Where To Install Automatic Air Vents

[velvetfoot]

I'm having a devil of a time getting air out of the zones. There two floors and no bleed valves now in the baseboards. I want to put some automatic air vents on my zone piping. I want to limit to one to a floor because of the hassle. Where is the best place in the circuit to put them?

I'm not even certain how the pipe runs upstairs, but if it's like I suspect, the last baseboard on the circuit is in a walk-in closet that wouldn't exactly be closely monitored for leaks, as well as more of a hassle to install. The place I'm thinking of is in a bathroom, but I
THINK it's the first in the circuit.

I'm trying to think this through as well as not burn the house down, etc. Removing the old baseboard fitting might not be too easy, nevermind removing all the water first as well.

Or I could wait for weeks and see if the air scoop removes the air eventually. I've tried a lot of fill/venting with no luck but still can't seem to get the air out. It's not like there is no heat, the gravely sound coming from the pumps as well as the bubbling in the baseboards (more upon initial startup because they get broken up by the moving water, I imagine.) are driving me crazy, and can't be helping the pumps either.

I don't know why they don't put vents in as a rule. When the house water is turned off and a fixture is used or something like that, the air sputters out of an upstairs faucet until it is purged. Seems to make sense.

Ideas?

 

[maple1]

The installers put little bleed valves in my upstairs zones 18 years ago - but I don't use them & don't want to touch them as they had problems with a couple of them leaking then. If I have issues with air in the pipes up there, I can get it out in the basement with the shut offs & drains on each zone down there. My air vents are at high spots in the near boiler & manifold piping down there. Up high in an upstairs zone might be the logical place, but I would be reluctant to cut something in in a place where a leak might go undetected and do damage below.

 

[velvetfoot]

I would be reluctant to cut something in in a place where a leak might go undetected and do damage below.

Me too, but I'm just not getting the air out. This is on the second floor.
I have a vent at the air separator and at the top of the buffer tank. I thought that'd be enough in the basement. The boiler pumps seem to clear themselves out, but not so the zones, esp. the second flor zone.

I'm not super confident, but I'll think I'll give it a whirl. I plan to blow out the line from a drain valve I have at the top of the buffer tank, make a couple of hacksaw cuts on a coupling, put protection around joints, heat up and remove old coupling, install new Tee with 1/8" stub, install Taco Hy-Vent, refill zone - of course that'll be easy because of the new vent (yeah, right).

 

[Bob Rohr]

I'm having a devil of a time getting air out of the zones. There two floors and no bleed valves now in the baseboards. I want to put some automatic air vents on my zone piping. I want to limit to one to a floor because of the hassle. Where is the best place in the circuit to put them?

I'm not even certain how the pipe runs upstairs, but if it's like I suspect, the last baseboard on the circuit is in a walk-in closet that wouldn't exactly be closely monitored for leaks, as well as more of a hassle to install. The place I'm thinking of is in a bathroom, but I
THINK it's the first in the circuit.

I'm trying to think this through as well as not burn the house down, etc. Removing the old baseboard fitting might not be too easy, nevermind removing all the water first as well.

Or I could wait for weeks and see if the air scoop removes the air eventually. I've tried a lot of fill/venting with no luck but still can't seem to get the air out. It's not like there is no heat, the gravely sound coming from the pumps as well as the bubbling in the baseboards (more upon initial startup because they get broken up by the moving water, I imagine.) are driving me crazy, and can't be helping the pumps either.

I don't know why they don't put vents in as a rule. When the house water is turned off and a fixture is used or something like that, the air sputters out of an upstairs faucet until it is purged. Seems to make sense.

Ideas?

Every auto vent you install is a potential leak. Vents installed in living spaces, over finished floors and ceilings are the most prone to leak. With float type auto vents at high points it is good insurance to a a hygroscopic cap for a second shut off mechanism.

At this point, unless you can define all the high points I would not start cutting into baseboards to add vents.

With a quality air separator at the hottest point in the system, IF all the loops are circulating at 2- 4 fps the air should disappear. Bumping the pressure for a day or two may help, keep an eye on pressures if you have an expansion vessel that is sized tightly.

When we installed float type vents in sensitive areas we used a cap with an adapter to 1/4" copper tube and ran it down to the mechanical room or an area safe for any leak or discharge.

Sorry about the pic, my computer must be giving up on me?

 

[jebatty]

Vents installed in living spaces, over finished floors and ceilings are the most prone to leak.

Murphy's Law proves true again.

 

[velvetfoot]

With float type auto vents at high points it is good insurance to a a hygroscopic cap for a second shut off mechanism.

My plan is to screw down the caps if not necessary. I've read that Taco had an adapter for a tube.
I just feel I've tried a lot of filling/venting and thought I'd give this a whirl. The Taco air scoop seemed to get rid of the air in the basement loop. I might add another air separator closer to the pellet boiler at some point-the current one serves both.

 

[maple1]

I have always been able to get the air out of my second floor zones, from the basement. If you can blow the line out from down there as you were planning to do before cutting per post 3, it should be possible to blow the air out with water from down there also.

The caps on my auto vents all went to pieces also - but they are plastic. I could likely replace them with metal if I wanted.

I think if I had to resort to cutting something into my baseboard on the second floor, it wouldn't be an air vent per se, but rather just a stub with a small ball valve on it that I could manually open when I felt there was a need to let air out - and that I could take the handle off of & put a plug in the opening of for the rest of the time.

 

[leon]

I'm having a devil of a time getting air out of the zones. There two floors and no bleed valves now in the baseboards. I want to put some automatic air vents on my zone piping. I want to limit to one to a floor because of the hassle. Where is the best place in the circuit to put them?

I'm not even certain how the pipe runs upstairs, but if it's like I suspect, the last baseboard on the circuit is in a walk-in closet that wouldn't exactly be closely monitored for leaks, as well as more of a hassle to install. The place I'm thinking of is in a bathroom, but I
THINK it's the first in the circuit.

I'm trying to think this through as well as not burn the house down, etc. Removing the old baseboard fitting might not be too easy, nevermind removing all the water first as well.

Or I could wait for weeks and see if the air scoop removes the air eventually. I've tried a lot of fill/venting with no luck but still can't seem to get the air out. It's not like there is no heat, the gravely sound coming from the pumps as well as the bubbling in the baseboards (more upon initial startup because they get broken up by the moving water, I imagine.) are driving me crazy, and can't be helping the pumps either.

I don't know why they don't put vents in as a rule. When the house water is turned off and a fixture is used or something like that, the air sputters out of an upstairs faucet until it is purged. Seems to make sense.

Ideas?

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

Its more like avoiding rather than risking the leaking of the dreaded corner elbow
of a baseboard heating menagerie(I have it and hate it) It will be safer for you to
install a half inch spirovent in the top of your airscoop(s) rather than the $10.00 automatic vents.
The water has to be very hot to vent any entrained air inthe system properly you can
always turn the the boiler temp up and force it to dump the heat in your dump circuit
(assuming you have one).

 

[velvetfoot]

Waiting for second fitting to cool off. Did the second floor first. Cutting removing the old elbows went remarkably smoothly, knock on wood. I got a one-handed recip saw at HD that made the cutting way easy. It has a .5" stroke that made it easy to cut through the elbow that it pretty close to the wall. The air purge went well: it was Boilerman that recommended that, but I've been doing that for winterizing for a number of years.
Will report progress, lol.
Here is the saw. It's pretty nice.

http://www.homedepot.com/p/RIDGID-T...Orbital-Reciprocating-Saw-Kit-R3031/100646504

 

[maple1]

Well now, the truth finally comes out.

New tool = ulterior motive.

(That's nice looking.)

 

[velvetfoot]

Well now, the truth finally comes out.

New tool = ulterior motive.

(That's nice looking.)

Now, that's not me of course. I'd be using TWO hands.

Update: Pumps on. The sound of hissing air is music to my ears.
Will update on further results. (Hey, I'm just going up and down the stairs.)

 

[velvetfoot]

Didn't get rid of all gravelly noise, yet. What seems to happen, so far, is that air is expelled after the pumps rest for a little while. This mirrors what was happening the unending turn on pump/turn off pump/drain cycles, which is not only tedious, but probably not good for the equipment either.

Time to listen for the hiss, and no, it isn't directed at the Giants in KC.

 

[velvetfoot]

No hiss. Maybe it needs a longer rest. The zones are not gurgly now while the pumps are running, but the pumps still sound gravelly, like small air bubbles.
I'm going to turn on the boiler and let it run, and listen for hissing, part time, lol. Did I put the one vent on each floor in the optimum position?: who knows, but hopefully it did some good. It's not leaking, and...I got a new tool.

 

[velvetfoot]

I can't resist. Second floor pump almost quiet. I forgot to do something today and will have to break open the buffer tank to extend the vent/drain valve stub;can isolate is and drain it down a little.

The thing with the vents method, new oxygenated water isn't being injected. If air gets up to the upper two levels in the house, it stands a better chance of making its way to one of the vents on that floor. That's my hope anyway. Hey, I'm just tickled it's not leaking.

 

[leon]

What brand of vent did you use?

What ever you do, do not tighten down the caps as they will not release the trapped air.

 

[chken]

Okay, I'm no expert, I put little air vents at the high points of my zones. Also, it's not clear to me, but if you're getting lots of gurgling, repeatedly, are you sure the auto water fill is working? Mine can get sticky after a year, so I just wiggle it. You'll know if your water pressure in your system is low. If I'm completely off base on what you're talking about, feel free to ignore me!

 

[velvetfoot]

Okay, wife said, why 66 and not 68, as set? Turned out the zones were airbound! I isolated boilers, and flushed at 40-50 psi (well tank) pressure. Incredible amount of air, pretty long time to flush out air. I left the autofill on fast fill and opened a valve part way and just waited; it took a while. Did similar for boilers, headers and tank. Made sure to bleed down to 12 psi autofill pressure before I got them involved. Rediscovered what a siphon was with a hose carelessly left in a 5 gallon bucket; quality time with a mop-need to get a better one. About to start pumps. Fingers crossed.

I'm still thinking the vents might do some good. We'll see.

 

[Bob Rohr]

Okay, wife said, why 66 and not 68, as set? Turned out the zones were airbound! I isolated boilers, and flushed at 40-50 psi (well tank) pressure. Incredible amount of air, pretty long time to flush out air. I left the autofill on fast fill and opened a valve part way and just waited; it took a while. Did similar for boilers, headers and tank. Made sure to bleed down to 12 psi autofill pressure before I got them involved. Rediscovered what a siphon was with a hose carelessly left in a 5 gallon bucket; quality time with a mop-need to get a better one. About to start pumps. Fingers crossed.

I'm still thinking the vents might do some good. We'll see.

Time and patience to do a proper purge. I helped a local plumber start a system today that had 40 radiant loops. It took almost 3 hours to get every loop purged enough so we had flow to allow the air separator to finish off the job.

Volume and pressure is what you need to purge quickly, hence that Autofill with it's 5 gpm flow rate On large pipe systems, like GEO loop fields often times a 1-1/2- 2 hp swimming pool pump is what you need to flush out the loops!

You should be fine now. If the gravely sound in the circ doesn't disappear, we will talk more about cavitation and it's cause and effect.

 

[velvetfoot]

Time and patience to do a proper purge.

Things were quiet til the pumps stirred things up. They were totally quiet at first, then the bubbles from the second floor. I repeated the fast purge on both zones again a couple of times (didn't take as long this time) and got some quiet pumps. The pellet boiler pumps didn't seem to have an effect. Started up the boiler.

I didn't put myself ahead of the curve by blowing out the zones, for sure.

I think the key was the high pressure/flow.

As I said somewhere else, my Air Scoop is on the supply header past the bypass for the Thermomix, so the scoop isn't seeing any flow until 130, and after that, it's mostly going to the tank unless the boiler and zones are on at the same time. I'm thinking maybe another separator, or replace and relocate the current one to the buffer tank supply pipe near the tank. That way the separator will see the flow of the boiler to the tank, as well as flow from the tank to the zones. What do you think?

 

[leon]

Why not high above the boilers where they normally are?

 

[velvetfoot]

This would also be above the boilers. The tankis like 7' high or so and the pipe comes in the top.

 

[velvetfoot]

Bob,
Woke up to the sound of water running in pipe. Heat, yes.

Do you think that spot would be good? The Sirovent and I( think Caleffi work in both directions and requires no minimum length.
I kinda thought the buffer tank with the vent on top would act as an air eliminator.

Maybe I should be more patient.

 

[leon]

One more reason to like steam heat IMO.

The spirotops would be a better choice with an air scoop.

 

[velvetfoot]

Now that I think about it, I should be able to get a quiet system when there is no heat.
I wonder if a vertical air eliminator just upstream from each pump would do the trick?
I get what appears to be a solid fill, and then when the pump comes on, bubbles.
I think I have the first floor solid now with the pump running.
Oh well, back to it.

 

[leon]

If you look at the spirovent/spirotop brochures you will see
how they or other vent types should be plumbed in a heating system.

Pumps are usually flood filled from the boiler base outlet which is
the best way to reduce cavitation to near zero and eliminate any
chance of pump damage and improve pump life span.