Removing a Combo Anode

The Tank Removing a Combo Anode

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    Thanks so much for your help. This website is AMAZING, and I may buy an anode rod and maybe a dip tube from this site if needed. I’m trying to check out my anode rod and dip tube and have some questions:

    In regards to the anode rod:

    1) Do I need to drain out any water first, before removing the hot water pipe?

    2) If Yes, Will it be bad to drain the water out without keeping the tpr valve open? (I don’t know how to keep it open without standing there lifting it up the whole time, and I also don’t know the purpose of keeping it open during draining. Lots of websites say to keep it open, but when I asked my manufacturer how, they said to keep it closed.)

    3) I started loosening the nut without draining any water. I saw water starting to seep out from the nut area. Should I worry?

    4) The copper pipe is warm/mildly hot to the touch. Do I have to turn the pilot to off, and then wait a few hours? Or if I can handle the temperature to touch, it’s OK to handle? I’m afraid of hot water spilling out on me or something. I don’t know if there’s water sitting in the pipe or not. (where the pipe runs from the wall to the heater.)

    5) How do I practically do a measure to see how much water is being used during a shower, and whether my 40 gallon tank is enough for that one shower?

    6) When I use hot water during a shower, does cold water simultaneously enter in through the dip tube, keeping the tank full at all times?

    How long does it take for that new cold water to heat up? a few minutes? or more like an hour?



    Larry Weingarten

    Hello: I’d like to preach a little and then answer your questions :cool:. Safety is VERY important to me/us. Information in the hands of someone who may not have the proper foundation to put it on can be a deadly thing. If you’re not familiar with plumbing there is no shame in getting the help of someone who is and then telling them exactly what you want done. Now let me hop down off my soap box…

    1. Yes. The water level in the heater needs to be lowered a little and there must be no pressure.

    2. Open a hot tap and use the heater drain to remove some water. The relief should be tested periodically, but with the knowledge that it may fail the test and start leaking– needing replacement.

    3. Worry :shock:! That means there is water pressure in the tank.

    4. Done right, you should not even get wet except for the water on the old anode. The heater should be turned down to the pilot position whenever the water supply is off.

    5. If you run low or out of hot water during your shower than your heater is not meeting your needs. Normally a 40 gallon gas heater will supply a family of four. You can measure shower head output by collecting the water for 30 seconds, measuring it and doubling that number. That is your gallons per minute or GPM. You get roughly 75% of the volume of your heater as undiluted hot water.

    6. It is the incoming cold water that pushes hot water from the tank, so yes, the tank stays full.

    6.5. Recovery rate is decided by the size of the burner and number of gallons, but as a very rough approximation, one half hour is a good “time to reheat” guess.

    Yours, Larry


    Thanks for your concern for safety; it’s very much appreciated!

    I do have a few follow up questions.

    1) Is it necessary that I let the tank cool down for a few hours before handling the anode rod and dip tube?

    2) When I drain some water out from the drain valve, how will I know when there’s “no pressure” anymore in the tank? Is there a test to check for pressure?

    3) Do I have to keep the TPR valve open the entire time while I drain? I hope not, because ours doesn’t even stay open unless I stand there and keep lifting it open.

    4) Is it Ok that I don’t have a replacement anode rod or dip tube on hand right now while checking the anode rod and dip tube? I just want to check it first and see if they’re doing alright.

    After I do a “check” on the anode rod and dip tube, is it OK if I just screw the nuts back on tight with the pipe wrench and adjustable pliers, WITHOUT using tape or compound, temporarily until I order new parts (ie, anode rod/dip tube if needed)? Or is it hazardous to not use the tape or compound in the meantime? (It doesn’t even look like anything was used in the first place.)

    5) Finally, how long or how much do I drain the water out for, if I’m simply draining for the purpose of checking the anode rod and dip tube?

    Thanks a bunch for your help on this website!

    Larry Weingarten

    Hello: 1. It depends on how hot the tank is. I’d just turn it to pilot after (or before) the last big use at the end of the day and work on it the following morning.

    2. There is pressure in the tank if water seeps from the top plumbing as you undo it. Open the drain after putting a hose on it. Also, open a hot tap to allow some air in.

    3. The T&P does not have to be used. Open a hot tap.

    4. It is OK not to have the parts, but your options are limited and you may get to take things apart twice instead of only once. If the part you’re removing gets messed up and you have no replacement, it is a problem :shock:. Always put teflon or pipe dope on threads when reassembling. Flex connector ends have a rubber washer and do not need to have teflon.

    5. You only need to remove pressure. If the shut off valve works well, you may only remove a cup of water, but if the valve leaks and you work slowly, it will be much more.

    Good luck!

    Yours, Larry

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