Can't get one boiler zone to circulate after bleeding system down - suggestions?

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Old 02-08-14, 01:10 AM
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Question Can't get one boiler zone to circulate after bleeding system down - suggestions?

The cold is biting me in more way than one,

I have a relatively new propane boiler in the basement and base board heat for a two story house with one circulation pump, Spirovent, expansion tank and three zones in my house. Two zones on the main floor and one zone on the second floor.

As propane costs have quadrupled (don't get me started) I tried to shut some doors and turn down the the thermostat in a part of the house we use the least. Bad idea, I froze a pipe in a poorly insulated corner of the house and the pipe splits, system pressure drops, big mess.

As there are some complications to repairing the split pipe and the related mess, I decided to isolate the zone with the split pipe so I can run the other two zones as the temp is about -10F and repairing the split pipe will take some time.

Unfortunately the system didn't have isolation valves for the individual zones, so I had to bleed down the entire system and sweat in a new valve on the return end of the damaged zone loop and rely on a manually closed zone valve on the supply side of the zone to isolate the leaking pipe(zone).

I then re-filled the system and brought it up to pressure (15 psi) everything holds, leaking zone with split pipe is successfully isolated.

Then I have the second floor thermostat call for heat. Zone valve opens, boiler kicks on, circulation pump kicks on and base board on the second floor warms up just as it should. Things are looking up.

Next I have the thermostat for the remaining zone on the main level call for heat. Zone valve opens, circulation pump is running, but none of the baseboard on the main level heats up???


The only logical reason I can think of is an air lock in that zone on the main level, as the other zone on second floor works fine. There are no manual bleeders anywhere in this system to bleed air out of the zones (just the Spirovent at the boiler).

So if in fact I have an air lock in one zone, how do I get the air out and allow the water to circulate?

BTW - I am confident that the pipe for the zone on the main level that will not circulate water is not frozen. Again, there is only one pump for the entire system and it is working.

Any tricks to getting the air out of the zone that will not circulate?

Any potential problems I am overlooking or haven't considered?

Thanks for any suggestions,

GD
 
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Old 02-08-14, 06:49 AM
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There must be a boiler drain somewhere on the system... You will need to take pics of the system so we can see what you have....
 
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Old 02-08-14, 08:50 AM
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GD,
The first thing you mentioned was no isolation valves. From what you said it sounds like your ZV's are on the supply because you added a shut off to the return line to isolate the frozen zone.

First, do you have a loop system, which means your supply for a zone goes from room to room etc. using the baseboard as part of the loop and back to the boiler with the same pipe and the other zone the same way.

If this is the case you don't need individual bleeders. You need a drain valve on your return line but you also need isolation valves on each zone.
You bleed one zone at a time and you have to be able to shut off the other zones to do this.

You must have something somewhere if they bled the system initially.

Is it possible to get some pics of the boiler and piping, especially the return lines and supply where the ZV's are.
 
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Old 02-08-14, 10:36 AM
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Aside from the other's advice...

rely on a manually closed zone valve on the supply side of the zone to isolate the leaking pipe(zone).
I would not rely on a closed zone valve to create a positive seal. They aren't designed for or expected to perform that function. You may have a problem if/when that zone thaws out.
 
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Old 02-08-14, 11:59 AM
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Pics and more info

Hopefully these images come thru.

This how I understand the system to be configured
:

#1. Coming out of the top of the Weil-Mclain CGa boiler is what I assume to be the boiler output with a Pressure and Temp Gauge>

#2. Next in line is the SpiroVent and Expansion Tank>

#3. Next is a Inline 1" Ball Valve with an orange handle>

#4. Next the pipe branches off to the 4 different zones running thru a Series of Baseboard Radiators (I may have initially stated there are 3 zone, I don't use the zone in the basement so I originally omitted that one)>

#5. After passing thru the baseboard Radiators, the circulating water returns to 4 Individual Zone Valves>

#6. Below the zone valves are 4 Individual Bib/Spigot Bleeder Valves with red handles (which I think are for bleeding the individual zones)>

#7. After the bib valves the four pipes converge into a Single 1" Copper Pipe>

#8. The Single 1" Copper Pipe runs back over to the boiler and there is a Bib/Spigot Bleeder Valve with a blue handle>

#9. After the bleeder second Inline 1" Ball Valve with an orange handle>

#10. Below the ball valve is the Taco Circulation Pump>

#11. Below the circulation pump is another Bib/Spigot Bleeder Valve>

12. Last the pipe returns into the side of the Boiler.

Note: On this boiler, what I call the "make-up water supply is fed into the top of the boiler.


So here is what I tried doing with the zone that I think has an "airlock" and and needs to be bled or purged:

A) System pressurized and the furnace and circulation pump off.

B) Open only the one zone valve for the zone I am trying to purge/bleed.

C) Shut off 1" ball valve above (#9) above circulation pump.

D) Opened the bib/spigot bleeder valve below the zone valve for the individual zone that won't heat up.

E) Open the make-up/supply water valve to increase pressure and try to push fresh supply water through the only zone that is open - from the boiler, thru the zone baseboard radiators, thru the zone valve and theoretically out the bib/spigot bleeder under the zone valve - as the water/air should not have any place else to go because of closing valve #9...

Water trickles out the open spigot bleeder below the zone valve for a bit and then nothing. I only ran the pressure up to about 40 psi. - should I run the pressure higher?

I would think that if nothing else water would come out of the open spigot and the system pressure would drop - but it doesn't...

I have tried a few other things but it would be an even longer post.

So - now that you have a few pics, a description of how I think it works, I what I have tried, what am I doing wrong?

Thanks for any insight,

GD
 
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Old 02-08-14, 12:03 PM
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Trying again to attach images...
 
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Old 02-08-14, 12:25 PM
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ran the pressure up to about 40 psi.
Are you sure you aren't reading the "FEET" scaling? If you ran pressure to 40 PSI your relief valve would be blowing. Either that or your gauge is defective.

40 FEET = about 17-18 PSI, check gauge again.

I need to look again at your process, but my initial thought is that you've got another zone frozen.

Just went through it again and from what I can see you are doing it right, and that means bad news, sorry.
 
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Old 02-08-14, 12:35 PM
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GD,
first, you said you went to 40 lbs. Did your relief valve let go. It goes off at 30, or is suppose to. You might want to check your gauge and your relief valve to make sure its working.

Getting back to bleeding. From your description and pics you're doing everything right. I think the initial water you got was from the 1" return.
In theory the water has no where else to go and should come out the spigot if the zone valve is open.

I hate to be the bearer of bad news but if you're positive the ZV is open and your pressure is up, is it possible to have another frozen pipe in that zone.
What you can try is to bleed the other zone and make sure you do have good pressure. If you can bleed the other zone then you've got an obstruction in that zone and since it was working before, I would look for ice.

If you still can't bleed it, you can get the good zone working and put the other zone valve on manual and when the good zone calls for heat it will run through both until its cleared.

Good Luck,
 
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Old 02-08-14, 03:40 PM
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Spott/Trooper,

RE: Did I really run pressure up to 40 psi? The gauge has small print and I need reading glasses so I am not certain of the exact pressure, but the relief valve started dripping and I immediately let some pressure out of the bib on the side of the boiler...

RE: Am I positive the ZV is open? Don't know how I could be wrong, these White-Rodgers 1311 ZV have a rather large visible dial which expose a red mark when the valve is open (other wise it the red mark is hidden behind the ZV housing)

RE: Could another frozen pipe be the reason it won't bleed? Frankly it is the only thing that I can think of. But it doesn't make a lot of sense either. That zone runs through sort of a great room area and an adjacent entry, they have always been in the mid 60's since this problem started - I have a rather large fireplace insert that I have kept stoked 24/7 since my problem started. I have a thermometer in the coldest corner of the basement and haven't seen it below 40*.

RE: Try purging the zone that is functioning properly with the same approach - I just went and tried it and the working second floor zone purged just fine... I guess it is time to go put some serious heat in the basement and use a heat gun where the pipes come closest to the rim joist... I must have a frozen section of pipe somewhere - there are 5 spots with the highest probability where they jump up to a section of baseboard - at least I don't see any leaks.

Thanks for all the feedback,

GD
 
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Old 02-09-14, 01:49 PM
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Thanks to everyone who gave me suggestions, ideas and feedback - the zone now circulates properly.

I ran a couple heaters in the basement yesterday and overnight. Turned it on this morning and it works fine again. I must have had a frozen pipe in the basement somewhere. So now two of the three zones work - enough to heat the house along with the wood burner.

--------------------------------------------------------------------------

The problem remains I still have one zone that I isolated because of a split pipe (see attached image). The pipe froze because of closing off a small room with lots of windows. My fault but now I have to fix it, but what is an acceptable way to fix it? Basically repair or replace:

Option 1: I could repair the split by dismantling the baseboard far enough to splice in a section of pipe where the split is.

Option 2: Some people would suggest that because it was cold enough to freeze in the corner both sections of baseboard in that room are compromised (i.e. potential for failure at a later date), maybe damaged where I can't see it behind the radiator fins and should be replaced.

There are two sections of baseboard in this room one is 6' 10" and the other is 5' 8". The longer section of baseboard is easily accessible, the shorter one with the split on the end goes behind a large cabinet that is very heavy and full of stuff, thus I can't even inspect the whole length of the shorter section of baseboard without spending a day removing it... (see attached image)

So what do you think likelihood is that there could be another split I can't see or that is compromised to a point that could fail at a later time?

One last question - I have a number of sections of baseboard that I pulled out of three season porch that was like new. So are the dimensions of residential baseboard radiators standard? Can I cut an 8' section of the reclaimed baseboard I have down to the lengths I need?

Thoughts?

Thanks,

GD
 
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Old 02-09-14, 02:18 PM
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Hello.

What you do is take a tin snips and remove some fins by the split...Just snip a split in a fin then grab it with the snips and twist... They come right off... its a learned thing from doing it often....


Then cut a clean area just past the split... Unsweat the split pipe out of the ell... Then coupling, new piece of pipe to the ell...

I reuse the ell thats there but I been doing it a long time.. possibly you want to replace the ell?? If so you need to unsweat it...

Clean joints good. Use cleaning brush, emery, etc... get the brown flux and not the white crap from the big box store....

Do you have more???

Just look at all the corner ells and mid way at the BB where the low spots are is often the additional areas....
 
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Old 02-09-14, 03:10 PM
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GD,
As far as your spare baseboard, you would have to measure the fins and the enclosure if you're going to mix & match.
If replacing all it's fine. The heat value is fairly standard.

Are for changing everything and future leaks, there is really no way to tell unless you look at the pipes and see if they've been compromised.

What I would do because of the amount of work involved and maybe needlessly is to repair the split but I would cut the whole elbow out on both sides and far enough back. Clean the pipe and put in a new elbow and pipe and 2 slip couplings. The slip couplings have no stops and slide right over pipe. Install elbow with new pipe and slide couplings back to join pipe. You can pre solder elbow and pipe and then just solder couplings to finish.

If your leary and you solder, you can add a shrader valve where accessable and test with air first. Let sit overnight to make sure.

Good Luck,
 
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Old 02-09-14, 04:25 PM
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Thanks for the insight Guys,

I have never heard of a slip coupling, slick idea, it will make the repair easier in that tight corner!

Yes, I can solder. If I added a Shrader Valve to test with air, I am assuming I would have to remove it before refilling with water?

Any tricks to "unsweating" joints? I have done it before, but old joints like this seem to be stubborn and take lots of heat... Any tips or tricks?

Thanks Again,

GD
 
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Old 02-09-14, 04:26 PM
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I think a good tip is:

BEFORE you cut out the bad section, use your plumbers sandpaper strip to PRE-CLEAN THE PIPE FIRST, this way once the pipe is cut, it's already clean, all it will need is a bit of de-burring and some touch up cleaning without having to wrestle with a loose piece of pipe flopping around.
 
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Old 02-09-14, 05:55 PM
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Thanks for the tip Trooper - Good idea!
 
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Old 02-09-14, 05:56 PM
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If you cut the elbow right out you won't have to unsolder. Cut 6" back on both sides of the el and give yourself room to work. Make up the 90 with the two pipes on a bench and solder so your not working in the corner. With the slip couplings you don't deduct for the fittings. You measure your pipe end to end and just slip the coupling over the ends and solder.

Install a 3/4 C x whatever size Schrader and then remove valve & put in brass plug.
 
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Old 02-09-14, 06:30 PM
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You guys are Great!

I really appreciate the help/wisdom!

 
 

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