Air noise in my hot water system

Rich Lytle

Thanks for the excellent information, Mark. You are right in all aspects: The pumps pump into the boiler, the expansion tank is very near to the boiler, and I have zero faith in the piping job. (Not sure of what my pressure is; will check when I get home this evening.) This guy has re-done all his work about 3 or 4 times, since the each time it was piped, the zones never worked as they were supposed to. He has had to return repeatedly to fix problems.

I've gone back and forth with this contractor for months. I have learned more about hydronic heating than any average homeowner should (most of what I have learned has been through this site), and almost feel at this point that I know more than he does--I have pointed out mistakes to this contractor that he didn't know were wrong. I brought in two other contractors (found them both on this site) and they made lists of multiple problems with the work that was done. (One guy from this site, Steve Minnich, came to my house and spent about 2 hours with me, free of charge, explaining what was wrong, why, and what needs to be changed.)

My biggest problem (besides the fact that the system doesn't work properly) is that I shelled out a lot of cash to have this work done. (Why did I pick this guy to do the work? He told me he does this kind of work all the time, and knew exactly what had to be done. Apparently, he didn't.) For me to bring in someone to fix everything is going to be starting from square one, and as much as I want the system to work, right now I can't afford to do it all over again!

Rich Lytle

Air in my hot water system

Hope you guys can help a homeowner...

I have hot water heat in my 1910 two-story house. Recently I had a new monoflo loop placed in my first floor, and the house was split into two zones: one upstairs and one downstairs. The upstairs is a two-pipe system. The contractor that did the work screwed EVERYTHING up and had to constantly fix mistakes; the project took him about 8 months total. That's a VERY long story.

Anyway, I seem to have a lot of air in my upstairs zone. I can hear the air through the water in the pipes--it almost sounds like a waterfall inside my walls. I have bled the radiators and it does not seem to fix the problem. (I actually try bleeding them every day, and a very small amount of air comes out each time.) The radiators are basically full of water, but the air seems to be in the pipes somewhere.

I'm not sure how to get all the air out of the system. (I called the contractor last week; he came over and looked at it, told me he would send one of his guys over, and I haven't heard back in a week.) Any tricks to getting air out? What other information do you need to help me figure this out?

Rich Lytle

Air in my hot water system

Hope you guys can help a homeowner...

I have hot water heat in my 1910 two-story house. Recently I had a new monoflo loop placed in my first floor, and the house was split into two zones: one upstairs and one downstairs. The upstairs is a two-pipe system. The contractor that did the work screwed EVERYTHING up and had to constantly fix mistakes; the project took him about 8 months total. But that's a VERY long story.

Anyway, I seem to have a lot of air in my upstairs zone. I can hear the air through the water in the pipes--it almost sounds like a waterfall inside my walls. I have bled the radiators and it does not seem to fix the problem. (I actually try bleeding them every day, and a very small amount of air comes out each time.) The radiators are basically full of water, but the air seems to be in the pipes somewhere.

I'm not sure how to get all the air out of the system. (I called the contractor last week; he came over and looked at it, told me he would send one of his guys over, and I haven't heard back in a week.) Any tricks to getting air out? What other information do you need to help me figure this out?

Big Ed

Air Trap

You have a air trap in the piping . A section of piping with a rise and no vent.

ScottMP

Rich

There are a number of reasons, they could have bad piping design right at the boiler.

But check this, go down and look at the preasure in the system. Two stories tall, you should have at least 15 lbs in the system, 18 lbs when the boiler is hot.

If you can take a picture of the boiler we might be able to make other suggestions.

Sorry for your problems

Scott

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Mark Eatherton1

Niagra in the Wall syndrome...

Sounds like you've got more problems than meets the eye. Here are some hints. First off, NEVER attempt to bleed air with the pump running. You're chasing moving bubbles and your tail.

Secondly, one pipe systems are THE worst type of system to purge. You can't usually be succcessful in power purging and must individually bleed the air at each radiator riser. Hopefully the contractor left you a means of doing this.

Generaly, when it sounds like Niagra in the walls, it also indicates improper near boiler piping and improper pressure of operation. If your system pressure is low (~12 to 15 PSI) and the pump is pumping toward the boiler, AND the expansion tank is connected at the boiler, it's a recipe for Niagra in The Walls syndrome.

FIrst off, see if you can find a competent contractor at the Find A Professional button here at the Wall. No guarantees, but if they hang here at the Wall theres an EXCELLENT chance they understand the principles of "Pumping Away". I can't tell you how many systmes I've made virtually silent by doing a proper job of near boiler piping.

Under worse case scenario, go to Dans books store, located at Books and More, and buy two books. "How Come", and Pumping Away". Give (lend) the contractor these books and tell him what you want done. If he balks, find someone who will. You won't be sorry. Report back to us after the fact if you will please.

Good Luck and sorry youu got caught between a rock and a hard, wet spot.

ME

Dale

1910

Another thing to consider, if the system is as old as the house was it originally a gravity system? Splitting a gravity into zones and adding a pump can really affect flow, especially a monoflow zone. If the original pipes in the basement are really big, like 2 inches read up to the left on gravity conversions.

Rich Lytle

Thanks Scott

I'll check the pressure tonight and post a few pics. You aren't going to believe what a tangled mess the pipes are. If it is possible for near-boiler piping to cause this problem, then that's probably it!

Rich Lytle

I imagine it was gravity fed

It most likely was a gravity-feed system. When I moved in a year ago, the boiler that was in there was the ORIGINAL boiler from 1910. It was a monster! I had it replaced about a year and a half ago.

Mark Eatherton1

Make the contractor fix it...

and if he balks, contact your DA for fraud charges. It's perfectly within your rights. If the man wants to come here and learn what we know, we'd be more than glad to help him out. But for him to charge you somethiing, and not be able to deliver, and TELL you he's good at it is fraud. Plain and simple.

If I screw up a job (and have..) I fix it at MY expense, not the CUSTOMERS expense. No one's perfect. It's how they handle the tough situations that counts. And if and when I do screw up, I let the custome know so that they perceive the value in my services AND honesty. It goes a long ways toward good will. Now all we have to do is find some PEACE on Earth...


One of these days these hot water jockeys are going to get a hint. Until then, good luck. Steven Minnich is a good man. I own one of his daughters hats.

Happy Hydronicing Holidays!

The Gimp (ME)

Rich Lytle

OK--lots of pictures of my system, and a LONG story!

I took some pictures of my system; I hope this gives you enough detail to see what is going on--I know it can be tough without physically being here.

As I wrote previously, this system has been piped and repiped MULTIPLE times by the contractor over the course of the summer, since every time they finally got everything together (which always took weeks in itself), it never seemed to heat the right radiators in the right zones at the right time.

First some background: When I moved into this house 2 years ago, the boiler was the original from 1910. I immediately had that replaced with a new boiler. Then the weather turned cold. That's when I realized that the ONE RADIATOR I had on my first floor was not heating that floor adequately, while the FIVE on the second floor were cooking me. That's right--I had one radiator on my first floor. Each bedroom upstairs has one, the bathroom has one, master bedroom has two, for a total of five on the second floor. So you can see my problem. (BTW, I am a first-time homeowner and didn't know any better--at the time--and of course the previous owner didn't say anything about the problem.) My guess is that at some time radiators were removed from the first floor for remodeling or whatever, and nothing was ever put in its place.

I toughed it out for the rest of the winter, and the next spring I started calling around to contractors. Every single one I talked to gave me different recommendations of what I needed done. I didn't want baseboard heat, since the rest of the house has cast iron free-standing radiators; I wanted to stick with this theme. I was continuously told that they don't make radiators like that anymore. One contractor did say he could get them, but they would be about $2000 a piece! I decided to take matters into my own hands. I went to a salvage yard in downtown Chicago and found two identical 7-section cast iron radiators that matched my current ones for 280 bucks out-the-door. I brought them home and cleaned them up. I also bought a Myson toe-space heater that I wanted installed under my kitchen sink cabinet.

Then I found this contractor that said he had been piping boiler systems for 20 years (or something like that) and told me he could split the house into two zones with separate thermostats so I could control each floor separately. Sounded good to me. Little did I know he had zero quality control, didn't pay attention to what his installers where doing to my house, and didn't know the right techniques for integrating an existing system with a brand new one. It was a long summer... I could go on, but I won't.

So here's the layout: Basically, there are two zones: the first floor, which is a new monoflo tee loop with three cast iron radiator branches and one branch to the Myson, and the second floor, which is a two-pipe system with five radiatores: three radiators are on the west side of the house off of two pipes, and two radiators are on the east side of the house off another set of pipes.

These pics try to capture most of the system. I'll walk you through it.

Here is a pic of the boiler. The pump on the left runs the first floor loop, the pump on the right runs the second floor.


Another pic:


A pic showing the tangled mess of pipes:


Here we go.
Water starts from the boiler and goes through this expansion tank:


Then it runs up and hits the split for the two zones. There are zone valves that open according to which zone is calling for heat. (These were an afterthought.) The top pipe runs to the monoflo loop on the first floor, and the bottom pipe feed the second floor.


Another shot:


Next, the bottom pipe splits at this tee to go the the west side second floor, or continues straight to go to the east side second floor.


This is where the new pipe meets the old pipe to go to the second floor west side: far pipe is supply, near pipe is return.


These two pipes head to a small radiator in the bathroom.


And these two run to two radiators on the second floor. THESE PIPES ARE WHERE ALL THE AIR NOISE IS COMING FROM! I can hear water running through them like a waterfall.


They run up to here, and then split to go to a radiator in each bedroom. This pic is taken in the bathroom access panel in the master bedroom. You can see the two pipes splitting in both directions.


The pipes running towards the bottom of the previous picture run to this radiator. THIS RADIATOR is the noisiest, but when I bleed it, I get nothing but water, which means there is NO air in the radiator.


Here is a pic of the pressure and temperature gauge:


So WHERE do you think all that cascading waterfall noise is coming from, and how can I get rid of it?? I hope all this makes sense... sorry for the long post! Thanks in advance for your help!

Mark Eatherton1

OKay...

I've seen the evidence and am ready to pass judgement:-)

Oh yeah, I forgot, I'm not allowed to judge, so instead, we will critique!

You have all the parts you need to make heat move. That's the good news...

The bad news is, some of them are un-needed and others are in the wrong spot. But it's workable. I have some more questions for you. It appears that what you have is a two pipe parallel direct return system on the second floor. If you could get me some pictures of the branch tees for the system serving the main floor it would sure help.

What interests me is the fact that you installed a piping system that hasn't been installed recently by any one I know except myself in my own house. You did say it was a one pipe monoflow tee system, correct?

Back to the upstairs, what I think you're hearing is what I have referred to in the past as "impellance". Don't try looking that up in your Funk and Wagnells. I invented here, on The Wall...

Impellance is the mechanical force imparted to the water by the impeller. Gettin' a picture in your head yet?

You've probably seen impellance before and didn't know what it was. Ever seen one of them reflecting ponds with a recirculation feature, and out of no where, this upside down tornado pops up in the reflecting pool and swings around wildly. That's impellance!

The key to avoiding impellance noise is to cause the impellance to be positive, instead of negative. If the pump generates positive impellance at the system, there won't be any vortices', and there won't be any noise issues.

There probably WILL be an imbalance in flow, but that's the nature of the beast. That can be overcome by "balancing" the flow with the radiator valves that are on the radiators. They appear to be the old 1/4 turn valves. They go from 100 percent open to 100 % closed in a quarter of a turn. Or was that a 1/2 turn... Oh well in any case, you'll want to partially close those radiators closest to the pump, and keep the rad's the farthest away from the pump mostly open.

If you balance it now, you will just spread the impellance noise out over numerous radiators, and the system might quiet down, but it won't work perfectly until you set the pumps up so that they can "pump away" from the expansion tanks connection to the system. That can't be done without draining the whole system. You could replace the zone valves with check valves, and don't forget to leave a means of draining the system down stream of the check valves. The zone valves are not necessary if check valves are used. Just one less thing to go haywire in the future...

Show us your one pipe fittings and make a simple drawing in paint if you could.

Happy Holidays

ME

Rich Lytle

Here's a diagram of the system

Impellance makes sense, in the fact that it is a "tornado"-like vortex of water running down the pipe. This would mean that it is only on the return pipes, correct? It would also mean that air is trapped in the pipe somewhere then also? (Something has to make the noise.)

Yes, the first floor zone is a monoflo loop--that is what I had installed. It is totally silent and minimal (if any) air comes out of the radiators when bled. The second floor is a two-pipe system, and that is where the noise is occurring. Specifically, it is all on the west side of the house.

Take a look at the diagram I made. This is a fairly accurate and to-scale diagram. The monoflo loop on the first floor is in yellow. The red pipes are second floor supply, and the blue are second floor return. The arrows mark the flow of water.

The pipes on the LEFT side that run to the radiators on second floor is where the "Niagra falls" sound is coming from.


You are right about closing the valves--that does quiet down the gurgling a bit. (These valves don't completely shut off the radiator. Since they are 93 years old, they are probably a bit worn out.)

But I wonder if there is any way to get the air that is causing the noise out of these pipes...? I would think it would migrate to the radiators, but when I bleed them, I get mostly water, so there must not be any air in there.

Is this problem truly a function of the way it is piped? Would changing the pipe configuration at the boiler correct this problem?

Mark Eatherton1

Absolutely!

Guaranteed!! Or DOUBLE your money back...

Like Heatboy sez, It's not "you get what you paid for," it's "You didn't get what you DIDN'T pay for", or as some people who don't get it say "No charge for the noise..."

There is no air in your system, other than the h2O that comes out of suspension in a vacuum, which is what you're hearing. "SOUNDS like air, doesn't neccesairly mean it is air. Cavatation CAN sound like fire crackers going of on the inside of the pipe. But were pretty sure there are no firecrackers in there...

Try it once, and you'll never go back. I'll even dig up a drawing here to help you along you way:-)

Merry Christmas.

ME

Mark Eatherton1

Near boiler piping dwg...

Here ya go.

ME

Rich Lytle

Thanks Mark

I'll show that drawing to my contractor. (I already told him about the benefits of "pumping away," but he didn't buy into it.)

I doubt he will be willing to change it. That would mean he would be starting over AGAIN!

I wish I had known about all these things before I had this work done. There has been a continuous stream of errors made in the installation of this system. It would have been nice have everything done right from the beginning... but I guess I was relying on my contractor to know what was right.

Mark Wolff

Layout

Hey Mark, what do you think about putting isolation valves on the return of each pipe and adding a boiler drain before them to allow for quick air purging and line filling?

It looks like you fill your zones with reverse flow, but wouldn't that defeat the directional flow air removal from your air seperator?

I normally fill into the boiler, run the water zone by zone into the loops, with the return iso valve off and the boiler drain open w/ hose attached. It seems to really get all the air out of the loops. Just a thought.

Let me know what you think; maybe I am missing something that you corrected with that design. Thanks.

ScottMP

Zones ?

Rich ,

You said you had two zones, but you have two circulators and two zone valves so thats three zones, right ?

Is the second floor two zones ?

I don't see any flow checks ? Is he using the zone valves as flow checks ? Does each pump have a zone valve ?

If you truely have Two zones ( first and second floor ) then Get Rid of those zone valves. I have no idea what they are doing there.

The sound is only from the second floor ? And only from one side ?

Scott



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Mark Eatherton1

Filling column radiators...

generally is done from the bottom up through the bleed valves at each radiator. You can't force purge these systems. You set the fill valve at 12 to15 PSI, let the presure stabalize and start bleeding air from the radiators closest to the boiler, then work your way outward and upward. Any minor air trapped in fitting etc will either work their way to a bottom tapped radiator and float harmlessly up out of flows way, OR work its way back down to the air seperator.

Once you're done purging air, fire the system for an hour, shut it off again and go back throught the radiators for the final burping. Labor intensive for sure, but if done properly, you are DONE done.

Also, these systems would have to be completely drained to do any work on the radiators because the stops on the rads' are only on one side, and they're not positive shutoff stops.

Hope that answer your questions.

ME

Rich Lytle

Yes, two zones

Each zone has its own pump, and each zone has its own zone valve. One zone is the first floor, one zone is the second. When one zone calls for heat, that zone's valve opens and the respective pump starts pumping.

The reason the zone valves were installed was because somehow, when the first floor zone (only) was on, hot water migrated to the second floor radiators on the west side of the house. It actually ran in the opposite direction, through the return pipes for those radiators. So the contractor installed those zone valves to completely shut off each zone when it wasn't running.

I can't remember exactly how that was happening, since I think he might have changed the configuration around (again) when he installed the zone valves, but logically following the piping, it was possible--and it did.

Yep, the sound is only from the second floor, and only the two larger radiators on the west side (the left side in that diagram).

Glenn Harrison_2

Hey Mark, how about using Steamheads pump sizing chart

to resize the pump for the second floor? He did say the pipes are very large, like the system was originally gravity. Maybe if he could get his contractor to put in a smaller pump to simulate gravity flow like Steamhead suggests, he could get the noise level to reasonability, and convert to pumping away later, when he's ready.

Just a thought.

Mark Eatherton1

Good thought...

he's only running 007's now tho... What do you think Steamheads calcs would call out. A 005 or a 003.5?

Lemme know whadya think.

ME

Glenn Harrison_2

Problem is,

I havn't had a chance to use it yet. That's kind of why I threw it out to you, I thought maybe you had applied it to a job.

I am thinking though that maybe changing both those pumps to Grundfos UP15-58FC pumps, and setting the upstairs zone on low speed might do the trick, and it would also get him a set of flow checks in there to help get rid of his ghost flow, that the zone valves currently are trying to correct. Just my thoughts tho, and anyone can feel free to dispute them.

To Rich, if you wondering what chart I'm refering to, check out this link, it's located in the "Hot Tech Topics" section here at HeatingHelp.com.

http://www.heatinghelp.com/newsletter.cfm?Id=125

Steve Miller

No Pri/Sec?

ME,
The drawing looks great but wondered why you didn't include pri/sec pumping and boiler protection? Radiators and big steam pipe can suck out the BTU's and produce low return temps and cause problems.

Call me curious, Steve

Rich Lytle

I think fixed the problem... for the time being??

Well I think I figured out how to quiet the noise. I lifted the lever on this:

which I figured is the fill valve for the system. I could hear the water running in when I lifted the lever. I filled it until the pressure was just around 20 psi. When the second floor zone comes on and the water is hot, it climbs to around 23-24 psi. And seemingly, I can no longer hear the water rushing through the pipes.

How does the fill valve work? Is it supposed to automatically add water to the system when the pressure falls to a certain level? What level is that? Or does it only add water to they system when the lever is lifted?

However, the pressure in the system seems to drop off on its own. A day or so later it was down under 20 psi. My only guess is that the water comes out here:

which is the pressure relief valve I think. I never saw any water coming out of here though.

How does this pressure relief valve work? Is it possible water comes out of there that I am not noticing? Does it make sense that the higher pressure quieted my system? Is this a long-term solution? Is it safe for my system?

TIA!

Mark Eatherton1

Yeah...

raising the pressure will quieten the noise, until the presure drops again. By increasing the pressure, you've increased the flash point of the oxygen in the water, hence it's quieter. It's still not right, but will continue to work with air noise and air issues.

It's ak for your system too.

ME