lack hot water pressure in the entire house

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by cindyz, Sep 25, 2004.

  1. cindyz

    cindyz New Member

    the hot water pressure on 2nd floor is very weak since 4 weeks ago. Anyone
    use hot water with any faucet, the rest of faucets has no hot water. I called
    several plumbers to take a look. None of them gave me a sure answer. Some
    say the water heater is old (10 year old), they suggested me to change the
    heater, see if fix the problem. Is anybody here had the same problem before?

    Thanks in advance!

  2. jimbo

    jimbo Plumber

    San Diego
    Well, I don't like the idea of spending $750 on a water heater intall "to see if it fixes the problem". The problem could be clogged nipples at the inlet or outlet of the WH, or a clogged or partially closed shut-off valve on the WH inlet. It is true that a 10 year old WH may fail tomorrow, or it may have 5 good years left on it. I would not spend a lot of money fixing it, but the 2 items I mentioned could be checked or repaired for a reasonable amount, although there will be a minimum service call charge. Other that the 2 items mentioned, it is unlikely that the WH itself is the cause of low pressure.
  3. cindyz

    cindyz New Member


    Thanks a lot for your reply. I forgot to mention that one of the plumbers
    thought the valve ( there is a valve from the WH to the wall) may clogged. If the problem resolved by changing the valve, he will charge $250, if not he only charge $25 for the new valve. I think $250 is too high, even he resolves the problem.


  4. jimbo

    jimbo Plumber

    San Diego
    Difficult to compare prices from area to area. I know that if you are in NY City, that would be about right.

    Call one or two other plumbers. Tell them you want to replace the shut-off valve. I'm thinking if someone offered to do it for 1/2 of that, it would be reasonable. As I mentioned before, the valve itself is about $10 and the time to do it could be as little as 15 minutes, but you have to absorb a trip charge.....somebody has to pay for that plumber's time while he is driving to and from your house. And I can guarantee that the somebody is YOU. SO now, we are back to considering the possible life expectancy of that 10yr old WH and how much is reasonable to spend. Replacing the valve and nipples as part of a new WH install would be negligible expense. The part I didn't like was when the guy said "....see if it fixes the problem...." at a cost of $750. He may be a competent plumber and just didn't express himself clearly.
  5. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

    Wichita, Kansas
    Hot on First?

    You imply that you have good hot water on the first floor so the restriction would be after the floors split. If you have galvanized pipe then replacing a valve may not help. Nor would replacing the water heater. Ask another plumber to come look.
  6. Deb

    Deb Plumber


    Did anything else happen 4 weeks ago to coincide with the problem?
    Never trust a plumber (or anyone else for that matter) who, when they cannot find the cause for a problem, suggests replacing things to "see if it fixed the problem" (and expensive parts at that). That is absolutely ludicrious. There is a cause, and it is something that you should be able to figure out. Very, very seldom are we unable to discover the cause of a plumbing problem after investigation.
    What exactly did the other plumbers do? Did they disassemble a faucet? Did they check the condition of your water lines (what material are your water lines)? Did they offer any real possibilities (a clogged valve/nipple/union/etc at the water heater is not a REAL possibility because 1st floor would be affected, just to a slightly lesser degree)?
    I would start by pulling the hot faucet stem/cartridge/disc and check for debris. Hold your hand over the hole and have someone else slowly turn on the shut off to see if you have water to this point and flush the line if there is. If there is debris in the lav, there is probably debris in the tub/shower valve. If there is no water, I just start to work backward--check the riser, check the stop. If the problem is in the lines in the walls/floors, you can back flush to the water heater. There are several ways to do this, the easiest depends on your individual plumbing. Basically you want to shut the electricity/gas and water off to the water heater, hook a hose to the drain and run outside, open the drain and drain the water heater down some. You want to connect a cold water line to a hot water line and turn the cold on to force it backward through the hot lines and into the water heater, hopefully pushing any debris back the way it came and into the water heater. You can disconnect the lav risers and run a ss braided supply line from the hot stop under the lav to the cold stop, turn both on and backflush. This is generally the easiest. But, you can backflush through the tub/shower valve, if it is a non pressure balance valve. To do this, you need to plug or cap the shower head (remove the head and put a 1/2" cap on the threads) and/or the tub spout and turn both hot and cold on. The tub spout is harder to plug off, but you can generally hold a rag tightly to the spout and get it to flow back.
    Or, you could have old galvanized water lines that have internal buildup to the extent that the water supply is affected. There is really no repair for this, replacement is usually your only option. Age is not the major determinating factor in how long galvanized water lines will last, water quality is. I have seen galvanized that is 50 years old with virtually no buildup and 7 year old lines with less than the diameter of a pencil opening--water quality.
    If you don't feel comfortable checking these things out, call another plumber. See if you can find a family member, friend, co-worker who can recommend a plumber. A tradesman who does good work at one job most likely does good work (period) and vice versa. This got longer than I intended, but it fries me when people hire a plumber(s) who doesn't do diddley, offers no REAL possible solutions, and tries to sell you something you might not need because they do not know what is wrong :eek: So, I wanted to give you the best, most complete advise I could without being there. These are things that take average mechanical skills (except possibly disassembling the tub/shower valve if necessary) and do not take any expensive tools. You could need stem sockets, which are inexpensive.
    However, a competent plumber should most likely be able to check all the stuff I mentioned in an hour or so depending on your system--do shut off valves shut off? How accessible is everything? Condition of existing plumbing? Etc. Shame on those plumbers that (IMHO) didn't do their jobs and/or tried to sell you something that they should have known could not have fixed the problem (and if they are a real unscroupulous type who did this because you are a woman, I don't even begin to have enough bad words to say about them!). There's an answer. You just need to check out all the possibles (the list isn't that long) and when you find it, fix it. I frequently tell people that they pay me just as much or more for what I know as what I do. Many repairs that service plumbers make can be done by a person with average mechanical skills. The problem is that most of them do not know what the problem is and if they do, they do not know the fix. Frequently the fix is something simple, the diagnosis the tough part. A plumber that cannot figure out the possibilities and eliminate them one by one is not much of a plumber.
    Enjoy your day.
    The Pipewench
  7. TTM

    TTM New Member

    Chula Vista
    Similar Problem...

    I have a similar problem as Cindy, except that I have no hot water pressure at all (found this problem last night). It looks like no water is getting into the tank because I've tried draining it and only a few cups of water came out. My suspicion is that the valve is clogged or inoperative. I'm new here and I saw mention of nipples also. I tried to remove the valve last night but it seems to be fairly well locked in place. I put some solvent (WD-40) in it last night and maybe that will loosen it up a bit so I can remove it. The WH is the original with this house and is close to 16 years old. The last time I received an estimate to replace the WH the plumber gave me an estimate of $1700:eek:. I could really do without that expense at the moment. Hopefully I can replace the valve and that will be it but I'm wondering if this WH needs to be replaced and I should go looking for other plumbers here in the San Diego, CA area to see if there is a better price. Any ideas or suggestions are welcome. Thank you.

    Last edited: Feb 17, 2008
  8. TTM,
    I'm not a pro plumber, just a long-time DIYer (50+ years with more than 14,000 posts total on various DIY websites over the years), and Deb's reply to Cindy above is one the best I've ever seen.
    Hot water pressure out is usually directly related to the cold water pressure in, with the cold supply valve usually the culprit, if galvanized pipes aren't involved.
    What do you have?
  9. TTM

    TTM New Member

    Chula Vista
    All my pipes, as far as I can tell, are copper.
  10. dialectric nipples are clogged up

    Like MR JIMBO first stated ,,,,

    it is most likely at the out going line from the waterheater...
    90% chance its probably on the hot side....

    if the copper is tied directly into the water heater with copper male
    adaptors, simply cut the hot side of the copper 4 inches above the heater
    ....then get yourself a large screwdriver and probe down into theheater....

    you will hit a calcium deposit that has build up inside the copper pipe.... take that large screwdriver and a hammer
    and simply rheem and ram your way through that deposit....

    rheem out that obstructioin a few times and your problem will go away...
    for about another 3 years

    get yourself a brass compressioin fitting and put the pipe back together
    and see what happens....

    if that dont work , do the cold side.
    Last edited: Feb 17, 2008
  11. TTM

    TTM New Member

    Chula Vista

    Thanks for the suggestions all....I have visitors this weekend so I'm waiting for them all to use the restroom and/or cold showers before I get back to the problem. I also called a co-worker of mine who used to be a plumbers assistant back in Michigan when he was going to college to help me out. I'll let you know how it goes.

  12. Herk

    Herk Plumber

    S.E. Idaho
    There are a number of things that can cause a problem like this.

    1. a check ball, either in a heat trap or dip tube, can be stuck with some debris or sediment.

    2. Calcium deposits could have closed off the opening on the hot side of the heater.

    3. Overheating could have melted something.

    The valve may be defective.

    I don't know how the pipes are attached to your heater. Here, most are hooked with copper water flexes. I would take a flex and attach it from the cold line to the hot line and see if the water then flows normally. if it does, that eliminates the valve and the hot water lines.

    Then, I'd check the outlet of the heater to see if it's closed up with something.

    Then, I'd pull the dip tube.

    If there are dielectric nipples, I'd pull them off and replace them with new ones if necessary. It's often hard to remove them without damage.

    There are a lot of variables: sometimes, the dielectric nipples are hooked to an anode rod or the dip tube is part of one of them. These are things you find out as you go along.

    If you can afford it, this may be a good opportunity to replace the water heater anyway, since they do have a relatively short life, most of which is probably used up in ten years.

    Never put WD-40 in plumbing where there may be rubber parts such as O-rings or packings or washers as it is a dissolvent.
  13. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Central Florida
    If only a few cups of water come out, it may be because of accumulated debris in the bottom of the WH is blocking the valve. Try draining with the cold water supply turned on, to see if the supply pressure will help flush the valve.

    As a possible hint as to what you might be facing, I recently replaced a WH of unknown age (but well over 10 years) which exhibited the same symptoms. Out of curiosity, I cut the old one open to see what was inside. I can only say that a) it was a good thing my wife didn't see it, and b) it was about 9" deep.

    I wouldn't spend a nickel on a 16-year-old WH.
  14. misterZ

    misterZ Engineer

    Northern Virginia
    Shortage of Hot Water pressure and flow in house

    I was suffering from low pressure and flow in house HW system on ALL floors of the house. I have a direct gas fired HW Rheem 41V50 HW tank, about 10years old. I figured it is getting a bit old, but just can't spend the money to replace it yet if I can help it. I found this thread after much internet search and pleased to report that herk and also master plumber mark's comments about 90% chance calcium blockage exists on hot water exit port of hot water tank to be 100% correct! The rest is the story ...
    I drained the HW tank completely, then bypassed the cold feed directly into the hot supply into the the house with a flexible pipe, the kind used to couple HW tanks to the house. I bought it and the coupling from Home depot for about $18 total. This completely bypassed the HW tank feeding cold into the "hot" pipes of the house. I confirmed that the house plumbing was AOK by checking the pressure and flow out of all the house taps - hot and cold in the house and comparing hot to cold flow/pressure. Of course only cold came out of the "hot", but I could see that for one sink with just the "hot" turned full on, it took 1min15sec for it to fill up the sink and it increased to 1min 20sec with all the "hot" AND cold taps in the rest of the house turned on. Before, if I did this, if I had just four "hot" taps on, it would take four times longer! It was pathetic.
    So I could see the problem was definitely in the HW tank. So herk and master plumber mark's advice came into play then. I wasn't brave enough to hacksaw or use compression fittings - but luckily I could unscrew the copper pipes from the HW tank leading to the plastic piping leading further into the house hot water pipes. It was a straight shot down this copper pipe, and I could shine a flashlight (!) down the 3/4" diameter, 36" long pipe. WELL I WAS AMAZED. I really didn't see an opening at all! I found a brass rod about 1/8" diameter about 48" long, and tried to push it down there through what should have been a hole or something. It wouldn't go down! I marked on the rod where it stopped relative to the copper pipe - it was dead on at the point where it exits the top of the HW tank - to the nearest 1/8" from what I could tell. I imagine water did somehow get through it - must have been porous or something. So I started ramming and reaming it out best I could (very long story - about 2hours worth). In the end, the stuff that came out was like grey sand/putty - it was very dense and very hard and gritty, like a grey calcium buildup(?). Well I finally got a hole through with about 1/2" diameter where there was no hole before. I was exhausted! So I hooked up all the pipes again like before, but I turned off the valve into the HW tank so no cold could go in, but turned on the house water supply. It turns out that some cold water backflows down the hot supply in reverse if there is no pressure behind it to stop it. (must be mixer taps?). I didn't expect this, but thought this is good to prevent all the junk from being flushed through the HW system! Well this helped to flush the scapings and junk that I reamed out down INTO the tank, which I then drained out from the draining spigot at the bottom of the HW tank. It sure was black stuff. This took quite a long time. Finally, I turned the cold supply on to the HW tank, and kept the burner off (Direct fired tank) and turned on all the hot taps in the house. After all the spluttering and coughing from the taps, finally water (albeit cold) came very forcefully out with the pressure and flow identical to my bypassing experiment earlier. So flow was cured. It flushed the tank for about another hour until it finally ran perfectly clear again without any sand or grit forming at the bottom of the bathtub at the highest point in the house. Then kicked in the burner to make it hot. It all works very well now. I'm sure I will need a new HW tank soon - 10years is a good run, but at least I can put off the $700 to $800 for a new tank for maybe another year or so. Thanks to all the contributors on this thread, and to herk and master plumber mark for their guidance and to the point explanations. (unlike this reply!).
    Last edited: Dec 3, 2008
  15. kingsotall

    kingsotall Plunger/TurdPuncher

    And, you misterz, are awesome... :cool:
  16. you were lucky

  17. sloaninnovations

    sloaninnovations Sloan Valve

    Got my hot water running again doing the following:

    1. Turn off cold water flowing into top of the hot water heater
    2. Drain some of the water out of the bottom of the hot water heater, not too much (you might want to run a hose depending upon where your heater is located)
    3. Open and run a house faucet to remove hot water from lines, then shut off
    4. Turn cold water back on at the top of the water heater

    This basically was breaking free some of the debris at the point of entry for the cold water.
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