Replacing pressure relief and checking air tank

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Old 02-28-11, 05:15 PM
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Replacing pressure relief and checking air tank



I am going to replace the leaky pressure relief valve this weekend and want to get it right.
The pic is a bit fuzzy but:
1) Cool boiler
2) I shut off the lever circled in yellow, this the valve where you add the water very fuzzy).

3) To change the relief valve I would have to shut the valves circled in red and let the water out at the valve circled in green to zero and replace the valve.
4) Then re pressure the system to 12 to 15 cold

If I wanted to check the air in the air tank I am assuming I would shut the zone valves after the tank circled in blue (very fuzzy and hard to see) and leave the right hand red circled valve open. This would include the air tank in the isolated zone.
With the pressure at 0 pressurize to 12 psi.

Another question is how much water will come out to get the pressure to 0

Sounds pretty straight forward and I did a search so I think I got it.
 
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Old 02-28-11, 05:24 PM
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Yes all you say is correct. Close off valves to boiler mate if their there.

I would say about a gallon of water or so to get 0 psi. I would also change the airvent (little can above exp. tank) while your at it.

Also when you fill the boiler make sure the auto fill valve fills boiler to 12 psi. This is what they are preset to.

Mike NJ
 
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Old 02-28-11, 05:50 PM
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Dropping the pressure in the boiler to zero will allow you to change the relief without water coming out UNDER PRESSURE, but you may still have some flow out by gravity... the water above the level of the relief valve may want to flow a bit... but with the two red valves closed you might get lucky and none will flow. In any case, be prepared to work quickly when you take the old valve off... have the new one ready to go within reach... and please, don't freak out with the teflon tape! TWO WRAPS is more than enough, and keep any tape or pipe dope off the first two threads of the valve. You want those first two threads METAL TO METAL.

I'm betting way less than a gallon... wouldn't surprise me if it's less than a quart!

As for the tank charging, you can actually do this with the zones open/closed, don't matter... as long as the pressure at the tank water side is at zero.

Here's the thing... if the air charge in the tank IS very low, there will be water in the tank. When you add air, you will push some, but not all of that water out. When that water pushes out into the system, the pressure in the system may rise. So, after the first dose of 12 PSI air in the tank, check the boiler gauge and drain a little more water if needed to drop the boiler back to zero. Then recheck the tank. Repeat until the boiler gauge stays at zero, and the tank stays at 12.

If you get any water out of the air valve, replace the tank.
 
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Old 02-28-11, 05:58 PM
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The thing above the expansion tank says spirovent, micro bubble resorber. Do they go bad?? I am pretty sure I heard air come out of it when I flicked the relief valve. Changing that looks a little more into it than I want to go, especially if it is not bad. Don't know if I could get it off with out cutting and sweating some pipe. Pipe is threaded in on both sides.

Thanks I thought I had it right, but it's nice to know for sure.
 
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Old 02-28-11, 06:03 PM
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Yeah, I thought it looked like a Spiro... I'm sure it's OK. The top does unscrew on those if needed to clean them out, but don't fix it if it ain't broke.

Is there something between the tank and the Spiro? A valve perhaps?
 
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Old 02-28-11, 06:05 PM
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One more thing I wanted to mention... because I know you are going to ask at some point...

When your boiler starts up, and the pump runs, I would expect that you will see the pressure gauge on the boiler drop, perhaps as many as 5 PSI. Not to worry about that, it's because of the pump position in relation to the expansion tank.
 
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Old 02-28-11, 06:17 PM
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Nope, just a T to the valve where you add water. I do lose 5 psi or so when the Pump is on. I have researched pumping away. As far as the air tank the Plumber said he had to blip the schrader a few times because it was leaking bit. I check it and it is still holding fine, but I thought I would take the time to change it when I had the pressure down
 
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Old 02-28-11, 07:14 PM
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he had to blip the schrader a few times because it was leaking bit
They do that more often than ppl realize I think... it's a standard schrader valve and can be easily replaced if need be. Auto part store will have them, and the little tool to remove and replace. If in doubt about it being sealed, a little spit, or a soap solution will tell you in seconds.

For that little bit of extra seal, pick up a METAL cap, the kind with a rubber gasket and screw that on when yer done.

I wonder how many perfectly good tanks are replaced because a 49 cent air valve is leaking?
 
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Old 03-04-11, 08:22 PM
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Well I changed the Pressure relief valve and the schrader tonight, it took more time for the boiler to heat up after than it did to change both . All went smooth, it was less than a quart that came out to go to 0 pressure. Filled the pressure tank to 12 and when I opened up the auto fill valve the pressure went right up to 12 an stopped. There was a little seepage (very little like a few drops) from the relief valve when I checked after the boiler was up to temp, but that was it. 3 hours later all is still dry so we will see if this fixes it. All I have left to do is to re sweat and reinstall the copper drain pipe from the valve
My cap is plastic but it does have an O ring seal on it.
 
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Old 03-04-11, 11:49 PM
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All I have left to do is to re sweat and reinstall the copper drain pipe from the valve.
Do yourself (and the next guy who has to change the safety valve) a favor and install a union so that you don't need to unsolder the piping to change the safety valve. You should change the safety valve every five years just as a matter of preventive maintenance.
 
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Old 03-05-11, 12:26 PM
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install a union
Union, or a male and a female adapter so you can remove the downpipe easily. Might be a few bucks cheaper for the adapters?
 
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Old 03-05-11, 02:08 PM
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I forgot to say that there did look to be a bit of junk in the old valve and I did notice some green flecks in the water when I drained it. I am assuming it is from the copper pipe.
As far as a union or something I will see what I have in my box of parts. I did not come off and down from the valve. I ran ran the pipe to the back of the boiler. If it comes straight down from the valve and it ever blew a good one it would probably get the electronics in the front wet. I moved it to the back to keep it away from all that stuff.
 
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Old 03-05-11, 05:15 PM
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You should turn it down and about 6" away from the floor , whether in the front, back, or side.
 
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Old 03-05-11, 05:50 PM
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Yep, that's what I did. Slight downward pitch and then turned down to the floor.
 
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Old 03-05-11, 09:49 PM
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Originally Posted by NJ Trooper View Post
Union, or a male and a female adapter so you can remove the downpipe easily. Might be a few bucks cheaper for the adapters?
Union, thread adapters, Shark-Bite or whatever, just make it so it is unnecessary to unsolder or cut the piping in order to replace the safety valve. The same holds true at the make-up water supply (backflow preventer and pressure reducing valve) plus have valves on both sides of these parts.
 
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Old 03-10-11, 04:42 PM
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Thanks to everyone. I am on day 6 with no leaks at all. I would not have even known where to begin with this forum. Over the past 6 months or so I have gained a comfortable working knowledge of what the parts are on my boiler and how they work. I try to visit everyday just to learn more.
 
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Old 03-10-11, 05:03 PM
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Great! Good job there... stay warm!
 
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Old 03-30-11, 02:23 PM
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water coming out of resorber

I have water coming out of my spirovent microbubble resorber. I had a repair guy come and say that the rersorber and the expansion tank needs to be replaced. Because the gasket in the tank probably blew. Do I really have to replace BOTH the resorber AND the tank? The tank is sealed, so I don't think I can replace the gasket. But can't I just replace the tank?
 
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Old 03-30-11, 04:29 PM
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If you've got a Spirovent, they can be opened and cleaned. You probably have some 'crud' stuck under the valve. Here is a PDF file that explains the procedure:

http://www.spirotherm.com/docs/installation/JrIOM-A.pdf

You will of course need to drain the system unless you have valves positioned such that you can isolate that portion of the piping.

Here is a source of the vent head if it needs replaced:

Patriot Supply -

If the O-ring is damaged when taking it apart, you can likely find a proper replacement at any good plumbing supply store. Bring the old one with you and match it up.

There is no need to replace the body of the valve.

If the tank is bad, and needs replaced, that's one thing. If there is water leaking from the Spirovent, that's a whole 'nother issue, so I would say, Yes, they both need work... but replacing the entire Spirovent is probably not necessary.
 
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Old 04-01-11, 04:48 PM
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Spirovent/Bleeding

Great! I'll take the Spirovent out tomorrow and clean it to see if that works. At the end of the pdf link that you sent me it says that I have to do manual bleeding. How do I do that?
 
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Old 04-01-11, 06:53 PM
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I don't think it's a great idea to just jump into this... if you are going to drain the system to take the Spirovent apart and clean it, there is no point in not also replacing the expansion tank at the same time. It just doesn't make any sense at all to go to the trouble of draining to do the SV and then draining again to do the tank!

You need a STRAP WRENCH to get that top off the vent. If you try to use a plumbing wrench you will bugger it all up.

I have to do manual bleeding. How do I do that?
In order to properly answer this, we would need to see pictures of your system to see what valves you have where, so we can tell you which ones to turn when...

Take IN FOCUS, WELL LIGHTED, and LARGE ENOUGH TO SEE pictures (cell phone pics generally 5uck) and set up a free account at Image hosting, free photo sharing & video sharing at Photobucket and upload the pics to a PUBLIC album. Past a link to your album here for us to view.

We need to see, in addition to any close-up shots, several shots of the entire system taken from several angles. We need to see everything!

Please, don't jump into anything that you have the slightest doubt about being able to complete. We can't judge your skill set, only you can do that! We can tell you how, but don't be hasty.
 
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Old 04-01-11, 06:55 PM
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By the way, keep in mind that cleaning doesn't always work... so it might not be a bad idea to have a replacement head on hand... just a thought.
 
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Old 04-02-11, 01:19 PM
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Thanks! But I was trying to separate the head from the spirovent and i'm having a hell of a time. Right now I'm using two pipe wrenches (one to keep the bottom from moving while I'm trying to loosen the head) but it just won't budge. Will two strap wrenches work better to get it loosened up?
 
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Old 04-03-11, 09:07 AM
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I would think that if you can't get it off with a couple ample sized pipe wrenches that the strap wrench might not be worth trying... can't tell from here!
 
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Old 04-03-11, 09:54 AM
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Those SV heads can be incredibly tight. Lefty loosey.
 
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Old 04-08-11, 03:17 PM
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I do plan on replacing the tank and the Spirovent head (if needed). I have all of the parts ready to go. Here is a link showing my system:

Boiler - Windows Live

There are 3 zones (1- Main level, 2- master bedroom, 3- basement).

I was asking about the bleeding because once I have everything replaced I want to make sure I know everything to be done to get the system up and running.

Thanks for your help.
 
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Old 04-08-11, 03:51 PM
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John, I've gotta head out for the evening, when are you planning on doing?

Maybe one of the other guys will be able to drop in and give you some pointers on bleeding out the system when yer done...

You sure that tank is actually bad? Looks pretty new to me... might just need an air charge... was there any water coming out the air valve on the bottom of the tank? (you might have told us already but I'm too lazy to go back and look)...
 
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Old 04-11-11, 12:28 PM
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I plan on replacing the tank and cleaning out the Spirovent head tomorrow. And I have a spare head just in case it needs to be replaced. The system is 11 years old. And no water was coming out of the air valve at the bottom of the tank. Only from the Spriovent head.
 
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Old 04-11-11, 04:55 PM
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In that case I'm betting that the tank is just fine... probably just needs a charge.

Check the air charge on the new tank before installing.

I'll try to check in tomorrow from the day job and see how yer doing...
 
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Old 04-12-11, 12:33 PM
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Once I was able to get the head off everything was easy. I cleaned the head out and let it soak. But when I put it all back together it was still leaking water. I then replaced the the head and everything worked just fine.

For the tank it would not hold a charge. So I just replaced it with the new tank.

Everything is working fine and I have heat in all three zones. Thanks for you help!
 
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Old 04-12-11, 03:49 PM
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Great! saved yerself a bunch of cash too... I like a happy ending!
 
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