draining & refilling system with no bleeders

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Old 12-20-10, 11:26 AM
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draining & refilling system with no bleeders

From an earlier post I understand I need to flush my system. It has a very weak solution of glycol that has been in the system for 2-3 years. I am going to refill with only water as the glycol is not needed. I plan to also check the expansion tank for the proper pressure (12-15#) when all is empty. My system has 6 zones including the indirect water heater. The highest zone is about 22 feet above the boiler. The system does not have any bleeder valves on any of the zones. It has a Taco air scoop with the expansion tank below it. There is a valve at the end of the bypass loop that I can leave open when I refill. My question is how to refill and bleed the system. What do I do to be sure I get water all the way up to the highest zone?

Thanks
 
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Old 12-20-10, 12:15 PM
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If you take pics of your set up that would be great.I would say you have 6 zone valves and 1 circulator. Below depends on where your zone valves, isolation valves, and drain valves are. Every system is different. You might have one isolation valve and one drain and need to open individual zone valves for purging.

Like I said all systems are different.

1. Shut the isolation valves for all the zones on the return side and supply side.
2. Turn power off to boiler and circulation pumps.
3. Working only one zone at a time, do the following:
a. open the isolation valve on the supply side for the zone.
b. put a hose on the correct drain and put end into bucket
c. open drain thereby letting water into bucket
d. open fast-fill valve (actually lever), keeping an eye on the boiler pressure gauge to make sure it doesn't exceed 30 PSI.
e. fill bucket until no more air bubbles come out.


You will also need to just flush the boiler itsself. Close all isolation valves and drain from boiler drain.


You may want to test you expasion tank first. NJ trooper just posted on how to test this but I cant find it. I will look and repost the link. You want to test with no pressure on the boiler and put an airguge at the shrader valve to verify 12 psi.



Mike NJ
 
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Old 12-20-10, 12:36 PM
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Silly me, I do not see where I add pictures. How is this done?
 
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Old 12-20-10, 01:02 PM
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Old 12-20-10, 03:05 PM
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system pic

Hopefully, there are 3 pictures following.




One picture shows a drain valve to the left of the blue storage tank. One is of the whole system, messy. The last pic is of another drain valve just above the Taco air purge. Hope these help, but am doubting it.
 

Last edited by jeweler; 12-20-10 at 03:27 PM.
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Old 12-20-10, 03:28 PM
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OK I see the pics and thats a mess. I see 5 zones out of the 6 you mention.

I do see three valves at the zone valve but no drains... Could you take better pics???

Is that a valve at the pressure gauge going into the boiler? It looks like we may be able to isolate the boiler there and then drain each zone at the drain on the boiler.

Let us know.
 

Last edited by lawrosa; 12-20-10 at 03:50 PM.
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Old 12-20-10, 03:42 PM
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Finally got the pics posted. Don't know if you can tell but there are not enough isolation valves. Can't isolate the expansion tank, or the boiler, nor each zone individually. Only 3 of the 6 zones have a manual shut off valve in addition to the automatic zone valve. And these are placed next to the zone valves. So I don't understand how I will be able to isolated each zone, then the boiler to do the drain and refill for each individually.

Can I just do a whole system drain and refill? Will that top most zone get filled? That one has only the auto zone valve. Seems like this one will drain but not refill since I cannot isolate it.
 
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Old 12-20-10, 03:47 PM
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I noticed some problems in your pix. The green Taco pump is mounted wrong. The motor should be horizontal, or else it will fail prematurely.

See the automatic air eliminator mounted on the air separator above the gray expansion tank? Evidently it has been leaking based on the rust on the pipe below. And make sure the green valve cap on the auto air eliminator isn't screwed down tight - otherwise, it won't work.

It looks like you've got 120-V wiring dangling all over the place - that needs to be in conduit or greenfield. Call an electrician.

What's the make and model of the boiler?

The system's arrangement seems very cramped, probably making access for maintenace difficult.
 
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Old 12-20-10, 04:25 PM
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Tell me what you want to see in the picture. Just better pics does not tell me what to shoot specifically. The air purge was replaced 1 or 2 years ago. The rust is from the old one. This one works. The circ pump was mounted 15 years ago and is still going. I will wait till it fails to change to correct angle. There are no valves at input or output of the boiler. The yellow item is the info tag on the pressure relief valve. All the 120 volt wire was there when this was originally inspected and okayed by the county, 15+ years ago. The system looks a mess but is easily serviced. I don't know about adding all the extra valves though. That might be difficult.

I don't really want to rework a system that has been working for 15 years unless there is a problem. Then it makes sense to make the mods necessary to make it easier to drain. If it ain't broke...

Now that I think about it, I don't know the system has ever been totally drained. It originally had 2 zones with manual shut off valves plus the indirect water heater with no manual shut off valve. Then a zone was added about 4 years later. I assume he just opened or drained the system enough to add the zone. Then about 9 years after that two more zones were added. Those last two are the ones without manual valves. But they are also the ones with the longest runs and the one that is 22' above the boiler. So I am guessing there must be a way to get the water into this zone.

The boiler is a Teledyne Laars Mini Term II 100,000 BTU induced draft on natural gas. Originally for propane then converted.
 
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Old 12-20-10, 04:25 PM
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MORE LIGHT! BIGGER!

Here's a link to the album so when the bigger pics are posted, we can view them full size.

Pictures by 931tcg - Photobucket
 
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Old 12-21-10, 09:07 AM
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summary

First, a correction, the last zone with the longest loop is 14' in height above the boiler, not the 22' stated earlier. This loop has only an auto zone valve, no other shut off valves. Also, one zone has the baseboard radiation unit about 3' below the boiler. However, the supply and return lines are above the boiler about 3'.

Summary
There are 5 zones plus an indirect water heater (6 zones total). Only one zone has manual shut off valves on both ends (supply and return). This is the one that has the baseboard below the boiler. Two zones have only the auto zone valve. The other 3 zones have a manual shut off on the return side only. There is one manual shut off valve on the supply just after the flow switch. There are two drain valves. One is located on the return loop (shown in the photo just above the Taco circ pump). The second is shown on the photo with the large blue drinking water pressure storage tank. I do not understand why there are the two of these as they do not seem to be able to be separated by any valves. And, there is a drain valve on the bottom of the boiler.

If I am to drain and refill the entire system, it appears that I need to do it all at once as I cannot isolate the individual zones. If I turn off the boiler (let it cool), power, turn off the make up water supply, open all the zones, and open the 3 drains, will this completely empty the entire system? Then to refill can I close the boiler drain and one other drain and refill? Will the water get to all the zones? Or, do I shut all the zone valves and fill the boiler and loop, then open and fill one zone, close it and go on to the next?

I am confused because Lawrosa's directions assumed I had isolation valves on each zone. Or, should I just follow his directions ignoring the supply side isolation valves? Will the water stay in each zone without this valve?

Sorry to make this sound more complicated than it may be. Just don't want to do something stupid. Thanks to all for the assistance.
 
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Old 12-21-10, 02:50 PM
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Your zone valves will isolate each zone. If there is no call for heat at any zone they are closed. We want to open one at a time individually and push the water through each zone and out a drain. But we need to isolate where the fill water comes in so it goes around the zone and out the drain, not just out the drain.

I see the drain valve above the circ and a blue isolation valve left of that. We need better pics there to see how that area is connected to the boiler. You may be able to bleed there and open on zone at a time. But not if the make up water it just going to come in and go right out the drain valve.

I see the other drain by your hot water tank, with the read handle isolation valve. Same there as stated above

I also see a valve in the off position just below the fan in the background in the one pic. Where does that go and why is it off?

Or either one of these may be able to isolate one side and you can drain at the boiler.

What will happen if you do what you say in your post is you will have air in your zones and not be able to bleed them. Isnt that what we are trying to do here? You might not want to try that, especially if its cold out and you need heat. You never know what can happen.

Better pics of these areas and where the pipes lead.

Mike NJ
 

Last edited by lawrosa; 12-21-10 at 03:16 PM.
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Old 12-21-10, 04:57 PM
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Mike NJ I do not seem to be able to get better pictures. The widest angle close-up does no better than my previous post. I cannot get far enough away to show more than a small portion of the system.

The drain valve you see above the circ pump is the one I cannot make sense of, other than it was the one used to pump glycol into the system. Otherwise I cannot find a use for it. If I open that valve as a bleeder then the water can go backwards through the system easier than it can go forward and fill a zone. The red isolation valve you see next to the hot water tank is for one of the zones. It will not assist in refilling any other zone. The red valve handle you see near the fan is the blend valve for the bypass. It is not completely closed, only open a small bit. This is adjusted to get the return water to the boiler input to be no more 20 degrees cooler than the outlet water.

However, I am starting to get it. I understand what you are saying about trying to refill and merely running the water straight to the drain before forcing it into a loop. The water will take the path of least resistance. If it can go to the drain valve without going through the opened zone (which is a longer path) it will.

It looks as though I can force the water to go through each zone (one at a time) if it fills by going backward. Meaning the water goes into the boiler outlet, through the boiler, then through the opened zone valve, and out the opened drain valve (the one next to the blue fresh water pressure/storage tank). I can make it flow this direction if I close the shut off just after the flow valve (this is the blue handled valve that says "NIBCO"), the bypass loop blend valve, and the second drain valve (in the picture the one shown just above the Taco circ pump), and open the the other drain valve located by the blue fresh water pressure/storage tank. Then the make-up supply water would be forced to fill the boiler and individual zones going BACKWARDS. This is assuming there are no back flow preventers in the air scoop or boiler or zone valves, or anywhere else in the system. This forces it to fill the loop completely and then out this drain until I get rid of the air bubbles. Then I can, one by one, open each zone valve and fill that zone and run out the drain valve until all the air is gone. Then go to the next zone.

This appears to be the only way to refill each zone individually. Is there a reason why I cannot or should not do it this way?

Thanks
 
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Old 12-22-10, 08:56 AM
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think I have a simple solution

A private message has offered what looks to be the solution. Please advise if there is any problem with this.

I can flush and refill the system, one zone at a time if I close the make up water supply, close the valve just after the circulation pump, temporarily connect a water supply to the drain valve just before all the zone feeds, and open the drain on the bottom of the boiler. This will send the water directly to each zone in the proper direction, back to the boiler, and out the boiler drain. I can lose the supply and boiler drain as the water clears. Then on to the next zone.

This sure sounds like how it is supposed to be done. Any comments?

Thanks again for all the help
 
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Old 12-27-10, 10:56 PM
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Just a word of caution. A friend of mine who is the heating business told me that if you are flushing your system to remove any air locks or your typical clanging noise due to air in the zone, make sure you allow the boiler to cool a bit before you introduce cold (55 degree) water directly from the supply. This will prevent any abrupt temperature change at the exchanger in your boiler reducing the possibility of cracking any cast or other parts. Just my two cents on this topic.
 
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Old 12-28-10, 08:37 AM
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system schematic

http://i245.photobucket.com/albums/g...g/File0883.jpg

Hopefully the system schematic is pictured. None of the zones have bleeders. All valves are shown. I understand there should be several more, but not there.

Does my last post explaining how I intend to drain and refill and purge one zone at a time make sense?

I understand the boiler needs to be cold.

Feedback?



One of these should be a link to better photos.
 
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Old 12-28-10, 09:53 AM
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Make sure boiler is off and cool.

Close valves in red and drain from green. Increase pressure to about 25 psi and open one zone at a time manually.



Mike NJ
 
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Old 12-28-10, 10:04 AM
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drain and fill backward?

Mike NJ If I understand correctly you are suggesting I refill from the make up water supply backward through the boiler? This is what I was originally planning. There is a pressure limit on this supply of 12-15 # per the valve. Will this still work?
 
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Old 12-28-10, 10:15 AM
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There is a handle at the end of the fill valve. Lift up on this. It will fill the boiler to a higher pressure. Dont go past 30psi or the relief valve may open and when your done with all the zones make sure the pressure settles back to the 12-15 psi
 
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Old 12-28-10, 10:25 AM
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That will work... Thank you
 
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Old 12-29-10, 05:44 AM
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If your pressure relief valve sticks up the water going pass it will allow air to migrate up in the relief valve and you can vent that air out by carefully lifting up on the handle. It will take a period of time to do this, though.
 
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