I have the below T&P valve, I'm not able to remove it to replace a new one. I saw there has some declaration above the valve which said it's the combination of the water heater, does this mean I can't remove it? If no, how to remove a very tight valve. Thanks a lot.

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OK, that warning label is telling you that the valve is protecting the appliance from both over-heating and over-pressure (combination). The part about removal from point of installation is a warning that relocating it to another part of the system will not provide adequate protection (back in the day they sometimes located a pressure-relief valve on a pipe outside the home). You can remove and replace it. Pull off that plastic cover so you can see the threaded part. Get a bigger wrench, at the factory they use a pipe compound that sets hard. Your tank is iron and unlikely to be damaged

  • My tank is more than 10 years old, I worried about will break the screw there, then not able to tighten the new one properly. I already got a 14inch pipe wrench but doesn't work, so you think I need a bigger one like 18, 24 inch. besides, the cover not able to peel off as new picture attached. @Jimmy Fix-it – Brian Z Dec 28 '18 at 1:20
  • I have attached a pic for comparison between the old and new PRV, do you think that work? – Brian Z Dec 28 '18 at 4:04
  • It absolutely will work, if it has the same temp. and pressure ratings (your old one is 150 p.s.i. and 210°F). The pic does not reveal the rating of the new one. – Jimmy Fix-it Dec 28 '18 at 5:51
  • how about a longer neck than those two above, I mean the one has a shorter exposed length of the probe, is this matter? Attached a pic for the that one. @Jimmy Fix-it – Brian Z Dec 28 '18 at 18:41
  • No, probe length relates to function. Even if it had the same temp. rating the location of the probe in the tank would be different. Use the one with the probe position closest to the original. Why are you proposing to use the "long-neck" one? – Jimmy Fix-it Dec 28 '18 at 20:42

First, try to tighten the relief valve to break the hold of the dope and threads. It should be easier to tighten than to remove. You only have to move it a little to break the thread hold . Then remove the safety valve with a bigger wrench, say an 18" or 24" crescent wrench. The tightening is easier since the strain on the threads is in the direction of tightening.


If the TP valve is bad, you have to replace it, even if it's risks damage to the threads. I had the same problem and borrowed a long pipe wrench to get it off. You can try to break it free a few ways:

  • Use a longer wrench or put a pipe over the handle to make your lever longer
  • Rock it tighter and looser to get the threads moving
  • While the tank is hot, drain below the valve and apply ice water or dusting spray to the valve to try to change the size to loosen
  • Use a penetrating oil or something like CLR (you should be able to pull back the plastic cover to get to the threads)

Try to use even force to try to keep from tearing the threads.

If it does tear out the threads you may need to clean them out or even repair the threads with a tap.

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