Weil mclain he5


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Old 02-03-12, 12:34 AM
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Weil mclain he5

Hi all

I have old Weil mclain boiler.
Expansion tank keeps filling up and
the pressure relief valve opens.
So I have to drain water from tank
every couple of days. There must be leak somewhere.
Does anyone have any ideas how to find leak in system?
There is no visible water anywhere.
 
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Old 02-03-12, 09:48 AM
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The assumption is this is and old style expansion tank, horizontally mounted up in the floor joists?

Or is a new style one, hanging in a vertical position?

Peter
 
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Old 02-03-12, 02:48 PM
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Yeah, tell us what kind of expansion tank you have.
 
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Old 02-09-12, 12:53 PM
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Yes it is definitely the old style tank hangs from the floor joists.
has a spigot in the bottom. Looks to be about 10 gallon.
Thank you for your replies!
 
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Old 02-09-12, 02:55 PM
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Hi Old Dude, I wouldn't think the problem is due to a leak... if you had a leak, why would you have to drain water out? Wouldn't it leak out?

You are probably not completely draining the tank properly.

Is there a valve on the pipe leading to the tank from the boiler?

Are you able to take some pictures of your system? If so, set up a FREE account at Image hosting, free photo sharing & video sharing at Photobucket and upload the pics there. Come back here and place a link to your PUBLIC photo album.

Please make sure that pics are IN FOCUS, WELL LIGHTED, and LARGE ENOUGH for other old dudes to see the details of the system. In addition to any closer shots (try to show us all the piping and valves around the boiler) STAND BACK and take some wider angle shots of the entire system from several different angles.
 
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Old 02-13-12, 08:33 AM
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Pictures Expansion tank

Furnace pictures by gabmuks - Photobucket

I hope I did this right with the photo bucket site.
 
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Old 02-13-12, 04:25 PM
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You did it right Old Dude...

Here's what ya wanna do:

Turn the boiler OFF and allow to cool.

Connect a drain hose to the drain valve on the tank. Direct hose to floor drain, sump pit, laundry tub, bucket... whatever. Use the shortest, largest diameter hose you own.

CLOSE the green 1/4 turn valve on the pipe leading to the tank.

OPEN the drain valve and allow to run until it stops.

On the bottom of the red B&G ATF there is a 'vent' fitting. OPEN that (have a bucket handy in case any water comes out). That vent should draw air in, and the hose should run some more.

Let the tank drain COMPLETELY.

CLOSE the vent on the ATF, CLOSE the drain valve, OPEN the 1/4 turn valve.

You should hear water flowing back into the tank. That's NORMAL. In operation the tank will be half full of water. The rest will be the air that was in the tank after it was drained compressed to form a 'cushion' for the expanding water.

MONITOR the PRESSURE. After the tank is back on-line, the boiler pressure should be set to 12-15 PSI when the boiler is COLD. It should not rise above 25 PSI when HOT, and probably will be less than that.

If the pressure STILL goes out of control, then there is something else to look at, but try this first and we'll go from there.
 
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Old 02-13-12, 04:27 PM
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Take some more pictures... STAND BACK! and take some of the whole system. If you know which pipe feeds water into the boiler, take some shots of that also, I want to see the water feed valves and such.

Show us a clear photo of the gauge also.
 
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Old 02-16-12, 12:11 PM
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Thanks NJ. I think you are right. I was not draining all the water completely from the tank.
After performing your instructions, so far the pressure is maintaining at the PSI ranges that you have given me.
Since then, I have not seen the hot pressure go above 25 PSI. But the safety pressure valve still spits out some water occasionally. I might have some dirt stuck in it or maybe can be adjusted. I will try to get photo of safety valve
and rest of boiler as you have requested. Thank you much for your help NJ Trooper!!
 
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Old 02-16-12, 02:53 PM
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the safety pressure valve still spits out some water occasionally. I might have some dirt stuck in it or maybe can be adjusted.
You could be right... but it could also be that your pressure gauge is not accurate and lying to you! It's probably not a bad idea to replace that valve, especially if it's more than 5-10 years old.

Read this about pressure gauges:

http://www.doityourself.com/forum/bo...ure-gauge.html
 
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Old 02-28-12, 09:01 AM
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Well I noticed a puddle of water on the floor from the pressure relief valve again.
So I turned up thermostat to watch pressure build up. And sure enough, the pressure
gauge went up to 30 psi (too high) and the relief valve immediatedy opened up.
I'm guessing that the pressure gauge and relief valve are still functioning correctly.
I'm going to have to drain tank again. Could there be an air leak in the expansion tank?
Can I install a bladder type tank? Is there any other way that air in the tank can leak out?
I will try to give more pictures of boiler. But they are blurry. My hands must not be too steady.
 
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Old 02-28-12, 09:33 AM
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Furnace pictures by gabmuks - Photobucket

Tried to put all furnace pictures in same file.
Here goes......
 
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Old 02-28-12, 02:34 PM
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I doubt that the tank has lost it's air already. Assuming that you are SURE that you got all the water out last time drained.

There's TWO things that can cause problems such as this.

1. The expansion tank being water logged.

2. THE AUTOMATIC FILL VALVE leaking through into the boiler and s-l-o-w-l-y increasing the pressure by adding water.



See the red bell shaped thingy on the water line feeding the boiler? That is your "Pressure Reducing Valve" or "Automatic Fill Valve" (and other not so nice names!)

It's job is to fill the boiler when the boiler is COLD up to 12 PSI. It's not supposed to add more water if the pressure is above 12 PSI, but sometimes they leak.

I can't see one in the pictures, but there MUST be a MANUAL shutoff valve on that line. Is there?

If so, here's what to do to determine if that valve is the problem:

1. Shut off the boiler and let it cool all the way down.

2. CLOSE the MANUAL water valve feeding the boiler.

3. OPEN a boiler drain valve and let enough water out to drop the boiler to 12 PSI on the gauge.

4. Turn the boiler back on and run it with the manual valve closed for a couple days while periodically monitoring the pressure gauge.

If the pressure stays under control now, you know that the red reducing valve is bad.

You CAN run the boiler this way until you can replace that valve as long as you MONITOR the pressure from time to time. As long as it stays between 12 and 25 you will be OK. If you notice that the pressure goes below 12 PSI, open the manual valve and feed a little more water in until it is again at 12 PSI and close the manual valve again.
 
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Old 02-28-12, 02:37 PM
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Here's another view of the reducing valve. This photo also shows an 'Automatic float type air vent'.



With the type of expansion tank that you have on your system, the black cap on top should be screwed down tight when the system is operating.

That one looks like it's leaking a bit too... but as long as it doesn't leak when the black cap is tight, just leave it be.
 
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Old 02-29-12, 06:38 AM
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Thanks NJ Trooper for your reply.
I had already drained the tank before I read your reply.
Took out about 13 gallons from the tank with the supply valve closed
and the valve from the boiler to the expansion tank also closed.

What I have been doing for the last two years is exactly what you have suggested.
I would let the boiler reach 12 psi (cold), and then shut off the supply valve to the automatic fill valve. The 12 psi used to remain for a couple of days until I had to let in more water.
But now it doesn't even last a day before I need to refill.
I will try tightening down the black cap on the automatic float type air vent. I've kept it at a half of a turn open.

Thanks again NJ
Would a bladder type tank make any difference?
 
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Old 03-01-12, 02:24 PM
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The 12 psi used to remain for a couple of days until I had to let in more water.
As a point of reference, I NEVER have to add water to my system, and if you have to add water every few days in the past, to me that says that there is a leak somewhere. Thing is, with a heating system, you won't actually SEE water usually because it evaporates almost as soon as it comes out. You see that greenish white deposit on top of the air vent? Start examining every inch of pipe that you see, especially around fittings, for that same sort of crusty mineral build-up.

Would a bladder type tank make any difference?
I'm not convinced that there's a problem with your existing tank, so I would say it probably wouldn't be of any benefit to change.
 
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Old 03-08-12, 02:24 PM
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Thanks NJ Trooper

I will do that as soon as I
get back from vacation.
What are your thoughts on pressure testing the system somehow
to find the leak? Maybe doing one zone at a time?
Do you know of a way to pinpoint leaks such as these.
I have found the greenish white deposit on some of the fittings
in the past, and have soldered in new fittings to replace them.
But I cant check inside the walls. The ones that I have found
and replaced are on the exposed copper pipes in the basement.
Can I pressure test with air somehow during the summer months?
Also since there is the greenish white deposit on the air vent,
should I replace the air vent maybe? This is the first year that
deposit has been on the air vent. Another thought, could the
air vents on one or more of the baseboards be leaking? Should they be replaced regularly?

Thank you NJ Trooper.
 
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Old 03-08-12, 02:30 PM
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I don't think pressure testing is going to find anything more than you would find by looking... after all, the system IS pressurized already. Using air to pressure test a system is really never a good idea, there is a lot of energy stored in compressed air, and how would you find a tiny pinhole air leak anyway?

Also since there is the greenish white deposit on the air vent, should I replace the air vent maybe?
I don't think so... just screw the cap down tight, it should stop leaking. With the type of expansion tank that you have they should be tight anyway, and only used when filling the system after servicing...

Another thought, could the air vents on one or more of the baseboards be leaking? Should they be replaced regularly?
They could be leaking... I would only replace them if they are found to be leaking. Are they the same type as the one on the boiler? If so, close the cap on all of them.
 
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Old 03-08-12, 03:16 PM
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Thanks for reply NJ.

The air vents on the base boards are only about the size
of my wife's fingertip. Some are closed via a flat tipped screw driver.
And the rest require a small clock winding type, square drive key.

Sounds like the only thing I can do is to find any greenish joints and fix.

Only other thing I haven't told you is, there is an old style radiator
in the bathroom. Do those have a tendency to leak at the joints?
 
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Old 03-08-12, 03:44 PM
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Those small manually operated vents are what you want. They rarely leak.

Only other thing I haven't told you is, there is an old style radiator
in the bathroom. Do those have a tendency to leak at the joints?
No, I don't think so... but if they did, you would probably see the mineral deposits.
 
 

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