Multiple rapid banging during call for heat

forumpersona

I live in a 2 story/3 zone (one for the basement) 2700 sq.ft. home in CT. We moved in 2 years ago. During the 1st winter we saw that there was some banging in the pipes when heat was called for. Usually one loud bang followed by the baseboard fins pinging. Since it was a single bang we decided to live with it.

This past summer, we had some work done to the house where the main water supply needed to be shut off and pipes drained. This winter, the pipes bang a lot worse. We're talking about multiple bangs more like 5-15 of them in rapid succession as heat is called for. These bangs happen mostly in our bedroom which is the room furthest away from the boiler. There are some other bangs around the house but they are mostly the single bang kind.

We just had the boiler serviced by the oil company and everything came out ok. We mentioned the banging and the possibility of air in the system to the technician and we were pointed at some automatic vent valve that is supposed to auto-vent the air but I am not convinced. Too much of a coincidence that after we drained and refilled we got so much extra banging. Our system also has a gray expansion tank.

It is now interfering with our sleep because as it got colder, the heat cycles on and off many times per night. Any suggestions?

Thx

p.s. I checked the copper pipes for the baseboard and none of them have ANY room, it seems as if the wood was cut just enough to allow the copper to go through. I also checked all the pipes in the boiler room and they are all firmly attached to joists.

Ironman

This could be one of several possible causes that are too numerous to list. Also, more info is needed and there will probably be several questions that you'll need to answer.

Let's start with a couple of simple things:
1. What's the Cold static fill pressure? Look at the gauge on your boiler.
2. What's the pressure when the boiler reaches full temp?
3. Does it sound like it's coming from the burner, the circ, the piping or radiators?
4. Is there any water leaking anywhere?
5. Can you post some pics of the boiler, it's near piping, the radiators or where you think the noise originates?

forumpersona

1,2,5 I will have that for you tonight.
4. No leakage.
3. The noise is coming from right behind our headboard which is definitely no where near the boiler room. It's actually as far away from the boiler as possible. Completely opposite side of the house. It's a long row of baseboard back there. Below that is the dining room which has another long row of baseboard.

icesailor

forumpersona said:

I live in a 2 story/3 zone (one for the basement) 2700 sq.ft. home in CT. We moved in 2 years ago. During the 1st winter we saw that there was some banging in the pipes when heat was called for. Usually one loud bang followed by the baseboard fins pinging. Since it was a single bang we decided to live with it.

This past summer, we had some work done to the house where the main water supply needed to be shut off and pipes drained. This winter, the pipes bang a lot worse. We're talking about multiple bangs more like 5-15 of them in rapid succession as heat is called for. These bangs happen mostly in our bedroom which is the room furthest away from the boiler. There are some other bangs around the house but they are mostly the single bang kind.

We just had the boiler serviced by the oil company and everything came out ok. We mentioned the banging and the possibility of air in the system to the technician and we were pointed at some automatic vent valve that is supposed to auto-vent the air but I am not convinced. Too much of a coincidence that after we drained and refilled we got so much extra banging. Our system also has a gray expansion tank.

It is now interfering with our sleep because as it got colder, the heat cycles on and off many times per night. Any suggestions?

Thx

p.s. I checked the copper pipes for the baseboard and none of them have ANY room, it seems as if the wood was cut just enough to allow the copper to go through. I also checked all the pipes in the boiler room and they are all firmly attached to joists.

Sounds like the piper wanted to be a wood pecker and see what the smallest hole he/she could drill and still get the tube through.

I used to pipe/rough in second floor heat through a 1 1/2" hole in the subfloor, anchored so the pipe was centered to where it needed to be, and cardboard signs about leaving the pipe alone and to drill a minimum of a centered 1 3/8" hole, centered where the pipe was with a dimension drawn from the wall to the center of the 3/4" copper tube.

When I got there to finish, Woody had drilled a 13/16" hole, rasped out to tightly fit the 3/4" tube, and the pipe jammed up against the hole in the subfloor. Like Steamhead says, "You can't fix stupid."

Or, why you need big holes with lots of room for expansion for pipes. At least enough room to put a piece of metal for the pipe to slide on.


Expansion rate of copper tube:

1.1" per 100 degree rise in temperature per 100'.

Ironman

forumpersona said:

p.s. I checked the copper pipes for the baseboard and none of them have ANY room, it seems as if the wood was cut just enough to allow the copper to go through. I also checked all the pipes in the boiler room and they are all firmly attached to joists.

This sounds like your problem: no where for the pipes to expand when they're heated.

Especially watch out for the riser coming off the boiler: if it comes straight up, and the then turns horizontally, and has no room to expand upward, it can make some very impressive noise.

forumpersona

Here are some pics. The gauge one shows temperature and pressure. Heat wasn't on when I took the pic

forumpersona

This is the gauge with the heat running right before it ticked off.

billtwocase

I would say get rid of that funky air scoop wanna be. I don't think it is piped right. Federal boilers had one similar, and they were always banging and clanking. I would also have a 1/2 X 1/8 black reducing coupling and an Amtrol 700 on top of the boiler. I think a lot of your noise is flowchecks and other at boiler issues following that zone piping, also some pipe expansion noises as well. Pressure and temp look to be where it should be.

forumpersona

billtwocase said:

I would say get rid of that funky air scoop wanna be. I don't think it is piped right. Federal boilers had one similar, and they were always banging and clanking. I would also have a 1/2 X 1/8 black reducing coupling and an Amtrol 700 on top of the boiler. I think a lot of your noise is flowchecks and other at boiler issues following that zone piping, also some pipe expansion noises as well. Pressure and temp look to be where it should be.

Thx, isn't the Amtrol 700 similar to what sits above the expansion tank in my 2nd picture? Also, there's a watts s1156f visible at the top of the 4th picture.

billtwocase

Yes, the 700 is an auto vent. I have the best results with those. The 1156 is the auto feed.

forumpersona

So, any ideas as to why the pipes got a lot noisier after the water was turned off and back on? The boiler room is completely quiet, the noises are emitted by the pipes on the top floor it seems. I don't know if it matters but the colder it is outside, the louder the pipes are when the heat comes on. Would an outside reset help with keeping the pipes at a more stable temperature?

Thx

forumpersona

I looked at my AquaStat. It's a Honeywell 7224U. It was set at a high limit of 180 with a differential of 10. No low limit was set. I lowered the high limit to 170 and we'll see tonight if it makes a difference.

icesailor

If the house is old, and any weather stripping has been done, turn the high limit down on the boiler to 160 degrees. The water temperature is too hot, Also, you need to get the Low down to 140. You're sending really hot water out of the boiler and into the system.

Judging by the age of some of the antique fittings around your new boiler, you probably have a lot of steel pipe away from the boiler. Like in walls and under the house.

If you take a hammer and beat it on one of those steel pipes, and that sound isn't what you are hearing, you are not describing a "Bang" like we talk about. Like if you were describing the "Bang" in a steam system, many of the "Bangs" are preceded by a "SNAP/Bang".

That fill valve (WATTS 1156F) Cast Iron Valve, known to stop working when the strainer screen plugs up with rust. I believe they stopped selling Cast Iron valves and only sell brass ones for what the same price was for their CI ones. And never trust a boiler gauge.

You really need a professional that knows what they are doing.

forumpersona

Thanks icesailor. The Aquastat has an electronic display. When I chose 'bt' which is boiler temp it showed me 170 when the gauge needle showed a bit higher. The high in the aquastat was set to 180. I made it 170. The house was built in 1964. Typical New England Colonial. The boiler is not that new. It was put in in the early 2000s. Either 2001 or 2003. And, you are correct about the 1156F. Their manual says to clean the strainer twice a year at least. I don't know if the service/oil company bothers. What would the effect of a clogged 1156F be?

icesailor

Only on the pressure and the ability of the valve to maintain adequate pressure. I forgot that you have a electronic controller. They are very accurate.

I've been doing this since before that house was built. I've never ever seen a fitting like that on a boiler. I figured that it must have been installed in some Neolithic time.

But like I said, your "Bang" and the "Bang" of others here may not be the same.

Jets fly over my home when the wind is a certain way and they are landing at PBIA. They usually turn at about 1500' right over me. There is this very unusual sound that could be alarming to some who first hears it. I can't think of any way to describe it. But it is the sound of the landing gear coming down and an adjustment of the flaps for their approach. Its a "Bang" too. But it is a Bang like none I ever heard in a house. Not even close.

Depending on the Pilots and their procedures, some have done it long before they get over me, Some do it after me. Most times, I don't hear it at all. But I know what it is.

forumpersona

I will take a recording tonight. Maybe it will be diminished with the high temp at 170 instead of 180.

forumpersona

icesailor, is it possible they replaced boiler and left plumbing from neolithic times?

icesailor

Set the high at 160 degrees Set the Low (LO) at 120. Try it then, If the sound is less severe, its probably expansion.

Are you sure that the LO isn't set higher than you think? It sounds like the boiler is super hot (180 degrees) and the noise is hot water pipe expansion.

forumpersona

icesailor, I did not want to mess with the Lo as it is now set to OFF and the system depends on the difference setting which is set to 10. I think they did that because they have the indirect water heater attached to the boiler as a zone. I am assuming a difference setting of 10 would make the LO 170 when the HI is 180. Since I changed the HI to 170 the new LO is now 160.

forumpersona

Update, no improvement in the noise. Overnight the pipes were hammering as bad as before.

icesailor

forumpersona said:

icesailor, is it possible they replaced boiler and left plumbing from neolithic times?

Well, I was thinking more along to before that. The Pleistocene era when woolly mammoths roamed the savanna's of Siberia.

icesailor

forumpersona said:

Update, no improvement in the noise. Overnight the pipes were hammering as bad as before.

Set the Low (LO) to 140 degrees. It doesn't have to be off or set at 100. That's only to make it a cold start. In theory, being at zero, and a cold start, if the boiler gets a "call" for heat, and the boiler is cold, you shouldn't get any expansion noise until the water heats up. Leave it on zero and that WGO boiler will look like a pig after a good wallow in the mud in short time. And unless you have a quality soot sucker that can take the time to properly clean it completely, it will have a seriously shortened life.

If your "noises" are pipe expansion movement, they won't go away. You have to look for the places it rubs on wood and put something between the pipe and what it is resting on.

Abracadabra

forumpersona said:

Update, no improvement in the noise. Overnight the pipes were hammering as bad as before.

Take a video and put it up on youtube and someone will be able to tell you if what you have is hammer or expansion noise.

forumpersona

icesailor, so you mean do it just as a test and then put it back they it's set now, right?

forumpersona

Abracadabra said:

forumpersona said:

Update, no improvement in the noise. Overnight the pipes were hammering as bad as before.

Take a video and put it up on youtube and someone will be able to tell you if what you have is hammer or expansion noise.

Will do.

icesailor

When troubleshooting a problem, everything is "A Test" until the problem is identified and fixed.

Some call that a process of elimination. Like those ladder diagrams they give you to troubleshoot boilers and electronic controls so you don't have to call tech support and have that question. "Did you go through the ladder diagrams?"

forumpersona

Spoke to a local plumber on the phone. He agreed with you, he asked me to set the LO on the aquastat and see how that goes. He also said banging is probably the pipes on the frame not air. I will wait until tonight when it gets cold and I will also record the noises should they occur again.

Thx

forumpersona

I did that, set the LO to 130. The high is at 180. I also increased the High Diff to 20 (from 10). Now, the boiler goes on less frequently. The banging has decreased dramatically both in frequency and intensity (loudness) but it still happens and when it happens I get 30-40 in a row. It's possible that some of the requests for heat coincide with the boiler being at the high of 180 while the majority may come in when the temps are between LO and HI and just the circulator provide the heat. My wife is complaining that the house feels cooler although the thermostats in the house read the same temps as before. It could be placebo. I am thinking of lowering the HI to 160 and keeping the LO at 130 as a test.

icesailor

If the "Banging happens "30 to 40 times in a row", it isn't "Banging" in the true sense, it's pipe expansion. If the sound is in a wall, you're stuck. If it is in a ceiling, you're stuck. If it is below the first floor, you can find it where pipes rub on wood, or slide and bounce in wire hook hangers.

Your wife has developed a sensitivity to the whole situation and isn't going to be satisfied until what she thinks is the problem, is dealt with. If the High Limit was set to 70, and the house is getting warm and shutting off the boiler, turn the High back down to 170 degrees. If it still stays warm and shuts off, turn it down to 160 degrees. The cooler water will slow down the expansion noises. You can even try 150 degrees. If the boiler/burner isn't satisfied, turn the water temperature up.

forumpersona

Yeah, think the total number of banging noises in a row has increased with the changes I made but the frequency of the occurence has diminished. This banging used to happen every hour or so during the night. Now it happens once or twice but the number of bangs has probably doubled. from 20-25 to 40+ and the intensity of the noise is also less, it's not as loud.

Jamie Hall

Expansion noises. The spousal acceptance factor can be a real problem with them. So can fixing them. There are two ways to go about it -- both of which have been mentioned. The first is to keep the temperature change of the circulating water to a minimum. It doesn't matter what it is; what you want is to keep the swing as small as is reasonable. Outdoor reset can help a lot in tis regard, together with well controlled p/s piping and controllable (variable flow) pumps on the secondaries, or alternatively controllable mixing valves. The second is to find out as many places where expansion is restricted in the system and fix them. Anywhere where a pipe rubs going through a floor, for instance -- try putting a shim of plastic such as might be cut from a mlik jug so that the pipe isn't right against the wood. Loose pipe hangers in the basement -- tighten up. Too tight pipe hangers -- again, a shim of plastic may help. It's fiddly. Sometimes it is a radiator or length of baseboard -- again, try the plastic shims so they can more easily.

Sometimes it comes under the heading of "incurable, endurable"...

forumpersona

The upstairs piping maybe a total mess, I am not sure. There is one pipe that rises up from the floor into our bedroom. Then, the baseboard runs around the exterior walls (about 50% of wall) and continues into a closet. Comes out the other side into another bedroom. Runs the length of the exterior wall in that bedroom and then ends up in a 3rd bedroom. Goes around one exterior wall and then turns. Goes about 1/2 way the next exterior wall and then dives into the floor. So one long continuous baseboard occupies most of the top floor with 2 points going to the floor below. Is that normal?

Jamie Hall

"Normal" is a little hard to define -- let's just say I wouldn't have done it that way. But -- you could well have expansion noises in that big a loop, particularly connected with longer straight sections. Make sure that any elbows are free to move -- not locked up tight against a wall or something -- and try the plastic shim idea on every point that holds up a pipe.

forumpersona

Jamie Hall said:

"Normal" is a little hard to define -- let's just say I wouldn't have done it that way. But -- you could well have expansion noises in that big a loop, particularly connected with longer straight sections. Make sure that any elbows are free to move -- not locked up tight against a wall or something -- and try the plastic shim idea on every point that holds up a pipe.

There are only 2 entry points where pipes come out and the wood around the pipe is tight. No gap left to insert anything.

Jamie Hall

forumpersona said:

Jamie Hall said:

"Normal" is a little hard to define -- let's just say I wouldn't have done it that way. But -- you could well have expansion noises in that big a loop, particularly connected with longer straight sections. Make sure that any elbows are free to move -- not locked up tight against a wall or something -- and try the plastic shim idea on every point that holds up a pipe.

There are only 2 entry points where pipes come out and the wood around the pipe is tight. No gap left to insert anything.

And so... every time the pipe changes temperature, it changes length -- and will bang.

forumpersona

Is it usually horizontal movements that bang or vertical?

icesailor

Look at the holes are where they go through the wall. They should be large. At least 1 3/8" at a minimum.

On add on renovations, it is common to run through rooms on an upper floor to save the cost of busting out walls and ceilings. Sometimes, an installer will look for a closet in some inconspicuous place to go UP, and run through rooms to get to another inconspicuous place. Sometimes, you go "Wall To Wall" and only install active radiation inside the cabinets where needed. Then, you might run back on the element or under it.

When you take the front covers off the baseboard, there are supposed to be plastic slides that are clipped to the elements. The slides must be resting on a bracket. If not, they need to be moved. Each element slide should be centered on a bracket. If you need plastic for slides through wood, cut up a milk jug or water bottles. The plastic element slides are easy to move. Once you figure out how. Do it right, its easy. Do it wrong, it's harder. The whole thing should slide easily from left to right. If and when it does, most of the noise will go away.

Also, if it is old, they used oil to get the fins on. The oil dries out and makes a sort of "ticking" noise. Spray the elements with Silicone spray with a tube. It will smell at first, but it will get quieter.

Jamie Hall

And expansion doesn't care whether it's horizontal or vertical -- the forces are enormous, and the pipe WILL expand. If something is in the way, it will move it. If it is stuck on something, it will push until it is unstuck. And, most likely bang.

forumpersona

icesailor said:

Look at the holes are where they go through the wall. They should be large. At least 1 3/8" at a minimum.

On add on renovations, it is common to run through rooms on an upper floor to save the cost of busting out walls and ceilings. Sometimes, an installer will look for a closet in some inconspicuous place to go UP, and run through rooms to get to another inconspicuous place. Sometimes, you go "Wall To Wall" and only install active radiation inside the cabinets where needed. Then, you might run back on the element or under it.

When you take the front covers off the baseboard, there are supposed to be plastic slides that are clipped to the elements. The slides must be resting on a bracket. If not, they need to be moved. Each element slide should be centered on a bracket. If you need plastic for slides through wood, cut up a milk jug or water bottles. The plastic element slides are easy to move. Once you figure out how. Do it right, its easy. Do it wrong, it's harder. The whole thing should slide easily from left to right. If and when it does, most of the noise will go away.

Also, if it is old, they used oil to get the fins on. The oil dries out and makes a sort of "ticking" noise. Spray the elements with Silicone spray with a tube. It will smell at first, but it will get quieter.

Looking at this:

http://www.slantfin.com/images/stories/Homeowner-Info/baseboardinstallationinstructions_bbii.pdf

I don't see any mention of plastic slides. And, since the house was built in the 1960s,

I was also thinking of using my dremel with a flex shaft and a carbide tip to enlarge the area around the pipe.

I found this:
https://www.youtube.com/watch?v=r1ecdBTzbRE

I think that's the plastic you mention. I will take a look.

icesailor

That's the plastic slide. In the photograph the slide needs to be pushed to the right because the bracket interferes wit it sliding.

For long length like that, they have expansion joint fittings. They show them in the Slant-Fin PDF

forumpersona

I am going to take a good look at it tonight. Lowering the temps on the boiler has not made a huge difference. And, I am considering using the dremel around the pipe. Just nervous about nicking the copper.