Banging pipes wake the baby, and parents! Please help!

katedec

Hi everyone,
I'm writing to ask for your help with a heating issue. I've had a few people listen to it, but no one has solved it! We have natural gas boiler and I included a picture of its details as well as photos of our set up.
It started the first time we turned our heat on, 12 years ago. When the rooms get to temperature and the circulatory turn off, bang bang bang. We at first tried having the air bled from the system. No luck. Ever
y year ot two we have our furnace serviced, it's original to the house, and what rooms make the banging change. I didn't really care when it was downstairs, but we recently were serviced, and now it's in our bedroom! The person we had service the system said it must be loose pipes in the wall or the basement. My husband went through and added brackets in the basement, which were very few and far between prior. Didn't make a difference.
Also, I would think if it was just loose pipes, it wouldn't change where the banging is
heard!
I am desperate for help. We get very little sleep due to our 9 month old ba

by, so the sounds waking her and U.S., need to go!
Thank you, I am very appreciative of your time and suggestions!

STEVEusaPA

Banging noises can be tough to diagnose, but I have some questions.
Has anyone been next to the boiler when the circulator shuts off? If so, do they hear banging down there?
If it were just expansion noises, you wouldn't hear a loud bang right at shut down.
Pipe noise can radiant the sound anywhere, not just where the noise is generated (as you are now well aware).
It appears you have one zone with split loops (based on what I can see in the pics).
It's very possible that it just wasn't bled correctly. Another possibility is something with the circulator. I do notice the circulator and expansion tank placement is not following best practices. I also see the expansion tank right against another pipe.
If I were trying to diagnose this, I would would have one person cycling the circulator/boiler, and another go around and try to isolate the sound. I don't know much else to try.

kcopp

Besides not being piped right there is a flow issue.
That boiler is SUPER sensitive to flow. If it has poor flow or no flow it will hammer like nuts.
Where is this?

hot_rod

That type of boiler needs to have adequate flow any time the burner is on. The manual shows various piping options and pump size selections. That pump may be on the small side depending on the piping and heat emitters connected.

It is nice to use a post purge function on those pumps, it runs for a few minutes after the call for heat or burner goes out. So it purger all the residual heat out of the copper fin tubes inside the boiler.

If the boiler has limed up they tend to make a percolation sound, like an old tea kettle

Here is the manual the shows piping options and flow requirements.

http://www.laars.com/LinkClick.aspx?fileticket=dgUmqeBOU3w=&tabid=1998&mid=6436

katedec

Thanks everyone for your suggestions!
Steve, I had the furnace guy stay in the basement while I turned the heat on and off, he must have stood near the furnace and not notice anything. It's kind of a cheaply built house, so I not surprised that it was piped incorrectly. Is bleeding the lines something I could do myself? Or do I need a professional?
Kcopp, what do you mean by where is this? We are in northern New England! Cold, cold, cold! How can I have a flow issue solved? Is it even worth solving with this boiler?
Hot rod, how do I get it to do a post purge function? I was looking at the manual( thank you!) but it doesn't have instructions for how to do that, unless I missed them! Do you think that the boiler would have been checked for lime when it was serviced, or is that something I have to request?
We have a fairly small house, 1740 sq feet, and I thought we had two zones, though maybe it is just a split single zone, I don't know. We have two thermostats, so I figured there was two zones.
There's definitely some pipes banging, but I also thing there is something else, since it kind of fluctuates which heat vent the sound comes from. It also makes the little tinkling noise when heat starts to come through, maybe that's the old tea kettle noise? .
I really appreciate your comments and help! I'm so sick being annoyed by such a silly thing, but it's so loud that infrequent visitors are startled by it, and I feel like I should be able to figure it out!
Thanks again!

kcopp

What town...? there are folks here that may be able to help you out. That boiler was very popular install back in the mid/late 90's in Maine and New Hampshire.

katedec

Burlington VT.

Mark Eatherton

Can you give us a better picture of the pump, including model number. Also a better picture of the near boiler piping. Stand back from the boiler when doing so.

ME

katedec

Sure! Hopefully these are of some help! (And that I took a picture of the right parts!)


)

hot_rod

Copper tubes are great little boilers, excellent heat transfer with copper tuber.

They need to be checked and cleaned occasionally. If you see debris on the top jacket or the paint is discolored it could indicate the fin tubed need to be cleaned.

The tubes can also plug inside from hard water conditions, that is usually when you hear them percolate like the old tea kettle.

A mild acid cleaner will usually clean and fix the inside. The jacket needs to come off the top to check for plugged fin. Sometimes a mirror from below in the burner tray will give you a view of the fin tubes. Motorcycle mirrors are great for reaching in and looking up.

Here are some examples of copper tube boilers that needed a good scrubbing. These were run with low return temperatures that caused the corrosion and flue pipe breakdown.

Looks like someone has used a combustion analyzer based on the silicone patch above the jacket. That is a good way to check for burner operation.

A CO detector is never a bad idea in that room.

katedec

Any other suggestions? Copper tubes are clean. Anyone know someone reliable who can help diagnose and fix this?

katedec

Bump, anything else?

Abracadabra

As has been mentioned, you need to verify proper flow. It's piped incorrectly. Doesn't look like there's anyone near Burlington VT in the "Find a Contractor"

kcopp

@Tom is in Montpelier....
40 min up I-89.
Its a piping/ flow issue.
It should be piped primary secondary or at least w a bypass.

plumber1969

Also make sure the circulator is pumping in the right direction

Mark Eatherton

Well, unfortunately, as others have noted, it is not piped ideally, but I don't see anything that would contribute to a banging. Can you simulate these conditions during the day time? How many thermostats do you have? If you can recreate the banging, watch the pressure gage on the boiler. If it jumps commensurate with the banging, you need to have someone add a time delay relay to the pump to allow it to continue running after the burner has shut down.

Also, what kind of heating elements do you have throughout your home?

Sorry for being late in getting back here. Work got in my way...

ME

katedec

Ok. So we may have solved this. I had a new person come today to see if they could fix it. I had the circulator turn on and then forced it off by turning the heat down and immediately this person said, ok, I see the problem. He basically made the valves already installed (which were on the input side) stay open all of the time, and installed new valves on the return side. He also installed a new expansion tank, as he said it was pretty lose to needing to be replaced before he drained and refilled the lines, but after he did that, it really needed it.
I hope my explanation makes sense, but am not sure if I used the correct terminology!

Wellness

I am surprised the pros did not suggest this fix earlier. I've found that banging is frequently caused by copper radiator and supply pipes flexing and expanding as they heat up. Either constant circulation and/or a lower supply boiler water temperature can greatly reduce noise as will pvc bushings and proper hangars where the pipe emerges from the wall or floor. This is particularly true if the radiator piping is run on the perimeter of the house in the unconditioned space of floor joists where they can cool considerably between calls for heat.

NickDee

Hi - glad you have seemed to resolve your problem. Although just FYI --- I would hear noticeable vibration/banging when I turned on my main floor zone hear the last 2 winters... a few weeks ago it got much much louder then one day it was like a hammering sound and the circulator for that zone was dunzo.

katedec

Well, we will see I guess! There's an interesting evening crazy banging that happens now too, which seems to be completely another issue to me, I wonder if that may be the circulator. Hopefully it is all fixed though!

L Thiesen

Not heat related but that sump discharge is wrong. That is a code violation in my area, it should be piped outside not into the sewer line. If the sewer line were to stop up the sump pump would pump you know what into every fixture in the house and that would not be pretty.

katedec

Thanks L. Theisen. We're going to get that fixed.

My problems hasn't gone away! Well, part of it has, when the circulator turns on and off, everything is quiet! Yeah! But the crazy banging is not gone, just for some reason didn't happen last night. I ran down to look at the furnace when it happened and the pressure gage said it was up to between 25 and 30 psi and would kind of fluctuate. Then once everything quieted down it went back down to under 10.
Is that normal? Will a time delay relay, like Mark E. suggested, fix this problem?

kcopp

Again....Its a FLOW issue. There is not enough flow through the boiler when it fires just 1 zone. You need to at least pipe a bypass to keep the flow high enough. Seen it a bunch of times.