Peerless Hot water Boiler Pressure reaching the MAX !!!!

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Old 01-16-08, 11:25 AM
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Peerless Hot water Boiler Pressure reaching the MAX !!!!

Hi all,

I have a Peerless Boiler, that was for a 2 unit Building, but now I have removed the Radiators in the second floor.

So its only heating up one 1300 SQ FT APT. (5 rads)

Here is the issue - the pressure goes to the max on the reading gauge when it heats up. I think 90PSI.

Here is what I tried :

1. Drain entire system. and with boiler off, allow water to fill it. Read the pressue - 11-14 PSI. Inlet water supply still open.

2. Start boiler, as it heats up, the PSI Flies up. Max 90PSI, it usually gets to this. Inlet water still open.

3. When the PSI was that High, I let air out of the Expansion tank, its inline and about 1.5ft tall grey tank. Water filled the tank and pressure went down.

4. As boiler got hot again, pressure went back up to 90PSI.
Expansion tank is now full of water.


Heat is set to 180F ( lowest setting) on the boiler.

What can be the issue ? Here is what I think might not be :

Inlet valve ( bell shaped valve by bell and gosset) - it fills to 11-13PSI only....


Do I need to replace the expansion tank? Dont know what to do.
 
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Old 01-16-08, 11:31 AM
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Shut it off! 90 psi is 60 psi over normal residential maximums!!!

You probably have a waterlogged expansion tank but there are bigger issues if the pressure can climb to 90 psi. Please call someone in.
 
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Old 01-16-08, 01:06 PM
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thanks for that, its been off for a while now. I dont think its the expansion tank, as I am the one who took the air out to reduce the pressure.

What else can I check ?

Thanks,
 
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Old 01-16-08, 01:18 PM
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Originally Posted by sunny_8 View Post
thanks for that, its been off for a while now. I dont think its the expansion tank, as I am the one who took the air out to reduce the pressure.

What else can I check ?

Thanks,
You need to put the air back into the expansion tank.

And, more importantly, replace the safety pressure relief valve.

Al.
 
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Old 01-16-08, 01:28 PM
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What about replacing parts ? Where could the problem be ?

Do you think I should shut off the inlet water when the standing pressure is 12-14PSI adn then see what happens ? That should isolate the Inlet pressure vavle right ?

Not sure where to buy them...Home Depot Or Plumbing place ?


thx
 
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Old 01-16-08, 07:02 PM
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Letting the air out of the tank to reduce the pressure was 100% the WRONG thing to do. You made a bad situation worse.

Close the manual fill valve. Open a boiler drain (with a hose on it) and reduce the boiler pressure to ZERO. Put the proper air charge back into the tank. It should be 12-15 PSI . You can NOT check the air charge in the tank with pressure on the boiler. This is the first step. That tank REQUIRES a proper air charge in order to allow the water to expand into the tank and compress that air cushion as the water heats and expands.

After you attain the proper air charge on the tank, open the manual fill valve and allow water into the system to a pressure of 12-15 PSI. CLOSE THE MANUAL FILL VALVE AGAIN.

Next, find your PRESSURE RELIEF VALVE. Look at the pipe coming out and going toward the floor. Did a knucklehead put a cap or plug on that relief valve ? If so, remove the cap or plug.

Your PRESSURE GAUGE _might_ be in error, so you need to verify that. You can go to HD or LOWES and pick up a pressure gauge that will screw onto a hose fitting. Normally used by lawn sprinkler dudes for checking pressures, but works fine for boiler use. Under $10 around here. They have a 0-200 PSI gauge on them, so are not much use for low pressure use because of poor resolution in that range, but it will certainly tell you if you actually have 90 PSI on the boiler. That is a VERY DANGEROUS ! pressure level if it is real. Screw that gauge onto a boiler drain, open the drain, and verify that your boiler pressure gauge is accurate.

I like a phrase that furd used the other day:

"By all that is Holy" ... do NOT operate your boiler at 90 PSI! Your life is in danger ... seriously ...

If you suspect that the pressure reducing valve is at fault, then yes, you can temporarily run the boiler with the manual shut-off closed, but WATCH THE PRESSURE !

I can't stress this enough...
 
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Old 01-17-08, 06:56 AM
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Thanks for the advise. I will do as you state, there is no cap on the pressure relief valve, and I was thinking if the pressure is 90 psi then that thing should have blown no matter how much rust is on it ...right ?

gonna go to HD today and get the gague....

thanks again and will give you an update monday
 
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Old 01-22-08, 11:40 AM
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Update -


Changed the Expansion tank, doing the relief valve on sat. Filled system to 12 psi standing pressure, then closed inlet valve.

Now system runs at about 15-20 PSI all the time.....so I think I am good......thanks all for the help!!!
 
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Old 01-22-08, 04:55 PM
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Great! thanks for letting us know the success!

Good Luck on the relief valve!
 
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Old 02-18-08, 05:50 AM
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Well guys/gals I thought I have it fixed.

So I did what all is said above, and the pressure is now going back to the 40psi mark. The new relief valve opens when its above 35 psi, and there is a lot of air in the system.

I tapped the pressure relief tank, and its about 1/3rd full, but the pressure is still at 35/40psi.

What else can it be ? The incoming cold water is off, air gets in the system some how and the pressure goes up.

I was thinking of replacing the relief tank before getting ripped off by a professional HVAC guy....

Any thoughts what so ever (related to this) please give me a shout.!!


You guys are great !!

Thanks,

Sunny .....
 
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Old 02-18-08, 06:14 AM
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Sorry meant to also ask what a good brand of expansion tank is.....as the last one I got might be bad.

I have a AMTROL EXTROL #30 was thinking bell and gosset..

thanks
 
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Old 02-19-08, 05:46 AM
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******************bump*******************
 
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Old 02-19-08, 10:52 AM
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Pictures of the boiler and piping around the boiler will help us to help you. Be sure to get far enough back to give a general overview of the boiler and piping and also some closer in shots showing the various valves, gauges, pumps and controls.

You can't have too many pictures.

Post the pictures on a photo hosting site (www.villagephotos.com is one I like) and give us the public URL here.
 
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Old 02-26-08, 06:47 AM
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Here are the pics I have

http://www.villagephotos.com/pubbrow...der_id=1971246

Installed a B&G Expansion Tank.

At 170 Degrees right when the burners turn off the pressure reads 25PSI.

I hear water going into the tank and running out of the tank.
Stand still pressure with no heat was 12PSI.

I have the thermostat set to 52 and will see if the relief valve leaks if so then the pressure went above 35PSI.

Hope this helps some....

thanks,
 
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Old 02-26-08, 11:51 AM
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I couldn't see a thing on the pressure/temperature gauge picture but I did notice two things on the rest of the pictures.

The first is that you have LARGE piping in the original system. I'll bet you have large cast iron radiators too. Did you have poor heating on the floor where you removed the radiators? What did you do with the piping after you removed the radiators? Did you simply cap the pipes or did you connect the supply and return lines with new piping?

The second thing I saw in the pictures was that you have installed the new safety valve some distance from the boiler AND with the stem in a horizontal position. This is not the cause of your pressure problem but it is poor practice. The safety valve should always be installed as close to the boiler proper as possible and the stem should always be in a vertical orientation.

I strongly suspect that your pressure gauge is reading at least five psi high if it reads 35 psi when the safety valve opens.

But your REAL problem is that the expansion tank you have is way too small for the amount of water you have in your system. You need to either add another expansion tank or replace the existing one with a larger model.
 
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Old 02-26-08, 12:58 PM
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The area where I removed the rad's I just plugged the pipes. Did nothing more. Each floor had seperate pipes running to each of the large radiators. So I cut one whole floor out.

Expansion tank :

I tap it to see how full it is, and at 170degrees its about 1/3 full. Can it get more full than that ?

If I need to add another, where would I add it ?

Thanks,
 
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Old 02-26-08, 02:01 PM
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Can I put another tank of the same size inline with the current ? I am thinking of making a tee and then adding in another tank of the same size.

Thanks,
 
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Old 02-26-08, 05:39 PM
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Yes, you can use two tanks.

Tapping on the tank isn't really going to tell you much.

Before you install any tank, even brand new, verify that the air charge in the tank is properly set at 12-15 PSI before installing. I know they say they come pre-charged, but don't believe them.

What furd said about the relief valve, plus this:
Don't use galvanized pipe. Use only black iron. The zinc in the galvanized pipe can cause problems with the boiler... something about electrolysis... so get rid of that galvanized.

I don't see any air scoop or air vents ? How are you getting the air out of the system ?
 
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Old 02-26-08, 06:03 PM
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Originally Posted by NJ Trooper View Post
Don't use galvanized pipe. Use only black iron. The zinc in the galvanized pipe can cause problems with the boiler... something about electrolysis... so get rid of that galvanized.
Does glycol ring a bell?
 
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Old 02-27-08, 05:55 AM
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Ok so here is what I did :


I put both tanks on the system. so now I doubled my expansion capacity.

Here is what I saw :

1. The pressue was 25 PSI at 120 Degrees.
Notice that right after I filled the system last week the pressure was 25 PSI at 180 Degrees. The relief valve had let about 5 gals of water out.

This means to me that there is some external introduction of pressure in the system. I have the incoming water turned off.

I was thinking could it be possible that there is a crack in the cast iron tank that heats the water, which would make the water turn to steam and then increase the pressue ? I dont see any visible water under the boiler or anywhere else....

Here is a pic of the newly installed tanks - I have to get rid of the glav pipes...will do that this week.

http://www.villagephotos.com/pubbrow...der_id=1971246
 
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Old 02-27-08, 06:05 AM
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Sorry missed one thing, I get air out by bleeding the rads.
 
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Old 02-27-08, 07:11 AM
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Unless you have glycol antifreeze in your system I don't think galvanized piping is any kind of issue.

Would it be possible for you to hang both tanks instead of leaving them mounted sideways? Mounted as they are, there will be some air trapped near the top of the tank on the normally "wet" side of the diaphram.
 
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Old 02-27-08, 07:20 AM
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WHO -

If this works for a week and the pressure does not go up, then I can change them. I ran out of parts ;-)
 
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Old 02-27-08, 07:28 AM
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No problems... it might be worth it to try and hang them down a bit as well. The more you can do to remove stress from their lives (2 vs 1, some isolation from greater temperature cycling) the better.

Good stuff!
 
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Old 02-27-08, 09:50 AM
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You may still have a problem with pressure. Since you removed radiation you may not but a boiler of that size with cast iron radiation should use a #90 tank according to extrols chart which will be different than B&G's. Tanks are sized according to water volume. That is why I am saying you may be OK as you reduced the volume of water in the system by reducing the radiation load in the home.
 
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Old 02-27-08, 12:12 PM
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Based on the last few posts.

What would make the pressure be 25PSI at 180 Degrees one week and then 25PSI at 120 Degrees the next week ?

I am confused as to where external/new pressure is coming into the system.

As it seems the pressure is increasing I think I will never have enough expansion "space" for water/air/steam.

What do I NOT understand ?

Thanks you guys rock !
 
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Old 02-27-08, 03:42 PM
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Have you replaced the auto feed (PRV)? Drop pressure to about 12 psi and shut off the feeder for about a week and see if the pressure changes. Also when you do this watch the pressure when the boiler heats up and see if your pressure changes. Are you going to do boiler protection. I don't see any in the pic's.
 
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Old 02-28-08, 05:50 AM
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rbeck :

Pics are at : http://www.villagephotos.com/pubbrow...der_id=1971246


I have done the following :

Filled system up, leaving incoming water valve open, and watched it for 3 hrs - only showed 12psi which is good.

I then thurn off the incoming water valve so no more water should enter the system. Pressue still goes up after a week.

Could the steam/crack thing be somthing to consider ?

thanks
 
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Old 02-28-08, 08:24 PM
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Link did not work. Is the valve a stop valve with a washer in or a ball valve. If there is a washer maybe the washer is not shutting off the water. At times they get hard or worn to the point they just don't work. In water systems there are only two ways water gets into the system. The auto feed or domestic water coil. You do not have the latter. Change the washer and see what happens.
The steam thing is not going on. If your thoughts were possible the steam would condense and pressure would drop back down to 12 psi. When the boiler would cool you would have a water leak.
 
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Old 02-29-08, 06:23 AM
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try this : http://www.villagephotos.com/pubbrow...der_id=1971246

The valve for incoming water is a stop valve with a washer. I can try changing it if this still continues. Glad the steam thing is not going on, as I did not want to spend $3K+ for a new boiler or heat system.

Thanks,
 
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Old 03-10-08, 06:51 AM
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so even after having doubled my expansion tank space, some water is coming out of the pressure valve. Less than before but still comes out. When the system is off and temp is about 100 the pressure is now 20PSI.

Anyone have any more ideas ? I was thinking of getting a huge expainsion tank...lol

thanks,
 
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Old 03-11-08, 12:37 AM
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As Who stated, having the expansion tanks horizontal without also suspending them to take stress off of the connection point is poor practice that will eventually cause the tanks to break at the connection point.

There is only one way for the cold pressure to increase and that is from an inflow of fresh make-up water.

It is possible that the "risers" that you disconnected the radiators from are, or at least were, full of air and if you did not install valves to bleed this air they have acted as auxiliary expansion tanks...until the air in them becomes dissolved into the circulating water.

I think that your make-up water system (hand shut-off valve and pressure reducing valve) are slowly leaking through and adding water to the system. It is still possible that you do not have enough expansion tank capacity.
 
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Old 03-13-08, 08:20 PM
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ok what if I put in the expansion tanks upright and hang them correctly. I want to get a bigger one....but dont think it will fit.

How far out can the expansion tank be from the boiler ?

I will add in a ball shut off valve to the incoming water supply and then once the boiler is filled to 12 psi, turn it off...so there is no chance that any water comes in.

do you think that will work ? What is the size of exp. tank you think I would need to add, understanding I will still keep the #30 Bell and Gosset.

Thanks for all the help
 
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Old 03-14-08, 07:23 AM
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I think the farther you can get the ET from the system the better, since it reduces thermal expansion.

I'm pretty sure that both Watts and Amtrol both have sizing calculators on their web sites.
 
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Old 03-15-08, 07:30 PM
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ok, so I have a few cut off pipes in the basement, and I will try and connect up a larger expansion tank there.

Is there any guides on the pipe size ? right now I have both tanks on a 1/2 inch.

I am going to move those out away from the boiler unit too.....

thanks,
 
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Old 03-15-08, 08:18 PM
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Ideally you want the "point of connection" of the expansion tank(s) to be near the suction side of the circulating pump. This will give you the desired "pumping away" configuration.

Looking at the pictures the suction of your circulating pump rises to a T fitting and continues to a union. I suggest that you insert a tee between the first tee and the union and connect your expansion tanks at this point. You can use the full size of pipe (it looks to be one inch) and then use fittings to reduce to the 1/2 inch of the expansion tanks.

I suggest that a valve be installed either in the line that will connect to the tanks OR individual valves to the separate tanks. These valves need to have their handles "locked" in the open position at all times except when actually changing a defective tank. I like to use ball valves and nylon wire ties for locks.
 
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Old 03-16-08, 03:35 PM
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thanks, furd.

Do you think you could mark up one of the pics and show me what you mean ? It would be easier to understand for me.

thanks again!
 
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