pressure relief valve test

[thesaintjim]

Hi,

I tested my pressure relief valve today as it has been a year and when I pushed up the silver tab to see if water comes out, water actually was dripping from the silver tab when it was pushed up all the way. If I lift it a little, nothing leaks. Let me note that the actual drainage works just fine, but it is just a small leak when letting all the water come out. I attached a picture to better explain myself. I am just not sure if this is normal or not as it is my first house

http://i.imgur.com/kzkLw.jpg


Thanks in advance.

update: from what others have said, this is normal, so this can be solved.

 

[johnjh2o]

It's normal. But some day your going to open it and it won't close. After setting for some time when you open it rust or scale can get caught on the seat and the valve won't completely close. Then it's time to replace it. Just what are you trying to test?

John

 

[thesaintjim]

Actually, I am testing just that, making sure the valve completely closes.

 

[speedbump]

I learned long ago not to fool with that little lever. Just like johnjh2o said, they can and usually do leak once you lift it up.

 

[DCPlumber]

I've read the label on some T&P valves. It actually says that you are supposed to test them once a year. Apparently this is a good idea so that they don't get stuck in the closed position, creating a potential bomb. Do a search on youtube. I'll bet you can find the one where a water heater exploded and went through a cafeteria wall at a school. But, I know, you touch them and they leak.

 

[havasu]

I was always taught to test them as well. If it starts leaking, then I will replace it. Better safe than sorry.

 

[EricS]

Definitely worth testing. Mythbusters has a video on youtube worth checking out that shows the damage that a non-functioning relief valve could cause.

 

[speedbump]

I've read the label on some T&P valves. It actually says that you are supposed to test them once a year.

That's what keeps them in business.

 

[johnjh2o]

I've read the label on some T&P valves. It actually says that you are supposed to test them once a year. Apparently this is a good idea so that they don't get stuck in the closed position, creating a potential bomb. Do a search on youtube. I'll bet you can find the one where a water heater exploded and went through a cafeteria wall at a school. But, I know, you touch them and they leak.

I'm also sure if you look hard enough you could also find a toilet that explodes. So maybe we should pull are toilets two times a year to be sure there OK. I would be very suspicious of any thing you see on the internet.


John

 

[KULTULZ]

Some manufacturers (Rheem) recommend that the temperature and pressure safety relief valve be tested once every six months. To test the valve the lever on the valve is lifted, which should result in (hot) water flushing through the valve and its discharge tube into a bucket placed below the discharge tube for that purpose or into a floor drain.

After lifting the easing lever or relief valve opening lever, lower it gently back to its closed position. Rheem points out that rough handling of the relief valve test lever, such as allowing it to "snap" closed, can damage the temperature and pressure relief valve - a dangerous condition that could lead to a water heater explosion or BLEVE explosion.

If water does not flow freely when the temperature/pressure relief valve is opened, the valve should be replaced by a licensed plumber, making sure that an approved, properly-rated TP valve is installed.

If your temperature/pressure relief valve has not been tested or replaced sooner than five years, Rheem recommends that the TP valve should simply be replaced. More frequent replacement of the safety valve may be needed in areas where hard water is found.

SOURCE- Temperature Pressure Relief Valves on Water Heaters: test, inspect, replace, repair guide

 

[plumberhep]

'Testing' a t&p relief valve can mean different things in different applications. For the average homeowner, you should be concerned mainly with unrestricted movement of the (in this case) silver tab and shaft it is connected to, and the discharge tube location / condition. I personally prefer the tube to discharge outdoors to prevent water damage in case the valve does open, but you should check your local building codes as that's not always allowed believe it or not!

The only way to truly test those valves is to connect them to a device that will bring them to the pressure that they should relieve, and then the temperature at which they should relieve, but you would never do this for your typical home valve as it would be far less expensive to simply replace the valve periodically.

Don't forget that part of your regular testing and maintenance should include flushing the buildup from the bottom of your water heater. This will extend the life and make the heater more efficient. Like the t&p valve, however, once you open the drain valve it may not close again without leaking. They are generally very easy to replace, so no big deal, just put a good quality brass valve in instead of the cheap plastic thing many home heaters have from the factory. I'm sure there are many posts here already to explain this further, but you're welcome to write and ask for details if you like.

 

[havasu]

I agree 100% about replacing those cheap plastic spigots with a nice brass valve.