Heating pipe banginbg or other heating system system banging, clicking, tapping and creaking noise diagnosis and repair questions & answers.

This article series diagnoses Banging Noises at the Steam Boiler, pipes, or radiators. Banging radiators, clanging heating pipes, bubbling noises, creaks, hisses, pops, and the like are diagnosed & fixed by these procedures.

Diagnostic FAQs FOR Steam Heat Piping or Radiator Banging

These questions & answers about banging or clanging radiators or heating pipes were posted originally

at BANGING HEATING PIPES RADIATORS - topic home, where you will find description of different sources of and cures for banging and clanging noises in different types of heating systems including hot water heat and steam heat.

Our heat is making banging pipes after a popped Pressure Relief Valve

Have a 25 year old hot water boiler in basement of 2 story house. 150K BTU unit. Aquastat is Honeywell L8148A.

Recently had issues with unit "popping" the PRV. Technician replaced a number of parts, and all was working fine, until recently when knocking in expansion tank was noticed.

This was followed by banging in water pipes and again "popping" of the PRV. technician found the Automatic filling valve at 0 #s and the high limit on the aquastat above 210 degrees (don't ask me how either got set that way), but that's what he told me. He reset autofill at 7#s and high limit on aquastat at 150 degrees.

I now have the boiler cycling between 140 and 150 degrees, no hot water making it to the upper floor, minimal heat to the main floor and limited hot water (I've a 41 gallon hot water maker fed by the boiler).

From what I'm reading above, seems I should take the incoming water to a minimum of 12#s and move the high limit to 180 degrees? (Dec 3, 2015) Jeff B

Reply:

Jeff:

I suspect debris clogging; see details at BANGING HEATING PIPES RADIATORS

Watch out: see our safety warnings at RELIEF VALVE LEAKS

Our explanation of how and to what level you set boiler pressure is at BOILER PRESSURE & TEMPERATURE SETTINGS

 

After I drained water out of my steam boiler the boiler began surging

I drained (about 20 gl of water) my steam boiler as was recommended by a plumber, and all of a sudden that day water started to surge in glass gauge and one of the radiators in the house started spitting water and hammering. Any recommendations? Tks! On 2017-01-14 by Sam S

Reply by (mod) - Causes of surging problems in steam boiler

Surging can be a problem in steam boilers, Sam. And indeed surging steam boiler water can be a cause of banging sounds in the steam heat system.

You don't say why draining 20 gallons was recommended by "a plumber" - this sounds plausible but perhaps a bit arbitrary as I will explain.

We do not normally "drain" steam boilers unless as part of boiler cleaning.

We DO normally and frequently, perhaps weekly, flush the low-water cutoff valve (LWCO), a critical safety device that requires flushing to avoid debris-clogging inside the valve. That process will remove some water from the boiler along with sludge and crud from inside the valve body.

When water is drained by the LWCO flushout makeup water must be added to the boiler. Typically water is restored by an automatic water feeder valve though on some steam boilers water may be added by opening a manual water feeder valve instead (not a great system).

If your boiler failed to add enough water you might see surging.

The most-common cause of surging in a boiler is too much sludge, dirt, rust, debris in the steam boiler. Experts call this steam boiler problem "priming", and you'll see the water in the boiler sight glass bouncing up and down - a problem distinct from "foaming" - the presence of foamy bubbles that might be seen in the boiler sight glass. (Foaming may be due to boiler water that needs treatment to reduce a too-high pH or alkalinity.)

That might be a reason that a boiler has to be drained and cleaned.

Just arbitrarily "draining some water" from a steam boiler is not sufficient in my OPINION - though I'm no Dan Holohan. But draining an arbritrary amount of water to flush debris from the boiler itself (through the boiler drain not the LWCO) might not work.

Instead you may need to drain water until the water coming out of the boiler runs pretty clean, re-filling along the way as needed.

You might have to do this several times as more sludge-crud may be returning to the boiler from the steam radiators by way of the condensate return line.

Watch out: it's best to do large-volume boiler flushing when the boiler is cool or cold. Running a lot of very cold water into a very hot boiler (steam or hot water boilers both) can cause thermal shock that could crack the boiler - destroying it.

A very thorough and detailed article on steam boiler foaming and surging, listing additional causes and cures was penned by Dan Holohan at heatinghelp.com - an independent website not connected with InspectApedia.com. Mr. Holohan's article is at https://heatinghelp.com/systems-help-center/reasons-why-the-water-is-bouncing-in-the-gauge-glass-and-where-to-look-for-solutions/

Advice for curing clanging steam heat pipes?

the riser in one room comes on tinging for 2-3 hours, the heat person has come a few times to no avail yet,
now the other room has the riser clanging, opening the radiator valves has not helped, they all just clang!! any advice? On 2016-11-08 by judy

by (mod) -

Judy, did you try the cures we give

at BANGING STEAM HEATING PIPE NOISE CAUSE, CURES ?

What causes noise at steam radiators in off position

I want asking about if have sound air/steam in my heating radiator and a little bit warm eventhough on the position turn off ? What i must to do if like that? Thank you for your help. (May 19, 2011) dave

Reply:

If your steam radiator is turned "off" at its local radiator valve but it is still getting warm, then the radiator valve is not fully closed. It may be that the valve needs to be replaced.

If your steam radiator valve is turned "on" and gets warm normally but the steam vent on the radiator never stops hissing at all during the heating cycle, then the steam vent itself may need replacement - a simple and inexpensive repair.

 

What's causing a slapping sound at heat pump

Our heat pump makes a loud slapping sound at various times. I don't think it makes this noise when the motor is on. (Dec 5, 2011) carolyn garza

Reply:

I'd look first for a loose fan blade at the condensing unit

Why did we get banging heating pipe noises after we turned our heat back on?

Cape Code style home built 1950's- 1 pipe system- exactly as shown at BANGING HEATING PIPES RADIATORS . 1 1/2 years ago new boiler/burner and pipes to and from boiler/burner to radiator(s) pipes replaced. New bleeder valves ( left in open position) installed on radiators. 1st season( last year) all appears fine, until end of season when loud bangs could be heard.

Shortly thereafter, heat was off for summer. No seperate hot water heater- burner ran over summer only for hot water.

No banging to be heard. Recently turned heat on. Within 10 minutes heat coming from radiators and LOUD banging began. Turned off thermostat. Hour later turned heat on, In attempting to pinpont location of bangs,observed water flowing down basement wall, at point beneath an upstairs radiator.

Turned off thermostat- checked water level in glass tube = full and dirty. 1st plumber drained bolier, water level back to 1/2 mark.

Approx 6 minutes later, all appeared ok. Plumber left. Within few short minutes discovered water spewing out from bleeder/seeping from pipe (leading into radiator-see photos in BANGING HEATING PIPES RADIATORS pipe bottom right-from floor into radiator ) on radiator located above where water was discovered flowing down wall in basement.

Turned off thermostat- called plumber who advised I seek steam experienced plumber. Next day, with thermostat off, water tube was again, filled to top- water clean in appearance. Next plumber came in, again drained boiler until water in tube was at 1/2 way mark.

Without turning heat on, plumber's assesment is pipes from burner/boiler to radiators are not angled correctly. Advises pipes be removed and reinstalled at correct angle. States job is very labor intensive.

Question. If plumber is correct, culprit = current position of pipes, why issue now and not last season? Desperate for assistance. Fearful to turn heat on and very cold here= fearful of pipes freezing. Extreme difficulty in finding experienced steam heat plumber. Any and all suggestions greatly appreciated! (Nov 9, 2012) Prudence

Reply:

Prudence, you might search InspectApedia for "Banging radiator pipes" or Banging Steam Pipes for more diagnostic details;

in general I suspect a condensate return problem. Indeed if the boiler changeout changed the slope of a condensate return pipe ANYWHERE in the system that will often cause a condensate return blockage - condensate needs to return to the boiler by gravity.

If your plumber can point to improperly sloped pipes it sounds to me as if s/he's on to the problem and probably knows more than either of us.

 

What causes banging copper pipes when the furnace pumps hot water thru pipes

Within the last 3 months our copper pipes makes a loud banging when the furnace pumps hot water thru the pipes. Tried draining, didn't help. Have a filtration system that doesn't seem to be involved. For 18 yrs. there was no problem--no recent alterations to the system. Would appreciate any suggestions. (Sept 25, 2014) Patricia Kimball

Reply:

Look for blocked condensate return or radiators sloped the wrong way.

 

To Fix loud banging pipes when the heat kicks in - can I insulate the radiators to control the noise?

I live in new York with a steam pipe and radiator system. I'm going into my 3rd winter here and when the heating kicks in, the pipe bangs loudly and sounds like someone is hitting it with a hammer.

I think this is water hammer. the building has 36 apartments and they aren't willing to do anything. they've checked the radiator and pitch is ok. It's the pipe and they system that is probably old and dirty. This wakes me a disturbs my sleep many times a night and made me ill last year

I've written to the landlord many times and even withheld rent last year. It hasn't helped. I'm worried about it happening again this year and may have to move out. I wonder if there is any type of lagging or soundproofing you can recommend for the pipe that may help to reduce the noise. I'm desparate! Thanks (Oct 3, 2014) Emma

Reply: unlikely

Emma

I am doubtful that insulating steam heat radiators or piping is going to be a happy solution to banging pipes - as it risks interfering with heat transmission; more likely what's needed as a steam heat tech to diagnose and fix the banging pipe cause.

 

Boston building: what's the role of the condensate reutrn

I live in an old(over 100 yrs) building in Boston. One boiler for 6 apartments in 3 floors.

Our steam heating is one-pipe system. What is the role of the returning water from the radiators to the boiler operations? If one apt wants less heat and uses the regulated vent to obtain it, more heat will go to the above apt which can do the same process and more heat will flow to the whole building. Are they helping save money as the heating cycle could be shorter? (Nov 4, 2014) Luiz G

Reply:

Condensate in a steam heat system returns to the boiler to be heated again into steam to provide more heat. If we didn't get rid of condensate from the radiators they'd all stay cold as water would prevent steam entry; if we didn't return condensate to the boiler it'd use more water than necessary, speeding boiler corrosion, reducing boiler life.

Luis the condensate returns to the boiler to be re-heated to make more steam. If no condensate returned but say were dumped into a drain the boiler's water usage rate would skyrocket as would the heating cost while the life expectancy of the boiler would diminish.

 

Is loud heating bangs in Marshfield Wi a wiring question?

I recently moved into a house in Marshfield WI. If I had to guess the age of the house I'd bet it's at least 60 years old (many of the rooms have 15A breakers installed which would originally have been fuses...and suggest 12-grade wiring).

The house was converted to an upper and a lower...presumably as cheaply as it could be done. It is using water radiated heat which is heated by gas.

Every time the heat comes on, within a minute loud pangs and sometimes rapid not-so-loud (like a cooling car radiator but louder) sounds come from the area of the radiators themselves. The landlord is an aged man and whenever I have brought up things that need to be done (such as better breakers) I get told to do it.

That said, what options can you suggest in order to alleviate such loud noise? I live on a fixed budget, so I cannot afford expensive remedies, but I would like to be able to do something about this. (Nov 6, 2014) Adariou

Reply:

Adarious

15A circuit breakers would normally be paired with #14 gauge copper electrical wiring. #12 copper wire (which would be fine) would support a 20A circuit.

Of course if your wiring were aluminum then the rules change and you'd see #12 aluminum wire on a 15A circuit.

That has nothing to do of course with banging noises. Our best advice on reducing banging radiators and pipes is in BANGING HEATING PIPES RADIATORS

 

How do I cure banging maching gun noise at heating system where radiators have electronic control valves?

I have a central heating system working on a control system . All the radiators have electronic actuators to control the temperature , these fit on the top of the thermostatic rad valves.
The heating has started to bang very very noisy as if there was a maching gun going off.
Anyone got any ideas? (Dec 4, 2014) Marti

Reply:

Martin do any of the banging pipe explanations in the article BANGING HEATING PIPES RADIATORS suggest help for your system?

If not, tell me what's changed since before the banging.

How to fix moaning whining noise from the cellar

(Jan 7, 2015) Annie Keller said:
I have an old house with radiator heat. I've been having a moaning, whining noise coming from my cellar, my brother says it's not the water heater, it's the boiler. It only happens when the winter temp gets to a certain coldness, the colder it is outside, the louder and more consistent the whining is.

I say maybe the boiler can be insulated to avoid the noise, my brother says the boiler can't be insulated. Who's right? Thanks ahead of time for any input you may have.

The whining is coming from the cellar - from the actual boiler itself, not from individual radiators in the house. The whining only happens when the temp outside gets to a certain low and the colder it is outside, the more and louder the boiler whines. Not sure how individually regulating radiators would solve the problem in the cellar.

The radiators themselves are working perfectly fine. Is there such a thing as boiler insulation or a boiler cover to keep the boiler from frigid temperatures in the cellar? It's an unfinished cellar with no heat. Thanks for your response ahead of time....

Reply:

21 Feb 15 susan said:
Check that your pipes are firmly hung. My pipe was drooping cuz a pipe holder let go .Major banging occurred.

 

Loud banging noise 15 minutes after the thermostat kicks the boiler

I have single pipe steam radiators in my house, and just this winter, the radiator in the bedroom started making very loud banging noises about 15 minutes after the thermostat kicks the boiler on.

It wakes me up nearly every night. I took a level and made sure that the radiator is pitched appropriately. I also make sure the valve is open all the way, and I cleaned the vent with vinegar, and it seems to be releasing the air just fine.

The bedroom is on the first floor and sometimes the pipe beneath the floor sounds like someone is hitting it with a hammer, and it's enough to shake the floor. I called my plumber, and he said that it's not likely that this is something that can be fixed. He said he could spend a lot of time troubleshooting and still not find the cause. Any ideas on what the issue could be? Thanks! 26 Feb 15 Cathy

Reply:

We discuss the typical causes of banging steam pipes in BANGING HEATING PIPES RADIATORS. I don't have better suggestions; your plumber is doubtless correct: the problem can be fixed given correct diagnosis. Usually people start by looking for a blocked condensate return.

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Continue reading at BANGING HEATING PIPES RADIATORS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see BANGING HEATING PIPE RADIATOR FAQs-2 - more recent Q&A about solving banging tapping or clicking noises at heating systems

Or see these

Heating System Banging Noise Articles

• BANGING HEATING PIPES RADIATORS
  • NOISES TRACED to HEATING EQUIPMENT & PIPES
  • STEAM RADIATOR BANGING if SLOPED WRONG WAY
  • OTHER CAUSES of BANGING STEAM HEAT or POUNDING RADIATIR NOISES
  • STEAM PRESSURE ADJUSTMENT, BAD ADVICE
  • BANGING STEAM HEATING PIPE NOISE CAUSE, CURES
  • BUBBLING GURGLING SOUNDS in HOT WATER HEATING PIPES
  • CREAKING CLANGING HOT WATER HEATING PIPES
• BANGING BOOMING NOISE DIAGNOSIS & CURE - home
• BANGING HEATING ZONE VALVES
• BANGING NOISE at AIR HANDLERS or in DUCT SYSTEMS
• BANGING WATER HEATER
• BANGING WATER PIPES
• GAS BURNER FLAME & NOISE DEFECTS
• GAS BURNER SOOT CAUSE & CURE
• GAS BURNER PILOT LIGHT PROCEDURE
• GAS IGNITER DIAGNOSIS & REPAIR
• NOISES COMING FROM WATER HEATER for the diagnosis and cure of clanking or thumping noises that may be coming from your water heater or heating boiler.
• PUFFBACKS, OIL BURNER
• SOUND CONTROL for PLUMBING for an extensive list of causes and cures of building plumbing noises.
• THERMAL EXPANSION of MATERIALS
• WATER HAMMER NOISE DIAGNOSE & CURE for other banging pipe noise diagnosis help

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