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I have a hot water heater relief valve that is leaking heavily. The water heater manual states I should replace the valve (which is OK by me).

Unfortunately, I am not able to remove the valve as it is in too tight. Are there some easy tricks to loosen it?

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Spray the threads with wd-40 to loosen any rust or other buildups. Get a bigger wrench. Note that if the threads are too far gone, you may not be able to install a new valve. You should also verify that the fault is a bad valve and not high water pressure or excessive temperature. – BMitch Jul 29 '13 at 1:34
use a longer blue tool in the image i don't know what it is called encrypted-tbn2.gstatic.com/… – Dimensionless Jul 29 '13 at 12:18
@BMitch - Threads are too far gone... With anything stuck on a water heater, experience tells me that a good deal of rust is probably involved. Which means "DON'T FORCIBLY REMOVE IT UNLESS YOU'RE PREPARED FOR FULL WATER HEATER REPLACEMENT", i.e. have a new unit chosen and available for purchase before proceeding. Been there on that one, emergency replacement stinks, the element did come out, but nothing was going to seal when the new one went back in. And if it's got a good grip on brass... – Fiasco Labs Jul 29 '13 at 14:55
@Akash That's a "pipe wrench." It's good for torquing round pipes, and being used on gas lines in that photo. For a bolt or anything with a flat side (e.g. nuts, bolts, and probably the pressure relief valve), you want to use a "crescent wrench" which should do less damage to the surface. – BMitch Jul 29 '13 at 15:56
up vote 1 down vote accepted

Lefty Loosey

The first thing you'll want to do, is to insure you're rotating the proper direction. Make sure you're rotating the valve in an anticlockwise direction.


Apply a liberal amount of penetrating oil; allowing it to soak in for a bit, then give it another try. This will help clean the threads, as well as providing a bit of lubrication. Giving the threads a good second blast of penetrating oil can often remove more dirt and corrosion, which can be just what's needed to get the valve turning.

Penetrating oil

Size can matter

Using a wrench with a longer handle; or a breaker bar, can often help loosen stuck valves. Just be careful, you may be able to exert enough force to actually snap the valve.

Tap and twist

Tapping the end of the wrench with a non-marring mallet, can also help loosen a stuck threaded joint. Again, too much force can cause collateral damage, so be careful. Place the wrench on the valve, and gently rap the end in the direction of rotation.

Rubber Mallet

Make sure you have the water heater inspected for proper operation, before and after replacing the temperature and pressure relief valve. Once installed, test the new valve to insure proper operation.

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