Whistling boiler pipes

Britboy

Moved in to new house. Boiler in basement. 3 floors incl basement. For 5 months all good but now whistling sounds coming from copper pipes that come out of the boiler and annoying us in our living room. Plumber who installed it said nothing is wrong but we def think there is a problem. Maybe air trapped or pump faulty. When we turn pump down, whistling stops but then the heating doesn’t work!
Any ideas welcome, please

Intplm.

Noise from here is very tough to diagnose. That being said, often the noise that you describe can come from a circulator or pipes resonating through the house or both.

Has there been before and after the noise work done on the system? Was insulation removed or added that could have been muffling noise between wood and pipe(s)?

Does the noise happen on every zone?
Turning thermostats down all the way then bringing up the temp all the way one at a time might help to narrow things down.
Turn one up all the way. Let it run, and listen. Then turn that one down all the way and repeat the sequence until you find a zone that is causing the noise. This should help to narrow things down.

Britboy

Thank you for responding. No insulation has been removed. I have found 4 pipes that send a constant whirring sound thru to the lounge upstairs, 2 coming from the tank and 2 from the boiler. I also turned heat right down and up but noise was constant

these are the 4 pipes, the ones with insulating rubber at top (i added). i am wondering whether to spray insulation foam up there, between floor and ceiling 

Intplm.

Some type of barrier should be used where pipe touches the wood, or anything else for that matter. Deadening the sound and eliminating this possible vibration whistling noise.
Im going to hazard a guess and say the problem is just above the sheet rock.
The process of elimination. One step at a time till you find it.

When the noise is heard, push on the pipes one at a time to hear if the noise changes. Be careful they could be very hot.

You can use a stethoscope if you have one, or use a long screw driver with the handle against your ear and the other end on the pipes.

Intplm.

Another thing to check is the copper pipes rubbing against the plastic pvc pipes. Look there.

Kvac13

btu on the boiler? Is the ups15 enough to meet the gpm for that boiler. I know that pump makes about 14-16 gpm at around 2-3ft which is what some high efficiency boilers are rated.

MarkMurf

Does the piping adhere to a proper primary/secondary loop design ? Is the delta T within proper parameters ? 🤷‍♂️

Lance

Noise in plumbing can be from anywhere and not always does the sound come directly from the source where water is involved as it flows quickly through water. While I have found velocity of a circulating pump to be too fast to cause noise, it was only resolved using a slower velocity pump. Often in properly sized pipe system using a 1725 RPM these pumps get replaced with the new 3450 RPM pumps and there's your noise source. But wait, just because you think it's from the heat system it may not be. I have found noises, especially the high pitch noise, to come from a leaky ballcock in a toilet. The sound was thought to be at one end of the house and turned out to be at the other end. If the pumps are off in the heat system and the noise persists it could still be a hidden leak allowing water feed. So, when testing make sure the auto water feeder is off. If you can turn the sound on and off, you can narrow the source down. Very unlikely, but we have traced plumbing noises coming from water meters outside the house. If it is in the heat system, with 3 pumps, you may need to vary the cycling and or find a restriction or possibly a valve that seems open but is almost shut like on a broken radiator valve. Also, washers in valves can come off and move to make a restriction, making a noise.

4Johnpipe

Doe the pulps have IFC? It should be marked kn the back face.

there may be debris from the okd system hanging up in the internal flow check devices.

Stet

Check with the manufacturer. I believe this model does have a problem (in some cases) with the intake air to the induction blower. They do have a part which is supposed to remedy this. If your getting the noise when the blower/burner is on, then go that way. If not, check internal pump.

scott w.

I also have an irritating noise when a pump is running that I can hear on the first floor from the basement below. Had some changes made in the system so hot direct hot water tank and loop was moved. Copper heating pipes were moved as well and one copper pipe crosses over another coppper pipe and they touch each other. The Grunfos pump noise now is magnified and travels through the pipe and can be heard on the first floor.

EdTheHeaterMan

From the photos you have posted, it appears that your near boiler piping may be different from that of the factory recommendations, but it is difficult to actually see those pipes from the angles of your photos.

I am referring to the closely spaced tees that make up the boiler loop separation from the system loops. (Primary/Secondary) Primary being the one with the expansion tank so the system loops are on the primary.

The area circled in red on the photo and on the diagram I hi-jacked from the I/O manual is what is important.

If that short pipe is missing then you have the makings of a poor design and may be the cause of your noise. If that pipe is there, then the system is installed per the manual so you need to look at each of the pumps, one at a time.

With the system operating and all pumps are on (may not be possible if the DHW tank has priority) you should hear the noise. By disconnecting a wire to each pump: A, B, C, D, and E, one at a time, then reconnecting it and moving on to the next pump, you should be able to find the problem pump. This should be completed by a professional if you do not feel comfortable with 120 VAC electricity. (you may be shocked by the test results) 🤣. The noise should react within a few seconds of the source pump being shut down. Then the noise will restart once you reconnect the wire.

If this test does not show a pump as the source then the noise is from elsewhere

I added the low temperature loop to resemble your system, albeit the order of the branches are a little different, the function is still the same.

jamplumb

What about the distance between the T's on the primary/secondary connections? Looks to be at the most 3 1/2", can this cause noise issues?

Alan (California Radiant) Forbes

The installer gave you some nice isolation valves on the pumps. I would turn off the valves on the pump that's making the noise, remove the motor via 4 screws and check for any debris on the impeller or inside the volute.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1801702#Comment_1801702

So there is a connection in the red circle area? Then the near boiler piping is correct. It may have been two 90° Elbows, hard to see. but it could also be Two Tee fittings there. And you are saying the connecting pipe is about 3.5". That will not cause the noise. Those tees are supposed to be closely connected.