hybrid?

[@TheGrumpyPlumber]

When you open up a hot water faucet and have good pressure and then it slows down,there is a problem with a supply line or a valve. Does the Rheem heater have a leak defense valve on the cold supply side? Sometimes they don’t open all the way. Did they install new unions or supply lines? Always check to see if there is a gate valve or a ball valve that is not open all the way. Older valves can break when you open and close them. To answer your question, no, the pressure should not have changed when the new heater was installed.

[@jodiek70]

Hey, I just replaced my old water heater with a Rheem and this is exactly what is happening to me. Did you ever find the problem? I have zero plumbing experience so I have a hard time understanding what all the parts are that I should be checking.

[@cherferfm3770]

But what about if it is only the bathtub hot water that has low pressure? How can you fix that?

[@TheGrumpyPlumber]

Check and see if there are valves on the hot and cold inlets that are open all the way. Check to make sure the shower head has no debris in it. Check to see if there is an aerator on the tub spout. If there is, take it off and soak in vinegar or replace the tub spout with one that doesn’t have an aerator. If you have a single handle tub/shower valve, replace the cartridge with a new one. While you have the cartridge out, turn the water back on and flush before installing new cartridge.

[@ilikethetruth]

Our hot water is heated through our furnace.. so we dont have a " hot water heater like most people ' and we do not have hot water pressure since i moved in this house, its a skinny small stream.. but the cold is so strong and blasts out

[@TheGrumpyPlumber]

The furnace is heating the water but does the water then go to a storage tank until you need hot water? Check the inlet and outlet water lines at the storage tank to make sure they are not blocked.

[@jameshorton7496]

My problem is similar. I have pretty good hot water pressure in the summer, but when cold weather hits, hot water pressure goes down.

[@TheGrumpyPlumber]

James, are you on a municipal system? If so, check with the water department. You have a strange deal here. You might want to invest in a good pressure gauge and adapt it to the hose thread on the water heater drain. Keep an eye on the pressure.

[@dillonwilson-vv6ci]

​@@TheGrumpyPlumber Hi do you have an email that I can send you a video of the problem my friend is having with his plumbing? I'd type it out but it would be a lot easier to let you see whats going on in a video rather than trying to explain it in writing.

[@TheGrumpyPlumber]

Dillon, email is [e-mail]. Send that video the sooner the better.

[@davidsallee3867]

What if I'm having similar issues with water pressure but I have a boiler that heats my water?

[@TheGrumpyPlumber]

You have 12 lbs. of pressure on the boiler that has nothing to do with the domestic water pressure, even though the boiler is heating the water. If the water pressure is low on your domestic water, you have problem with the storage tank which is restricting the flow. Check the inlet and outlet connections on the storage tank to make sure they are not blocked.

[@bruce2104]

Great thanks

[@ricardovergara4521]

I just installed a new water heater but the problem I got is that I got no hot water coming out but the water heater is hot any tips are welcome

[@TheGrumpyPlumber]

Is your heater gas or electric? If electric, did you turn on the water too quickly before it was completely filled, causing the upper element to burn out? You’re telling me that you are not getting any hot water to any of your fixtures but you are getting water flow to the fixtures? Correct? You might have a cross connection somewhere like a valve at a bathtub that is a three valve diverter that is open.otherwise, I need more information.

[@Tammy-e4k]

Will this happen to the cold water too

[@TheGrumpyPlumber]

On the cold water pressure, you either have a bad pressure regulator or a valve that might be partially closed. A water softener that is not working right could cause low water pressure. A way to test that is to bypass the water softener. Check these ideas out.

[@MarcellusWashingtonII]

What if the inlet and outlet are copper pipes soldered to the water heater?

[@TheGrumpyPlumber]

If it’s an electric water heater, you’ll probably have to cut them off to check it out. Here is a suggestion: cut the inlet and outlet pipes about 12-15” above the heater. Use a tubing cutter to cut them. Sand them, install two shark bite male adaptors on the copper pipe ( make sure you buy the ones for copper). Remove the old connections to the water heater. Buy two 3/4”x24” water flexes. Reconnect to the heater. You probably have electrolysis on the inlet and outlet feeds on top of the water heater.

[@MarcellusWashingtonII]

@TheGrumpyPlumber Thank you for taking time to reply!

[@MarcellusWashingtonII]

Your solution did the trick! Thank you so much!

[@MarcellusWashingtonII]

About 48 hours into the fix, the issue has returned. Now, there is far less pressure than before the good fix. The hot water is now trickling out every faucet. Any suggestions?

[@TheGrumpyPlumber]

Remove the flexes and check to see if they are clear. Also check the inlet and outlet on top of the water heater. Go through and check to see if the aerators on the faucets are plugged.

[@khinmaug9886]

How to fix it?

[@daveknowshow]

new water heater new lines pressure in and flow rate in is very high. pressure and flow out at the water heater is next to nothing. what is the issue? ao smith says its not a bad water heater and will not issue a rma to return it.

[@TheGrumpyPlumber]

You need to check the inlet and outlet lines to see if they are blocked. Check the shut off valve to the water heater and make sure that is open all the way. If it’s a gate valve, sometimes the stem might be broke. If there is low flow on the hot water only throughout the house, it’s got to be some problem at the water heater.

[@daveknowshow]

@@TheGrumpyPlumber yup it was the out going heat trap located in the hot out nipple. I ran a 1/2 inch drill bit down it and now she slings water out there like a fire hose!

[@Mr.MarkWilliams]

So my is doing exactly that. So I cut off my water that’s coming into my hot water tank, then take off both of my lines that run to the top of my hot water tank. There are two what I question you call the nipples. Take something to check to see if any side is clogged up. Try to clean one or both of the openings of the nipple? Am I right. I hope this help. Thank you

[@daveknowshow]

@@Mr.MarkWilliams mine was a faulty nipple heat device. I drilled it out and now she. Flows great!

[@joserobertoportillo9179]

Bello esto. Papa e hijo

[@SamFisher300]

My main waterline from the street to my hot water tank is probably about 80-85 feet my house sits off the street it’s ok water pressure is there anything I can add to my main water line before hot water tank to add pressure

[@TheGrumpyPlumber]

Wayne, you can add a buster pump but it would be cheaper to run a new water main and increase the size. You might check with the city and see if they would be able to increase the pressure. You can remove the water saver plugs in the shower heads and see if that helps.

[@chattymatt]

I think my natural gas water heater is producing air that is getting into my hot water line and causing it to spit a bit when I first turn on the hot faucets in my house. This only started happening recently. I found some people saying it might be extra corrosion happening and maybe I need to do something with the anode rod thing. I cant figure out if I should remove it and put in a plug, or replace it. Anyone have any ideas?

[@TheTimmir]

Your amazing, thank you

[@victorpayne6586]

New hot water heater 2 yrs ago and have low hot water pressure? What should I do?

[@TheGrumpyPlumber]

Victor, check the inlet supply and outlet supply lines to see if they are blocked. Sometimes you can get an electrolysis reaction from the pipes causing them to rust shut. If that is the problem, take the supply lines off, take a hammer and screwdriver and knock the rust out of the pipe nipples and supply lines.

[@Mr.MarkWilliams]

And how will I know if there is rust in the line

[@cinefan21]

I work for a plumbing company. We have components of the heat trap nipples cease up. We just remove them and put in brass nipples. A little more advanced of a job especially if the nipples are in poor condition.

[@TheGrumpyPlumber]

Are you talking about di-electric unions? They are supposed to stop electrolysis but they don’t. I haven’t seen heat traps on a water supply in about 50 years.

[@cinefan21]

@@TheGrumpyPlumber I don’t believe they’re di-electric unions. The nipples have what look like small fishing bobbers in each of them that only allow flow in one direction. When they cease up is when pressure loss occurs.

[@b234543]

but this only happens in my guest bathroom the main bathroom and the rest is fine. its been bugging me for a while but have over looked it because its the guest bathroom and mainly in the shower which doesnt really get used

[@TheGrumpyPlumber]

Can you remove the shower head in the guest bathroom and see if it’s clogged? While you have the shower head off, turn the valve on and see if you have a good flow of water out of the shower arm. If you have a good flow, replace the shower head if you can’t clean it. If not these two things, you will need to have the shower valve repaired. You shouldn’t have to replace it.

[@khinmaug9886]

I water not hot the whole house?

[@mannypakyaw3773]

TALK TALK TALK!!!

[@AddValue777]

THANK YOU! YOU SAVED ME ABOUT $1,500 TODAY!

[@ACoustaDC]

Your advice seems sound, let me run it by the parking meter maid for verification though! Have a great week Jim..

[@TheGrumpyPlumber]

ACoustaDC, I’m sure she will verify that! Always great to hear from you!

[@mikev.1034]

👍🤙🤘😁

[@dustbat]

Why does my new hot water heater smell like rotten eggs on the hot side?🦇

[@TheGrumpyPlumber]

I would suggest removing the rod and see if the smells goes away. Turn the water heater off, release the pressure by opening a hot water faucet, use a 1 1/8” socket with a long breaker bar to remove the anode rod. In the opening, put a 3/4” galvanized or brass pipe plug. Turn the gas valve down to pilot, drain the heater completely then reheat the water. Wait a couple of days to see if the smell is gone. If the smell is gone, either leave the rod out or replace with an aluminum rod. Hopefully, that’s the problem.

[@dustbat]

@@TheGrumpyPlumber Thanks for the speedy answer.🦇

[@tjcrash473]

You guys are awesome, I have a question for you guys. I'm in Ohio and just repaired a galvanized line in my crawlspace and now no pressure anymore. Unfortunately I think all the crap inside the pipe went through the whole house. Please help me Sir 🙏

[@TheGrumpyPlumber]

Take a supply line and hook it to your angle stop and flush it out. See if that might help. You might have to change your supply lines. Whenever you turn off your water with galvanized or copper water lines, you want to turn it back on very slowly. Hopefully, you can clear the rust.

[@tjcrash473]

@@TheGrumpyPlumber Thank you Sir I really appreciate it! 🙏✝️♥️

[@bruce2104]

Great thanks