Announcement

Announcement Module
Collapse
No announcement yet.

What did I miss

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • What did I miss

    8 year old State water heater, electric. Running out of hot water quicker. Coincides with turndown of outside temps.

    Ck'd connection up top, good, tested good

    Replaced thermostats with robertshaw brand, same result, told customer to order OEM upper/lower thermostats to rule out retrofit possiblity of not correcting problem

    Customer called, company shipped elements instead of thermostats ???

    Told him to call me when the thermostats come in


    Called, I go and install thermostats, next day same situation hot water runs out

    Told him I'll go ahead and replace elements now, even though I did a continuity test on both of those elements and BOTH showed continuity with the wires removed

    Replace both elements last night, called customer same result


    This heater has new thermostats and elements, I never replace one thermostat when one of the two is defective because it's senseless to do one when you know that the other could've been affected by the failure.


    The customer stated the water was extremely hot before it malfunctioned.

    This heater ran in operation from the day it was installed up till two weeks ago with no error. I've obviously looked over something that is keeping this heater from operating properly.

    When I removed the lower element last night, couldn't get continuity on the lower element, I did the first time I tested it.


    Anyone think that the dip tube might of melted/broke off due to extreme water temp? A dip tube that is partially broke off/gone can instantly cause the symptom this guy is having.

    Guy was paying cash, he's close by, normally I won't bother giving these old heaters a work-through knowing that it's a matter of "how long will it last" after you've spent nearly $200+ dollars doing repairs not knowing if it'll leak or not.

    I told the guy I'd like to have a second set of eyes on it to see if I've missed the boat completely on this one.

    I'll pull a favor with another plumber that owes me and see what he comes up with but would like to see if anyone has a possible reason why I didn't correctly diagnose the problem.

    Any chance a wire separated in the jacket when it malfunctioned? I'm not ejumakated enough to do a sequential testing on the wiring schematics to know what wires to test off. I do the blanket trick (like I said, rarely do I work on older heaters) knowing the new product is a better risk/investment for the customer.

    Any and all thoughts appreciated. Guy wants me to install a new heater to rid the problem....he knows he's in the window for when they go bad anyway. Tried to buy a new breaker just as a last resort and of course, it's a no-name brand. It's getting juice to the heater but who's to say that couldn't be the problem either....
    Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

  • #2
    Re: What did I miss

    Usually having a good understanding of how something works can help alot. If I am not mistaken, here is the way an electric hot water heater works. The cold water feeds into the bottom of the tank. There is a pipe that connects to the cold water inlet that feeds water in to the bottom of the tank and the hot water comes out from the top. The lower element turns on and starts heating the water, when the lower part of the tank reaches temp, then the upper element is turned on and the lower element turns off. I am I correct, both elements do not run at the same time, they alternate. Lets assume the pipe is broken off that feeds the water to the bottom of the tank, when the hot water is NOT being used, all the water in the tank will get hot. When you start drawing hot water,, the water will be hot for a little while and as the cold water comes in to the top of the tank because the pipe that feeds the cold water to the bottom is broke off will then contaminate the hot water at the top of the tank and cool it down right away. If everything is working correctly as it should since you replaced everything, then the likelyhood of what I say could be very possible. When you get to the bottom of this let us know. Lou

    Comment


    • #3
      Re: What did I miss

      What was the incoming voltage?

      What was voltage at elements?

      What was the amp draw?

      What was the condition of the element that was replaced?

      Did the new thermostats come with a high limit?...and was it installed tight against the tank?

      Comment


      • #4
        Re: What did I miss

        Originally posted by QROKING View Post
        Usually having a good understanding of how something works can help alot. If I am not mistaken, here is the way an electric hot water heater works. The cold water feeds into the bottom of the tank. There is a pipe that connects to the cold water inlet that feeds water in to the bottom of the tank and the hot water comes out from the top. The lower element turns on and starts heating the water, when the lower part of the tank reaches temp, then the upper element is turned on and the lower element turns off. I am I correct, both elements do not run at the same time, they alternate. Lets assume the pipe is broken off that feeds the water to the bottom of the tank, when the hot water is NOT being used, all the water in the tank will get hot. When you start drawing hot water,, the water will be hot for a little while and as the cold water comes in to the top of the tank because the pipe that feeds the cold water to the bottom is broke off will then contaminate the hot water at the top of the tank and cool it down right away. If everything is working correctly as it should since you replaced everything, then the likelyhood of what I say could be very possible. When you get to the bottom of this let us know. Lou

        Here's how those elements fire:

        On a cold tank ONLY, meaning for the first time in operation or the tank being completely emptied of tempered water...the upper element fires first.

        This is to create ready to use hot water. After that thermostat cycles, the bottom fires, but never will both elements operate at the same time.

        The bottom element is the worker bee of the unit. It does the most work as the incoming cold always enters at the low point of the tank to avoid a mix with the ready to use hot water. (Dip tube)

        The only time the top element fires is ONLY when a heater has sat for hours and the temperature of the ready to use hot water has dropped slightly. That way when you go to turn on that faucet after being gone all day....it's there.

        Top thermostat controls the actions of the lower, always. It tells the bottom to fire when the temperature drops from the contents of the tank losing temperature as cold goes in, tempering the ready to use hot.

        Bottom elements have a tendency to fail more than the tops since they work harder IMO. That situation reverses if a person doesn't spend a lot of time at their house or is gone a great deal......then the top fires constantly to maintain the ready to use water.

        There's always a 12 gallon variance on any tank you buy......You buy a 50 gallon water heater you have only 38 gallons of hot water....but that water is nearing 100 degrees by the time you reach the 30 mark.

        When you do a conversion on electric to gas, you can drop 10 gallons in size. If you do the reverse, add 10 gallons to the equation as gas is by far more efficient at heating water than electric on usually all fronts.
        Last edited by DUNBAR PLUMBING; 11-19-2007, 05:52 PM.
        Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

        Comment


        • #5
          Re: What did I miss

          Originally posted by plumberscrack View Post
          What was the incoming voltage?

          What was voltage at elements?

          What was the amp draw?

          What was the condition of the element that was replaced?

          Did the new thermostats come with a high limit?...and was it installed tight against the tank?

          Don't know

          Don't know but it passed continuity on the first try, bottom failed on the second

          Don't know

          Both were unscaled and in good condition, no buildup whatsoever

          Thermostats were OEM to the product it was made for, I then set both upper and lower at 120 degrees. I didn't even test the old original thermostats due to the fact that he told me that the water was extremely hot before it screwed up.

          On a electric water heater that keys to thermostat malfunction, I test the continuity of the elements to make sure neither were damaged in the event, replace upper/lower thermostats to blanket any chance of having to come back.


          BUT< Here's an update to this situation.

          Customer called this morning...and I mentioned this a while back that "possibly" that the breaker could of been damaged during this event. It's a Murray electrical panel and I'm told it's not the best brand out there.....HD Lowe's and practically all electrical supply houses do not stock except one....the taj ma hal of all electrical supplies have it. $14.88 for a 20amp double throw.

          He told me he woke to a cold shower, went downstairs and the breaker was tripped even though it showed it in a ON position.

          Since I live so close, he asked me to stop today and take a look, he seems to think the breaker got damaged somehow through all of this.

          My reaction time to all of this has been quick....so every time I've worked on it...I've shut the breaker down each time...meaning that I literally have been resetting this breaker possibly not knowing it was tripped.

          But by and far, I've heard/witnessed breaker failures countless times....people think that those breakers don't break and they do, especially if they've been subjected to demand nearing the maximum draw of load capacity. I've heard them hum and sing while in operation knowing that can't be good.

          All this brings me back to the very premace of why I got called out there to begin with; no hot water, extremely hot water before failure. I've replaced everything at the heater, the lower element at the bottom was different but didn't offer the ability to burn at 5500 watts, otherwise it would have a 3rd spot to screw to for a buss clip, this in turn would increase demand starting at the panel with a MINIMUM 10-2 feed and 30amp double-pole breaker.

          I'm getting a new breaker for his panel tomorrow and see if this resolves the problem.

          I know enough about electric to get me in trouble. Replacing a apple for an apple is all I want to know. Take it any farther in depth with amp draw and voltage and I just don't know it.

          The guy couldn't get an electrician to come out; so he called a plumber thinking that it could be remedied. It can....it's just that plumbers don't expect breaker failure and don't run around with 30 different models of circuit breakers for this type of problem.

          I'm just caught in the mess and thank goodness it's less than a mile from the shop.
          Last edited by DUNBAR PLUMBING; 11-19-2007, 05:55 PM.
          Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

          Comment


          • #6
            Re: What did I miss

            A 20 amp circuit is too small for a heater even at 4,500 watts per element.

            The service should be a 30 amp as you mentioned earlier.

            Not saying that is the problem, but I dont really see how it ever worked at 5500 watts with a 20 amp circuit.

            Regards,

            Comment


            • #7
              Re: What did I miss

              Originally posted by biscuit View Post
              A 20 amp circuit is too small for a heater even at 4,500 watts per element.

              The service should be a 30 amp as you mentioned earlier.

              Not saying that is the problem, but I dont really see how it ever worked at 5500 watts with a 20 amp circuit.

              Regards,


              Correct. The max is 3800 watt elements on 20 amp breaker.

              People who install Home Depot/GE water heaters find this out real quick and realize they should have a 30 amp breaker instead of the 20 they have.

              And a great deal of them don't realize the dangers when they switch the breaker and not the wire.


              The buss clip was not in use to burn the bottom element at 5500 watts. It's set up to only if the wiring/breaker requirements are satisfied.
              Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

              Comment


              • #8
                Re: What did I miss

                [quote=DUNBAR;104968]

                And a great deal of them don't realize the dangers when they switch the breaker and not the wire.
                quote]


                Seen it too many times, I see it most often when people change a 15 amp breaker with a 20 because they are tripping a 15 with a window shaker or whatever. I personally know of two fires that resulted from this. So Sad.

                Regards,

                Comment


                • #9
                  Been 5 hours

                  Replaced the breaker, all is good.


                  Did a test, ran water out of faucet for 15 minutes with continuous hot water, got bored and left.

                  That estimation was nearing 45 gallons out of a 82 gallon electric water heater.

                  Customer called, stated water was hot and was starting laundry.

                  Wanted to pay me for my time and breaker and I declined. Hardest $100 I've made in a long LONG time.


                  When I reset the breaker when I got there, instantly was humming loud. New one was completely quiet, still drawing current as revealed from test at the heater. All is well.
                  Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

                  Comment


                  • #10
                    Re: What did I miss

                    Glad it worked out for you, and you probalby got a customer for life out of it with some good referrals.

                    REgads,

                    Comment


                    • #11
                      Week later, plenty of hot water

                      Checked on my customer yesterday and told me he's back to normal and all is fine. He offered to pay for my time and the breaker and told him that it wouldn't be necessary.

                      Just glad it's a memory now. I guess I'm going to weigh more into letting people know that it could affect the breaker serving the unit....next time around.
                      Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

                      Comment


                      • #12
                        Re: Week later, plenty of hot water

                        Originally posted by DUNBAR View Post
                        Checked on my customer yesterday and told me he's back to normal and all is fine. He offered to pay for my time and the breaker and told him that it wouldn't be necessary.

                        Just glad it's a memory now. I guess I'm going to weigh more into letting people know that it could affect the breaker serving the unit....next time around.
                        I don't see what the breaker had to do with it.
                        Was the breaker tripping?
                        Was the breaker defective?

                        If you installed a 30a breaker to replace a 20a do you have 30a or 20a rated wire on the breaker?
                        Last edited by bluecon; 11-30-2007, 11:23 AM.

                        Comment


                        • #13
                          Re: Week later, plenty of hot water

                          Originally posted by bluecon View Post
                          I don't see what the breaker had to do with it.
                          Was the breaker tripping?
                          Was the breaker defective?

                          If you installed a 30a breaker to replace a 20a do you have 30a or 20a rated wire on the breaker?

                          Had everything to do with it when the thermostat malfunctioned, created a load back to the breaker, the breaker hung up or was of "imperfect" quality and became defective.

                          Is this the norm? (breaker malfunctioning)

                          Of course not, but evidently it happened in this case as I troubleshooted the heater to death which led me back to the panel. Replaced breaker: no humming anymore: withstands load without tripping to this day.

                          Was the breaker tripping?

                          Yes.

                          Was the breaker defective?

                          Yes.



                          You're last question I believe was not intended to be sarcastic, so I'll answer with the fact that I do know amperage capacity for the different sized wires in relation to the load they are considered safe to carry.

                          It was a 20 amp breaker that was defective, a 20 amp breaker that went back. It was 12-2 wire and for that reason it cannot be ran with a 30 amp cirucuit. < 10-2
                          Northern Kentucky Plumbers Twitter Feed | Plumbing Videos

                          Comment


                          • #14
                            Re: What did I miss

                            But 12-2 wire and a 20a breaker is to small for the application.
                            It might work but it is does not meet code.

                            Wasn't meant as sarcasim.
                            Last edited by bluecon; 12-01-2007, 12:02 PM.

                            Comment

                            Working...
                            X