Hydronic System - "Whoosh" Noise

Redrum

Hi;
First, a description of my system:
Buderus GA124 Boiler, Taco circulator pump,
4 taco zone valves on the return side:
a) 3 zones, upstairs, basement, main floor are 1" piping, but neck down to 3/4" at the baseboards, as I replaced the baseboards
b) 1 zone is a panel radiator in a sun room, just added, 1/2" piping. Note the noise occurred before I added this zone
Air Separator and expansion tank on the return side, between the zone valves and the boiler
Outdoor reset.

Now the problem. I get an occasional "Whooosh" sound that you can hear throughout the house, and when it't cold (I am in western New York), it happens alot more frequently. I would say the duration is 1-2 seconds.

If I turn the zone valves on and off by themselves, it does not occur. But, it seems to occur when a valve closes while another remains open. In other words, it seems like it happens when a zone valve closes while the pump is still running.

I don't think I have air issues, as the system is very quiet when running, outside of the noise of the expanding and contracting in the radiators?

Of note, the system (boiler, reset, zone valves, etc) is about 2 years old, it replaced an old Weil McClain system. I mention that because I never heard the sound with the old system, so I don't suspect any field piping issues.

Any thoughts?
Jim

Rich_49

What circulator is this which is installed in the system ?

Dave H_2

Red,

So what Rich and I want to know is which model of Taco circulator is there and also the model of zone valves.

Dave H

Redrum

Hi, thanks for participating in my quandary

My mistake, the pump is is a read hard to access location, so I thought it was taco, but it is not. It is a Grundfoss UP Series. Not sure which size, as I would have to use a mirror to read it as the face is about 2" from the basement wall (I could if needed). I have attached a picture.

The ZV's are Taco Zone Sentry Zxxxc2-1, where for xxx, the four are 100's or 075's for 1" and 3/4" respectively.
Jim

Rich_49

First off , try moving the lever to low setting and see if that helps .

Redrum

I did and I didn't think it helped, but will try it again tonight when it gets colder. Why would a pump have different speed settings? Wouldn't that affect the temperature out vs return (change the velocity of the water, but the thermal distribution is the same, and therefore affect the heat exchange? I never quite understood why this pump has different settings.

Dave H_2

Red,

The circulator is probably a UP 15-58, 3 speed circ. Different speeds to try to match different applications, loads, etc.

You probably don't hear the noise when all 4 zone valves are open and only one zone closes, but more often the noise appears when 3 or less zones are open. Please verify.

I am also going to assume that your 4 zones are not very large heating zones

But I have heard this complaint often enough and lots of times it happens with 3 speed circs and zone valves.

3 speed circs can create high head at low flow requirements and low head at high flow.
If your zones are not very large, the change in flow/head are drastic along the pump curve to create that noise.

A fix is to change to a circ that doesn't have high head at low flow requirements like the Taco 007

Dave H.

Redrum

Thanks Dave, makes sense, will do some testing of the various scenarios and get back to you. If I disappear for a couple days, it's because I am testing, not blowing you guys off, ok? will report back.

If it mean anything the old circulator pump (that didn't make noise) was the old B&G style, open cage, that you had to change couplings and bushings every so often, I am sure you know what I am speaking of....
Jim

Redrum

Hi
Ok, first the background:
1) My pump is a UPS 15 - 58FC
2) I forgot to mention (oops) I have a fifth zone, the indirect water heater
3) Zones 1 and 2, upstairs and downstairs, basically route along the perimeter of a 26' X 30' footprint of a cape, with the upstairs being slightly smaller due to dormers, but, more vertical, so I would say these loops are about 110'.
4) Zone 3 is basement, just one wall, so, say 60'. This zone is usually not even used (turned off)
5) Zone 4 travels about 50' round trip to a panel radiator in a "sunroom/mudroom"

Now the test, first pump at mid speed:
1) All zones on, water temp between high limit and diff, turn one zone off, noise - slight.
2) Remove a zone at a time, turn same zone off, noise - louder
3) Down to 2 zones (1 and 2) turn one off, noise about the same, maybe louder.
3) Repeat with zone 4 (1/2" CU) and 2 (1" and 3/4" CU) on, turn 2 off, noise, maybe loudest, hard to tell.

Finally, turn the pump to low, repeat above, noise is still there, maybe quieter? hard to tell.

Maybe this pump is incorrect even with the three settings?

I didn't mention before, but in my old system I had a purge and balance valve per zone that I never used as a balance, i.e. it was always open full, except to purge. This was replaced with a single similar valve, used only for purging. Do I possible need some balance?

Also, when the installer came back to install the reset, and try to address this noise, he fiddled with alot of setting in the beckett aquastat, like he has the pump on delay real long. perhaps should I go back to default?

Thanks for you help, I think you have narrowed down very quickly something that had me baffled. I had when solved, I just didn't know why.

Jim

Paul48

The B&G circ you were describing was probably a series 100. It's a flat curve pump, similar to the 007 that Dave recommended.

kcopp

Sounds like Hydraulic jump.
happens when you have a large pressure jump in the system when 1 zone valve closes on a multi zone call for heat.
One solution would be to install a Delta P circulator.
Examples would be a Taco Viridian or a Grundfos 15-55.

Alan (California Radiant) Forbes

So, you have lived with this sound for 2 years?

Curious that the noise only lasts for 1 or 2 minutes and then goes away. And that lowering the speed with the selector switch doesn't make much difference.

My knee-jerk reaction was to call over-pumping when only one or two zones were calling; going with a smaller pump or adding a pressure differential bypass to take care of the problem.

Can you post some more pictures of the zone valve piping and the piping around the boiler?

Thanks!

Paul48

I have a feeling the noise is created at the closing zone valve. He said the duration was a second or two.

Gordy

Quite possible air may compound the sound, and or changed piping anchorage in the system transferring the noise.

Redrum

First, thanks to all that are pitching in with your thoughts. You guys are great.

Alan - my mistake, the new system has only been installed for a year, last February, then spring, summer came, "I'll address it in the fall", followed by an unusually warm fall through December, I was reminded of it in January.

Also, the sound is maybe one second. Count "one thousand one" and the sound is almost complete. It's a "whooosh" where the sound grows and decays (slightly). There are mild ones and loud ones, and of course is more frequent the colder it is outside before the sun.

I'll attach some more pics. let me know if you want an others. The supply from the boiler goes through the circ, to a 1 1/4" manifold, T's out to the zones (1"- 3/4", 1/2") then returns to the ZV's, T's to another 1 1/4" manifiold, through a purge and balance, to the air seperator/expansion tank, back to the boiler

The photo "supply" showns the circ up to the manifold, and, forgeround to background, the zones downstairs, upstairs, basement, porch (panel radiator 1/2"), Water Heater (horizontal run)

The photo "return" shows the ZV's in the same order, but photo is taken from other side. Seperator, tank, to boiler. The "spaghetti" look of the piping is due to retrofitting to the old system, which was the previous homeowner's self install. His goofy install, combined with growing up with hot water heat, helped me learn alot and provided me years of challenges until I got the new system.

Paul, yes, the closing of a valve when another is open, i.e. circulator is running causes the sound. I can replicate it.

Gordy - I won't rule out air, but the air aspect of the system is whisper quiet, and I have even bled at each radiator. Plus, it does not seem to be associated with any particular zone. Also, regarding anchorage, I do hear the usual expansion "pings", in fact, interestingly enough, I often hear a "ping" immediately before each "whoosh". I do know some ouf the routing through floor openings and such are tight.

happy Sunday, all!
Jim

Harvey Ramer

I have a couple of questions..

Do you have a control for the zone valves or are they wired off of a transformer?

How are you prioritizing DHW zone?

Do you have a separate signal to the boiler to override the ODR control upon a call for DHW?

Is the pump controlled off of the beckett aquastat? If it is and your zone valves are wired off of a transformer, the zone valve will close before the boiler receives and open contact to turn off and the beckett aquastat will likely keep the pump running to post purge. But the zone valves will already be closed and you'll be dead heading the pump. Another thing, if the zone valves are wired off of a typical 40 VA transformer, it won't have the required power to open more than 2 valves simultaneously. If more than 2 zones are trying to open at the same time, it may cause the valves to open slowly causing the wooshing noise.

I think you may to install a Taco ZVC405 zone control and let it control both the circ and the valves. That will give you all the flexibility you need to properly control your system. It will also clean up that wiring mess.

Harvey

Redrum

Hi Harvey;
Bear with me, I understand the basic of the controls (themostat, ZV, pump, etc) but once I get beyond that, I just don't have the experience. However, I do have a good understanding of electrical/electronics, so here goes:
1) There is a separate 24vac transformer that the ZV's and low water cutoff run off of, and they feed back to the aquastat inside the boiler.
2) I am not sure that the DHW is prioritized (but as I said I could be wrong). I have not wrung out the wiring (nor did I get a schematic), but it appears:
a) all ZV's are run in parallel, including the end switch, so it seems any ZV on = one switch closure in the aquastat TW/TR.
b) There is a wire from the DHW tank that appears to terminate in a thermocouple or similar, so I imagine that is the tank water temp "thermostat" to call to heat. This runs to the ZV for the DHW.
c) An option in the aquastat control is set to "DHW on Zr", but nothing is connected to Zr. It appears that the parallel chain of the ZV's are hooked to the thermostat TW/TR.
3) Pump is controlled from the aquastat

Regarding your dead head comment. The noise occurs when 2+ zones are open, and one closes so the pump will still be running, but, based on your comment I ran an experiment, and when only one zone is running, and it no longer calls for heat, both the pump and ZV shut down almost immediately.

Regarding the transformer, good thought! I would have never considered that. I checked and it is AT140A1000. 40VA, 120VAC to 24VAC. The ZV's say they use 0.48A "charging" (changing?), so that would be 12VA. Perhaps it is too small for 5 ZV's. Good thought, but I only get "woosh" when one is closing while the pump is running.

Thanks for the recommendation of the Taco ZVC405. I'll check it out. I like system mods that don't require draining the boiler in winter .

Sincerely, thank you for your input. I know we will kill the woosh and learn so much in the process!
Jim

Redrum

general question, does this forum have an option for an e-mail alert if you get a bump on a discussion that you are involved in?

Redrum

Perfect, thanks HG.

Alan (California Radiant) Forbes

As an experiment, you can partially close the ball valve after the pump, say halfway in order to throttle down the force of the circulator. Do it with the circulator on the lowest speed and see if you still get the sound. If the sound goes away, you have at least two options:
1) change the pump to a smaller pump
2) add a pressure differential bypass

Changing the pump to a compensating circulator like the Grundfos Alpha might not work since I don't think it would compensate quickly enough to void the whooshing.

Redrum

Thanks Alan, I'll try that tomorrow and post my findings, appreciate your insight.
Jim

Redrum

OK, here are today's findings:
1) I tried Alan's suggestion and closed the ball valve after the pump 45 degrees (1/2 of the 90 degree travel), with the pump on "Lo" - It did not kill the sound, and I am not sure I can say it reduced it.
2) A new observation - the sound starts, and ends, with the travel time of the closing ZV. That is, at least 2ZV's running, one turns off at thermostat, then ZV starts to rotate (sound starts), and finished rotating (whoosh complete).
3) New observation - there is a much quieter opening sound that I am only able to hear with the basement zone (because of the proximity to the boiler). This could be just the motor noise of the ZV being transferred through the pipes.

Finally, I have attached a *.wav of the sound. You can hear that the mic picked up the zv motor noise and that they coordinate. before you say "that wimpy sound?!" it's the best I could do with a phone, and the sound can and does radiate through the house (sometimes subtle, sometimes not so).

Since the site does not allow wav to be uploaded, I put it in a zip, no password required

Jim

Harvey Ramer

What model pump do you have? Maybe you can stick your phone behind it and snap a picture if you can't see.

Some good pipe clamps solidly mounted will probably help. You need to remove those metal straps that are currently holding up the pipes, anyway. If you don't, you'll get a corrosion mess and more likely than not, leaking pipes.

Looking at the pictures again, I'm saying your primary source of the noise is due to microbubbles suspended in the fluid. Your air seperator should be on the supply side. The Taco air scoop that you have installed, requires 18" of straight pipe going to the inlet, for it to work properly.

Hilly

Is it me, or was it silly that the whole system was re-piped in the fashion that it was? Would any of that played a part?
- zv's on return
- Line Scoop without proper straight length clearances
- line scoop on cooler return, although I imagine with the indirect the return temps get pretty high at times & the higher return temp requirements for the CI Boiler probably through this point out the window
- is the float vent in the line scoop open
- is the float vent faulty from the recent panel radiator addition
- also would the hydraulic jump be more prominent with the zv's so far away from the pump on the return side?

And I believe the number of Sentry's on the 40VA should be fine according to speak. I thought that was one of their selling features - in that they were big energy conserves and would save you the typical VA requirements.

Redrum

Hi Harvey - I used a mirror to get the pump number earlier in the thread, it's UPS 15 - 58FC

Let me digest the other comments, I certainly appreciate all of them.

Were you guys able to get at the wav file of my whoosh?. Kind of funny just saying that

Harvey Ramer

Got your whoosh.

Unplug the power cable to the burner and the turn the system on. Make sure your domestic doesn't zone doesn't call. Allow the water temperature in the system to drop to around 70-80 degrees and then see if you get the woosh. Or if it is as pronounced. The colder water will absorb microbubbles. That should help with the diagnosis.

Mark Eatherton

Another simple test. Turn the burner to pilot (if gas) or off (if oil). Then completely close one of the isolation valves for the pump, and cycle thermostats. If the noise is gone, then its a velocity issue. If the noise remains, it is the CD motors on the zone valves you are hearing.

If it is a velocity issue, it can be alleviated by going to a smaller, properly sized pump, or installing a pressure activated bypass across the pump.

If it's not a velocity issue, it is the nature of the valves. They do make somewhat of a grinding noise as they open and close. That pump does have a fairly steep performance curve.

To properly size a pump, we'd need to know the longest developed length, pipe size, number of elbows, valves etc and linear feet of convector connected to that loop. We also need to know the total linear footage of baseboard connected to the boiler.

ME

Redrum

Hi Harvey, mark,
Thanks for your input, I'll run both sets of tests tomorrow and post back.

Mark, understand the thought on zv noise, even transferred along pipes, but, I do hear that noise on valve opening, but it's only the loud whoosh on close, and only with pump running. No whoosh if it's only one zone open and close.

I did post approximate loop lengths earlier, but would be happy to gather more accurate loop lengths, radiator lengths, elbows, and number of elbows and 3/4 - 1" transitions ( field is 1" and as I remodeled each room I replaced the baseboards, and the only available were 3/4" (Weil mc I think). Probably best to diagram

More tomorrow, thanks again to all
Jim

Redrum

Some of the info, some questions -
Hi Harvey - I was unsure of where to unplug the power cable to the burner, and I have the guts to mess with just about everything...except gas. I get nervous. Please see the attached picture, not sure if I was supposed to disconnect the Main/Pilot Valve Cable (3 conductor)?

Anyhow, it was 65F here today so the boiler was hanging out with the water at about 95 degrees. I opened two zones via the stats, the burner fired up, zones opened, pump ran, and because of field water, the temp stayed below 90 - 95 (according to the aquastat). I closed one zone and "whoosh". I can't say it's any less prominent than in the past, but by nature, the sound intensity can vary.

Hi Mark - I didn't get off the ground with your test because I couldn't find a pilot (see attached photo), I imagine that to go into a pilot only, and no burner state is controlled somewhere else? Maybe the aquastat? Again, I have no guts when it comes to gas.

Also, if I am closing one of the isolation valves for the pump and running it, am I not dead heading the pump? Is that ok for a short trial? If so, can't I do that with the burner on?

I know what your test is trying to do, if no water is moving that the stats are controlling the zv, and if I don't hear the sound, it's not the stats. If I do, it's not the water V.

I'll start to put the data together on my system. In the mean time, feel free to tell me "no, no, no, unplug that cable!" and I'll be happy to complete the tests.

Appreciate the help, can't say it enough.
Jim

Mark Eatherton

Turn it to the OFF position, and do the test. You don't have a standing pilot. Reason for shutting off burner is for quietness and not a good idea to fire a boiler with no circulation.

Dead heading of small circulators is perfectly fine for short periods of time. I have seen small (Taco 007) dead headed pumps that had been that way for YEARS, and nothing blew up... As soon as I opened its isolation valves, it started moving water.

ME

Redrum

Will do Mike -
One thing I noticed while mapping out the runs - the taco sentry zv's are all Z100 (1") except for the hot water and panel radiator zones which are z075 (3/4") as identified on the motor head body. But, I noticed that while the sweat bases are all correct (obviously) to the exit pipe size, two of the motor heads is installed improperly (swapped). That is, there is a 100 on the base that has 3/4", and a 075 on one of the bases that has 1" exit. Looks like it was like this from the original install (i.e. plumb then install bases after). Should that matter? I am thinking perhaps that if anything, the motor or coils in the 100 would be beefier to drive the bigger (assume) valve actuator?

I'll go back to Mike's test and mapping the zones, but wondering if anyone has any thoughts on this. I could call taco as well.

Jim

Redrum

Hi Mike, Harvey;
It seems to be velocity related based on your tests. I turned the burner to off, closed the isolation valve near the pump, noted that the water temp was about 85 degrees because of the nice day here, opened two zones through the stats, zones opened, and system thought it was heating the water (exhaust fan on, but water temp remained constant).

The pump is so quiet I have to rely on the aquastat to tell me if it is running, and it doesn't if it is trying to heat water. I "almost" miss the old B&G pumps where you either heard them or just looked into the opening to see the coupling turning. I said almost.

Closed one zone, no whoosh. I did hear the zv noise being radiated a bit by pipes with no water running through them, but it's very minor compared to the whoosh.

Opened the second zone again, opened the isolation valve, water temperature still cool, closed the second valve through the stat - whoosh. Not to say that I don't have microbubbles of air (and if I do, being anal, I'll want to get rid of them!), but the whoosh doesn't seem to be heavily related to the temperature of the water. having said that, when I am not standing next to the bolier testing, sometimes I hear the whoosh soft, and sometimes quite loud (especially in the morning), and have wondered if water temp, colder outside temps before the sun is up, which zones, etc. etc. play a part.

Finally, remembered to turn the gas back on, it's still winter until may/june, right?
Jim

Redrum

Hi, I have mapped out my system. Even if it doesn't help with the whoosh, it's never a bad thing to have for reference. I have attached the 4 zone (plus HW is 5th) in schematic form if needed. Please don't feel obligated to go over it, if you do, you should be getting paid, right?

It does indicate the 90's and 45's.

In summary:
Zone 1 - Downstairs - mostly 1" pipe, but 3/4" at most of the radiators. Loop is 148 feet, of which 43' are radiating elements.
Zone 2 - Upstairs - mostly 1" pipe, but 3/4" at the radiators and in some cases, approaching and between dormers, I ran 3/4" as I had access to replace pipe when I had the upstairs gutted (wasn't buried in the floor). Anyhow, loop is 170' (including verticals) of which 36 feet are radiating elements.
Zone 3 - Basement, rarely used, 1" the whole way, basically a "there and back" run. Loop is 60 feet, 16' of it is radiators.
Zone 4 - "porch/sun room" - this is new but note that whoosh was there before this zone. It's a 1/2" run, loop is 52' (note, document is wrong, it has 104'), terminates at a 24 X 24" panel radiator. There is a flow adjust on the panel that is wide open (because it's on it's own zone I reasoned). There also is a diverter valve that I installed mostly because it made a clean 90 degree interface to the radiator.
Jim

Mark Eatherton

Let me run some calcs and get back to you tomorrow. You came here seeking help, and I appreciate your offer to pay, but the fact that many others are learning from your experience is all the payment we need here.

If you'd like to donate to this web site however, feel free to purchase a Brick or two for The Wall. $10.00 each.

http://store.heatinghelp.com/support-heating-help-s/1830.htm

ME

Mark Eatherton

Got bored with TV and came down and fired up a couple of PC's to get your answer.

At present, the Grundfos pump is pushing the following, assuming all zones calling. Starting with basement and going up, 7GPM, 4.5 GPM and 4 GPM. This assumes speed 3. BTUH transferred = ~33,600

For speed one the numbers are 3.85, 2.42 and 2.16. with BTUH transfer = 36,200 Not a big difference in transfer for difference in GPM.

BTW, on speed one, the pump is moving high GPM and producing low head which is hard on the motor (over load). Warning popped up on software.

The 1558 is the smallest pump in this software (Siggywerks).

If you drop back to a Taco 003, it too pops up with an overload alarm, but FYI, its moving 2.55, 1.6 and 1.4 GPM respectively. MUCH slower velocity, but then air hang up issues could raise their ugly heads.

If I shut down the shortest zone, GPM's don't increase significantly, and at no time do any of the flows exceed recommended velocities. I think what you are hearing is the nature of the beast. That beast is water. As you pinch of the flow of a stream, it generates noise. With the system running full bore, you can make this same noise at the circulator isolation valve by closing it quickly. More of a HISSSsss than a Whooshhh, but you can hear it for sure. It is a field method of checking for flow on extremely quiet pumps like this. HISSSsss = flow. No hiss = no flow, or extremely low velocity flow.

One choice would be to choke flow on each return to slow the water, but those air problems could arise due to the use of 1" pipe. The only other option would be to replace the valves, but in my minds eye, that's one of those comfort noises. It instills comfort in your mind knowing they are working as they should be... But it is your home. All valves make some noise when they close. You'd just be trading one type for another.

BTW, this whole system could have been done in 3/4" and would have worked great. Must have gotten his hands on some cheap 1" tubing...

What may have changed is that the upper loops were partially air bound before due to poor purge, and when you repurged them well, the system started flowing as it could, extremely well.

Without eyes and hands on the system, it's hard to say, but you know your options now. Enjoy!

ME

Redrum

Hi Mark and all;
Thank you, thank you X 100 for your thoughts, time and effort. But, I don't see options to solve the problem. Consider -

1) The woosh wasn't ever present with my old system - Weil McClain, Honeywell ZV on supply, B&G Pump, Expansion Tank on supply side, and it seemed to have alot of air issues (gurgles)

2) I am in my late 50's (equals light sleeper, early awake), and the whoosh will wake me up on the second floor on the other end of the house from the boiler in the basement. Must be travelling in the pipes. My friends have said "what the he]] was that?"

3) It also seems, the farther from the boiler you are, the more the sound is omnidirectional. I'll play with anchoring the pipes close to the boiler (per Harvey). but since it's any 2 zones.....

4) Reason for 1" and 3/4" - House was built in 1960, entire system was 1". It was quite beat up from families in 1990 when I bought it, and as I gutted each room, I replaced the radiators with 10+ coats of paint with new, and my supplier only had 3/4". I was not going to replace the 1" that ran through the floors (obviously).

5) mark, I am confused by your numbers, you list "speed three" at 7/4.5/4 GPM, and "speed one" at 3.85/2.42/2.16 GPM, then state that at speed one, the pump is producing high GPM/low head, producing a warning. From the numbers, it seems that "speed three" has the higher GPM numbers??? Also, is speed one "high" or "lo"? I need to know to not use the setting that causes the warning.

This problem is a warranty problem of the small family owned company that installed the system. Very good people, high integrity, years of experience, but they are a 2 people operation and seem perplexed with the short time they spent, especially at that time I didn't know how to replicate, Also they are absolutely hammered with work in the winter. I told them I would try to find out how to replicate (done), and since I have read and learned a ton on this board (and others) for years, and love solving problems, I started searching, reading, reading, I thought I would join and post this challenge.

It seems to me it's just not right. I could ask them to put on a spirovent, would it solve? who knows. Expansion tank to supply, pressure differential bypass (per Allan), etc. all who knows. All of these "maybes" are allot of work as you guys know.

If anyone has any additional thoughts, please let me/us know, in the mean time, I need to go buy some bricks!
Cheers;
Jim

Mark Eatherton

Redrum said:

Hi Mark and all;
Thank you, thank you X 100 for your thoughts, time and effort. But, I don't see options to solve the problem. Consider -

1) The woosh wasn't ever present with my old system - Weil McClain, Honeywell ZV on supply, B&G Pump, Expansion Tank on supply side, and it seemed to have alot of air issues (gurgles) The old system had a low head high GPM circulator. Honeywell valve are a seat and free ball type of valve. The ball is on an arm that is spring loaded to close. It closes off against the incoming flow, rather quickly, so the Hiss is real quick.

2) I am in my late 50's (equals light sleeper, early awake), and the whoosh will wake me up on the second floor on the other end of the house from the boiler in the basement. Must be travelling in the pipes. My friends have said "what the he]] was that?"Yes, water is an excellent carrier of noise, and if the pipes are tightly bound to the framing, then it acts like a speaker, causing the sounds to be very pronounced.

3) It also seems, the farther from the boiler you are, the more the sound is omnidirectional. I'll play with anchoring the pipes close to the boiler (per Harvey). but since it's any 2 zones.....If you can isolate the piping from the framing using black pipe insulation it might help. Sound is a very subjective situation.

4) Reason for 1" and 3/4" - House was built in 1960, entire system was 1". It was quite beat up from families in 1990 when I bought it, and as I gutted each room, I replaced the radiators with 10+ coats of paint with new, and my supplier only had 3/4". I was not going to replace the 1" that ran through the floors (obviously).Even back in 1960, the pipe, if sized by a professional would only have needed to be 3/4" As I said, someone probably "found" a bunch of 1" copper that "fell off the back of a truck (winky winky)", so the installer got a good deal. Nothing has changed as it relates to flow requirement and pipe sizes, they've have been the same forever.

5) mark, I am confused by your numbers, you list "speed three" at 7/4.5/4 GPM, and "speed one" at 3.85/2.42/2.16 GPM, then state that at speed one, the pump is producing high GPM/low head, producing a warning. From the numbers, it seems that "speed three" has the higher GPM numbers??? Also, is speed one "high" or "lo"? I need to know to not use the setting that causes the warning.If you will look at the performance curves for this circulator, they are shaped such that the ideal operating point is in the middle 1/3 of the curve, or what is called the knee of the curve. The pump can be operated in the upper third safely, but if you push it to the lower third, the motor is being subjected to a higher amperage draw because it is doing more work. It's not a dangerous situation, but its not ideal either. The key here is low head. In other words, there is little resistance to flow, so the pump is flowing a LOT of water Motor would probably run hotter in this position than in another position.

This problem is a warranty problem of the small family owned company that installed the system. Very good people, high integrity, years of experience, but they are a 2 people operation and seem perplexed with the short time they spent, especially at that time I didn't know how to replicate, Also they are absolutely hammered with work in the winter. I told them I would try to find out how to replicate (done), and since I have read and learned a ton on this board (and others) for years, and love solving problems, I started searching, reading, reading, I thought I would join and post this challenge.Kudos to you for doing their homework. Most homeowners wouldn't know where to start.I didn't really look into the PONPC versus pump locations because this system isn't a high pressure drop system, and that is where having the pump in the wrong place causes problems.I also didn't do all the math I could have. To determine the "required" flow, take the linear feet of baseboard per zone and multiply times 500 (BTU/linear foot). Then take the results of the equation and divide by 10,000. this will tell you how many GPM are required to maintain a 20 degree F differential across that loop. If the flow is greater than you need, then you can expect a lower temperature differential, which equates to a higher mean temperature differential across the convectors which is fine and acceptable, provided that hydraulic noises are not an issue. 1 GPM typically shouldn't be run at greater than 8 GPM, so you are well within the confines of the pipe.

It seems to me it's just not right. I could ask them to put on a spirovent, would it solve? who knows. Expansion tank to supply, pressure differential bypass (per Allan), etc. all who knows. All of these "maybes" are allot of work as you guys know.Unfortunately, your heating contractor fits the profile of about 90% of the people out in the field doing this kind of work. Great folks, and competent pipe fitters, but they have never taken the time to learn as much as they should have, or they would have performed all these calculations like I did and know exactly where they stand. They are essentially parts replacers, and not true hydronics technicians. If they had know what they were dealing with, they would have used 3/4" zone valves instead of 1", but they saw 1" pipes and decided they had to match what was there physically, instead of looking at it from the true demand/flow required and size accordingly. I have done research and have found that a Spiro type of microbubble resorber only can lower the O2 content of the water to the same point as the conventional scoop you have in there now. In other words, the Sprio will remove the air faster, but under the same circulation conditions, the scoop will do essentially the same. One old trick that has been used over the years for problematic air is to put a couple of ounces of liquid dish detergent into the system (Dawn is my preference, the blue stuff, not the pink stuff). It causes bubbles in the system to agolomulate (become one) and becomes easier to expel at the air scoop/vent assembly.

If anyone has any additional thoughts, please let me/us know, in the mean time, I need to go buy some bricks!
Cheers;
Jim

As I said, and I am a BIG fan of Taco products, it is the nature of the beast. A ball valve style of valve pinches the flow off such that it is noisy when its coming to a halt, as opposed to the Honeywell style valve of a ball on an arm that closes off against the stream to a round seat. And thanks for supporting the neighborhood. Going back to the Honeywell valves will take you back to the original control valve situation. I didn't run the numbers with the Bell and Gossett series 100, but can just for reference.

Jim, my response is nested in your original message in bold.

Paul48

What type of thermostats are you using?

Mark Eatherton

Jim, the series 100 would have been moving 10.3, 6.5, and 5.77 GPM (basement, main and top floors respectively).

If I close off the basement, main and top floor see 7.98 and 7.08 GPM.

If I close all but the top floor, flow is 7.68 GPM.

If I run only the main floor, flow = 8.61 GPM.

Running basement only = 13 GPM, which equates to 5.08 feet per second velocity in 1" pipe. Right on the naked edge of hydrolysis (Erosion corrosion), which you DON'T want in your system.

As you can see, your old reliable beater pump was capable of moving a lot more flow than the little pump you have in there now. If you'd had the valves you have now with the series 100, the noise would be even worse than it is now.

It keeps coming back to the nature of the rotator ball type of valve and the hydraulic hiss associated with closing off flow...

Based on the amount of baseboard you have, and I'd seriously question whether IT is the right size or not, but if the house has remained comfortable, it HAS to be enough, the load equivalent based on a 20 degree F differential between supply and return would be .8 GPM for the basement, 2.15 GPM for the main floor, and 1.8 GPM for the top floor. This is what is defined as overkill flow (existing) in our business, and is unfortunately rather common.

The issues with slow velocity and air hang up are real, but if the system is properly purged, and treated (Dawn) you can most probably choke the flow WAY Down, and it will work just fine. The noise may still be there, but should be less pronounced.

I think I'd try that before going into wholesale parts replacement.

You will most probably have to choke one of the pump isolation ball valves to about 90 to 95% of it throttle range, and can actually adjust it based on temperature differential (20 degrees F) between the supply and return with water going out at 180 and coming back at 160 to get you close.

Got questions?

ME

Redrum

Hi Paul - three big zones are Honeywell Th6000 series, the panel radiator zone is a Honeywell RTH2300.

I had wondered if it was possible to slow the zone valve closing that might be something to try. But, the stats are on/off.

Hi Mark - yes, I will have some questions, but I need to do a little research, and more testing first so I can be as intelligent and helpful as I can when I respond. I'll need a bit of time as I have to run right now.

However, I will say that the "whoosh" is not normal, it's not a hiss, or a grind, and it can be LOUD. I have had hot water baseboard heat since I was 3, and have loved and lived with it, and tinkered with it for 55 year, but if I had to live with this, I'd do forced air next. It's that bad. . Like I said, people sitting in my house, with music or the TV going, and everyone talking, have said "what was that???!!" So, it's not normal.

I love the $ savings of the new system, both gas and electric, I love the quiet operation, then WHOOSH! less love

In the end, it's the contractor's problem to solve, but I would much prefer to "solve" it for them and be able to say "do this", that's why I am going to keep plugging.

Again, can't say enough about all you guys. After all of this, I won't be a pro, but will have so many posts that if I respond to try to help others, they will think I'm legit!

cheers, Jim

Paul48

I do Mark...........If I read you correctly, you are saying the noise is being created by velocity change at the closing zone valve? Doesn't that also indicate a pressure change at that point, and is there a way to cushion that? Just thin'in