Need some basic help from the pros/ purge air and refill


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Old 10-10-13, 07:32 PM
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Need some basic help from the pros/ purge air and refill

Gentlemen,

My parents need my help with their oil burning boiler heating system, I have a diagram I made from when I serviced the system last year, which consisted of priming the system, replacing the filter and making sure zone valves worked and heat worked. I need to get to them as they have reported a loss of heat, cold rooms towards the end of the pipe run so I believe the lines need sediment or air flushed.

The system is copper pipe with fins, there are no bleeder valves on the baseboard. They have two zones. The new oil company offered maintenance but will not bleed the system. If you can help from my picture that would be great. Pics would have to wait until I am there, and I hope it is easy enough that someone can help us out before that so I can get them up and running. the baseboard is hot and cools the further away you get from the zone valve. Does that sound like air or a pump issue? Thank you in advance, we'd prefer to hire a pro but can't right now.

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Old 10-10-13, 07:44 PM
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Can you make your pic bigger?

It may be air and you could possibly purge the system... But why is there air? Your air vents on the system may be faulty and new introduced water is causing the air issue. ( You would be losing water)

Or you could have low pressure in the boiler. If not enough pressure the circulator will not move water to the higher zones. (Fill valve closed and you could be losing water)

You have heat in one zone so the circ most likely is working. Possibly a zone valve...
Or even a t stat bad. ( Batterys?)

A bigger pic will help because my old eyes at 47 cant see well and mywalmart glasses dont help
 
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Old 10-10-13, 07:50 PM
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Unfortunately, because the forum re-sizes photos, the text in your graphic is pretty much unreadable. I can make some out but not all.

There's a zone in the basement, and a zone on the first floor... and it's a ranch style, no second floor?

Let me ask about the system pressure... what is the pressure when the system is cold, and when it is hot? This might have some bearing on why air (if it is air that's impeding the heat flow) is building up in the zones.

my old eyes at 47
Jeeze... just a KID!
 
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Old 10-11-13, 06:08 AM
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Hey guys, thanks so much for taking the time to help me! I have attached the picture, I hope that helps. I am sorry it did resize to tiny font on me. Please look at this: http://i.imgur.com/tO21S8T.png?1 or try this :bigger pic

I never thought about the potential problems you pros are bringing up, which is WHY the system loses heat farther down the line. or what is causing the air pockets, if that is the problem. I have read that a purge is good maintenance to pressurize the system so I thought that is where I should start. Edited to say: The system has not been purged that I know of, if that helps.


So to try to answer any questions raised:
  • They have a Ranch style older home 2 zone heat
  • System pressure gauge on front of boiler stays around 16 cold or hot, (I think, I'm going off a phone call)
  • Faulty air vents, need help to locate those. They are not on the copper pipes.
  • Fill valve is a trickle fill/ fast fill reducing valve and no water seen dripping.
  • Zone Valves tests, If they move them to "open" I believe the water circulates all through and the house gets real hot. If they leave them automatic, they seem to work because the piping gets hot after the ZV but that hot water doesn't travel all the way through. Weird.

I hope that helps. I'll be there this weekend to try to do something!
 
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Old 10-11-13, 07:05 AM
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pressure gauge on front of boiler stays around 16 cold or hot
This would cause me to be HIGHLY suspicious of the gauge accuracy. It SHOULD change from cold to hot... at least a few PSI... if it doesn't ever move, the chances are that it is not functional and that you could have low pressure in the system which would aggravate an issue with air.

Those drain valves on the return lines... is there an actual drain with a shutoff valve in line with it?

If unsure, can you photo this area?
 
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Old 10-11-13, 02:19 PM
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Hi NJ Trooper,

Yes, those have a hose fitting and spicket. The other drain valve next to the combustion chamber(lower right of the furnace) also has a spicket and hose fitting as well where the water re-enters the boiler.

The 3 return line valves had brass covers on them, but unscrew those and I could attach a garden hose to it.

I will tell them to set the thermostat to off in the morning so I can see the PSI reading for myself.

Thanks for your help!
 
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Old 10-11-13, 02:52 PM
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I'm not sure I explained what I was saying well...

In this graphic, note that the bottom picture has a STOP, or SHUTOFF valve in series with the actual hose bib drain valve.



In the top part, if you try to 'purge' air from the zone, you won't be successful because the water will just run through the boiler and out the drain.

The bottom part, you can see that by closing that stop valve you prevent this and the water MUST travel through the zone.

I'm working toward the actual purge process here...

So, do you have TWO valves at each of those locations? One is the hose bib drain, and the other should be a STOP or SHUTOFF valve. Can you photo that location?
 
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Old 10-11-13, 03:04 PM
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Let me collect this thread into a series of steps...

1. First you need to verify if you have adequate pressure in the system. This is where verifying the pressure gauge comes in.

Read this: http://www.doityourself.com/forum/bo...ure-gauge.html for help with that.

2. In order to avoid future problems... preventative maintenance... you should check and charge the expansion tank with air as needed.

Read this: http://www.doityourself.com/forum/bo...sion-tank.html for more help with that. Note that this thread has a STEP BY STEP instruction for properly re-charging the Extrol tank.

3. PURGE AIR from the zones using the valves mentioned in previous post. We will help you with the process once we know that you have the proper valves to do so.

4. Re-pressurize system and check that the PRESSURE REDUCING VALVE (You've called this a 'fast fill' in your diagram) is functioning properly.
 
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Old 10-11-13, 05:54 PM
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NJ Trooper,

I will need to stop and grab a gauge on my way out to read pressure, that setup is a great idea. Please look at this and click to enlarge: Better Diagram?
Does that help define the water lines and stop valves? I definitely plan on taking pictures when I am there.

I have studied your diagram and it makes perfect sense - in my situation it appears I would need to purge the entire system through the furnace. The way this one is designed, I don't see what purpose the shutoff valves serve besides servicing components or if the thing starts gushing water .
My original wrong idea on the system purge:
  1. System off and cooled down
  2. Open both zone valves
  3. Open the main drain valve at the very end of the return line and let it gurgle and spit, sediment, rocks, until I see clear water for a few minutes. The system loses pressure at this point?
  4. Throw the lever on the pressure reducing fill valve to open up water flow
  5. Close the main drain valve
  6. I am guessing at this point the system should start building pressure
  7. Close the pressure reducing valve at 16psi.
However, your pro advice sounds like I should bleed each zone:
  1. System off and cooled down
  2. Open both zone valves
  3. Shut off supply line
  4. Open the basement Zone 2 drain valve and let it gurgle and spit, sediment, rocks, until I see clear water for a few minutes and close.The system loses pressure at this point and goes to zero
  5. Repeat for Zone 1A and Zone 1B
  6. check/ charge the expansion tank using your instructions
  7. Open the supply line
  8. Throw the lever on the pressure reducing fill valve
  9. I am guessing at this point the system should start building pressure
  10. Close the pressure reducing valve at 16psi.

Am I onto it or am I confused? I bet you have installed some really amazing systems. Thank you for your help.
 
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Old 10-11-13, 07:23 PM
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I liked your first drawing better BTW!

Am I onto it or am I confused?
Confused I'm afraid...

In order to 'purge' a system, you don't want to DRAIN anything... The only draining that you will do is the little bit of water you need to let out in order to drop the pressure to charge the expansion tank.

The idea is to push water UNDER PRESSURE through the zones, one at a time. The water is what is going to push the air out.

Just opening a drain is only going to let more air INTO the system!

At this point you still haven't answered my question about the 3 zone drains.

Are there, or are there not, a shutoff valve on the pipe immediately next to the three zone drains?

Possibly you aren't answering because you aren't there and aren't sure?
 
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Old 10-11-13, 07:36 PM
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Some systems have 'purge valves' that look like this:



The top part is of course the drain, but you see that 'knob' sticking out just below? That is a shutoff valve that is turned with a screwdriver. Maybe this is what you have and just didn't notice the other part?

Then there's the ones that have TWO separate valves like this:



The yellow handle valve is the shut off and the blue handle is the hose drain.

These are examples of what you need to look for when you go...

There IS a workaround if you don't have this... not quite as effective, but should get the job done.
 
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Old 10-11-13, 08:03 PM
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HI NJ Trooper,

You are right! I had to really read my notes, but found possibly what you are looking for on the drain valves.

I mapped the system, and there are no shut off valves on the return lines until the STOP before the circulator, because I would have drawn them in. Now you did get me thinking and I realize why you like pictures, because I wrote down that there were inline isolation valves past each of the three hose bibs.

isolating valve

I am now researching these, I had them written down as straight screwdriver coupler. I hope this helps.

*Edit: Saw your follow up post and you nailed it, it's not one piece, but same functionality.
 
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Old 10-12-13, 08:30 AM
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I hope this helps.
Yes, very much so.

There is another prerequisite that should be looked at:

On top of the Taco Air Scoop, there is a Maid-O-Mist automatic air vent. The small cap on top of this vent must be LOOSE so that trapped air can escape. When this cap is loose, there should be NO WATER LEAKAGE (you may get a few drops along with air, but no CONTINUOUS leakage). If there is continuous leakage, this vent valve should be replaced. When you have the system pressured down to check the expansion tank is a good time to do so if necessary.

I wrote down that there were inline isolation valves past each of the three hose bibs.
When you say "...past each of the three hose bibs...", you mean on the BOILER SIDE, closer to the BOILER, or DOWNSTREAM of the hose bibs... (this is the way it should be, just want to check and make sure!)

OK then, let's continue...

Once we know that there is an accurate way to measure the system pressure, we can proceed. This is the FIRST step.

Next, follow the step by step instructions for charging the expansion tank properly in the previous linked message... copied here for easier reference:

=============================================

1. Shut off boiler and allow to cool to under 100F.

2. Shut off water supply line to boiler.

3. Drain only enough water from the boiler drain (note: this does not have to be THE boiler drain. It can be ANY drain valve on the system. Use the one that is most likely to be able to not leak when closed again!) to drop the system pressure to ZERO. REPEAT: DO NOT COMPLETELY DRAIN THE BOILER! ONLY ENOUGH TO DROP THE PRESSURE TO ZERO!

4. With an ACCURATE tire pressure gauge, check the air charge in the tank on the air valve opposite the end of the tank that's connected to the system. If ANY water comes out of the air valve, the bladder inside the tank is shot and the tank needs replaced. If no water comes out the air valve, and the pressure is less than 12-15 PSI, continue to step 5. If the pressure is OK, turn the water supply to the boiler back on and re-pressurize the system, turn the power back on to the boiler, no service is necessary.

5. Using a bicycle pump, or a small air compressor, add air to the tank until you have 12 PSI air charge.

6. Check the boiler pressure gauge again, and if it has risen off ZERO, drain some more water from the boiler drain until it is again at ZERO.

7. Check the air charge on the tank again. If it is below 12 PSI, add air to the tank until it is at 12 PSI.

8. Repeat steps 6 and 7 until the boiler stays at ZERO and the tank stays at 12 PSI. At this point, the tank is properly recharged and the water supply can be turned on to re-pressurize the system (to between 12 and 15 PSI), turn the power on to boiler and return to service.

=============================================

Once this step is complete:

Now we may need to purge the zones if there is air trapped in them preventing proper flow of water. An air bubble in a zone is as good as a cork in stopping water flow.

You are going to do each zone, one at a time... again, with the boiler OFF and COOL as above, with the water feed to the boiler OPEN so water may enter:

1. Close all three of the 'inline isolation valves' such that the screwdriver slot is perpendicular to the pipe. These are 1/4 turn valves. They are OPEN when the screwdriver slot is parallel to the pipe, and closed when perpendicular.

2. Connect a drain hose to one of the zone drain valves (start with the basement zone, the lowest one) and route to bucket or a laundry tub so that you can keep the end of the hose underwater and are able to observe air bubbles from the end of the hose. If using a bucket, you obviously will need a floor drain or sump pit, or have the bucket outside with a helper observing for bubbles. MANUALLY OPEN the respective ZONE VALVE and put the lever under the 'tab' to hold the valve OPEN. Leave the other one closed.

3. OPEN the drain valve with the hose. Water should discharge from the system into the bucket or tub. You should hear water feeding through the 'pressure reducing valve' into the system. This water will flow into the boiler, up through the zone, and out the drain.

4. Your 'pressure reducing valve' should have a 'lever' on it. This is called the FAST FILL lever. When you lift this lever the pressure regulating feature of the valve is bypassed and water can flow into the system at a higher rate. Lift this lever and allow water to come in fast... observing the bubbles from the hose, continue until there are no more bubbles. Keep an eye on the pressure gauge when you lift this lever. If you see it approach 25-27 PSI, release the lever for a moment to allow the pressure to drop again... if you let it go above 30 PSI, the safety RELIEF valve will open and spew water. You may be able to 'regulate' the pressure manually by holding the lever partially open...

5. Once no more bubbles are exiting the hose, RELEASE THE FAST FILL LEVER, and then close the drain valve. (In this order... fast fill first, THEN close drain)

6. Move the drain hose to the next zone and repeat this process for each of the three drains.

7. When finished, OPEN the three 'inline isolation valves' and return the zone valves to the AUTO position. The pressure reducing valve should AUTOMATICALLY re-pressurize the boiler to the correct 12-15 PSI. If there is a problem with this valve, it may continue to slowly feed water and increase the pressure in the boiler. If this happens, it should be replaced... but the immediate solution is to close the manual feed valve temporarily. The system CAN BE RUN with the manual feed valve closed, but someone needs to do due diligence in observing the pressure gauge on the boiler in this case. It should NOT drop... but it MAY... because:

Fresh water contains massive amounts of dissolved air. When the boiler heats up, this dissolved air will be driven out of the water and vented to the atmosphere by the automatic air vent. As air is vented, the volume in the system is decreased, and the pressure will likewise decrease. More water will need to be added to the system to bring the pressure back up again.

At this point, you have:

1. Checked for proper operation of the automatic air vent.

2. Properly recharged the expansion tank.

3. Purged all zones of trapped air.

4. Re-pressurized the system to the correct cold fill pressure.

5. Checked the pressure reducing valve to be certain it will not over pressurize the system.

6. Placed all valves in proper operating position.

And you are ready to fire up the boiler and test.

There's a lot here to digest... but please read it through and understand what you will be doing before you start...
 

Last edited by NJT; 10-12-13 at 07:03 PM.
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Old 10-12-13, 10:23 PM
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Thank you Thank you Thank you Thank you

NJ Trooper,

Thank you for taking the time to help. There is a lot of misinformation out there regarding simple maintenance of these systems I believe, a lot of assumptions that a novice would not know, and I just can't afford a pro right now.

So, I was not able to do anything today, the system was left on (too many t-stats), so I took care of the yard and opened the basement zone for now. They will be warm.

Your information is crystal clear, and I understand. I will cut a cheap-o garden hose to make the pressure gauge and use the other end to bleed air into a trash can.

I am glad that it seems you enjoy what you do and grateful for your enthusiasm as a teacher, it will help my parents a lot and that really helps me. I think this will be a success on my next visit, which is ASAP, unless there are other problems, which I will have pics for.

Thanks again and enjoy your weekend!
 
 

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