Heating baseboard (C) Daniel Friedman Heating Baseboard Repair FAQs
Diagnose & fix heating baseboards #2

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Hot water baseboard heat repair tips & troubleshooting FAQs Set#2:

Frequently-asked "cold heating baseboard" questions and answers help diagnose and fix hot water heating baseboard troubles in your building.

This article series provides common hot water heating baseboard questions and answers that will help diagnose & repair most common heating baseboard troubles including no-heat or leaks or other problems.

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Baseboard Heat Diagnosis & Repair Questions & Answers #2

Dirt dust clogged heating baseboard (C) D Friedman

These questions & answers about troubleshooting and fixing problems with forced hot water baseboard heat were posted originally at BASEBOARD HEAT.

On 2016-09-23 by Sanket Kudav: thermostat says no power to RH wires and no heat

So I have baseboard heaters at an apartment condo and the nest thermostat is giving me an error saying no power to the rh wires and the heaters are cold


Check that the heating system itself has power.

On 2016-07-09 by Sharon: need a baseboard end cap

I need to replace a missing endcap on a hot water baseboard heater. I am trying to identify the manufacturer of the baseboard. It looks almost exactly like the one in the first picture associated with this article

. Do you happen to know who the manufacturer of this baseboard is? If not, where can I look for identifying marks to try to find a replacement?


Sharon I have a brilliant idea:

Heating baseboard testing (C) Daniel FriedmanTake off another end cap from somewhere else on your baseboards - they just slide off and if you work with care you won't gouge anything.

Take that to your HVAC supplier and ask for a match.

On 2016-06-26 by Hott: how to turn off electric baseboard heat

How do I turn ofy base board heaters it 90 outside and 100 in my house



Your comment is on a page about electric baseboard heat.

If your electric baseboards won't turn off then one or more thermostats is not working properly, assuming you've already turned it to OFF. In that case turn off electrical power to the baseboards at the main electcrical panel - typically by flipping the appropriate (usually 240V double pole) breaker to OFF.

Then call for repair by a licensed electrician.

If you have hot water heat search InspectApedia for HEAT WON'T TURN OFF to read more details of cause and cure.

On 2016-05-26 by Debbie: smoky discolored walls over baseboard heat

Anyone know what causes a dark smoky discoloration on the wall, all the way across the top and the bottom (it's like that on most, but not all)?


Probably it's thermal tracking or ghosting. Search for those terms to read the cause, cure, and prevention.

On 2016-04-16 by Karen: smells from baseboard heat

I moved into a home that has baseboard gas heat. The heating system is about 1.50 old. There is a very bad dusty smell and the home is very dry and stuffy.

I cleaned all the baseboard heating vents but that did not help. The filter inside is new. I have been deathly sick because of this. Can anyone give me any idea what can cause this and how I can fix the problem?



Hot water baseboard heating whose water is heated by a gas boiler does not itself make your house dry, dusty, nor smelly. The odor is more likely coming from other components in the home.

Start by asking your heating company to confirm that the gas heater is operating properly and safely so that you can rule out a fatal carbon monoxide hazard; also be sure you have working CO detectors properly placed.

Then you can move on to tracking down the odor source(s) - search for ODOR DIAGNOSIS for details.

On 2016-04-13 15:44:55.388253 by Dianne: how to turn on baseboards

A few years ago I had my plumbing guy "shut off" the basement baseboard heaters. I did not watch how it was done, and now I want to turn them on but don't know how to do that. How is that done?


I don't know, Dianne as there could be more than one method of shutting off a heating zone.

There may be a separate thermostat for the basement zone: the plumber could have just disconnected the thermostat wires

There may be a zone valve that was disconnected from power and left closed

There may be individual shutoff valves on the zone piping, particularly if it was a parallel loop.

I'd start by looking for a thermostat for the basement zone.

On 2016-04-10 17:42:17.610224 by Robert: too much heat in summer

Informative site - thank you!

I live in a condo with a hot water heating baseboards. Heat in the summer months is always a big problem in the unit, getting roasting hot, and I notice that the heating baseboards are quite warm to the touch (although not scaldingly so - like traditional radiators can be).

The heat is on the middle section of the baseboad unit that has the radiator apparatus (metal sheets), and the baseboard is not hot where the copper piping is on either side of that.

This situation exists despite the fact that the thermometor is set to its lowest, and the baseboards are admittedly not pushing air out when the thermometer is set at its coldest.

Is this normal? Is there a way for me to cool down the baseboards further, so that they're cool to the touch, at least in summer ?



If your thermostat is not calling for heat but the baseboards are hot, then either there is a control snafu or

- there is a valve or control at the boiler that's manually open or stuck in open; it could be a zone valve or a check valve at the boiler that is allowing hot water to circulate by natural convection even when the circulator pump itself is OFF. Your condo association is wasting heating fuel if this is the case. No it's not normal. But cooling down the baseboards at your end is not a good approach as the underlying problems of energy cost and waste continue.

Ask your condo association to get help from an experienced heating service tech to find which control or valve is open that should be closed.

Keep me posted.

Reader Question about a Cold Baseboard Heat Room on a Single Zone - do I need to replace the aquastat?

2/13/2014 Question - Honeywell Aquastat Control Replacement  said:

Hi Just wondering if I'm about to get ripped off or should i tell this person not to do the work. I have a 1800 sq foot 2 story house and the farthest bedroom on first floor (2 outside walls) away from the furnace in the basement (consistently freezing cold outside) has been much colder than the rest of the house (tenants keep heat at 75 and this room hovers around 64-68)

It's a gas furnace - He told me its a Peerless Boiler and he is factory authorized dealer and the date on the boiler is May 2012. I have hot water radiator heat.

This new heating guy says the one year old Aquastat Control needs to be replaced - that it is a part failure unrelated to the workmanship of the previous contractor who did the work last year (i switched from Oil to Gas).

That if he repalces the control that there is a 70% chance that this will solve the coldness problem in the back bedroom will get warm. If the whole rest of the house has been warm without any problem - is this really the problem, wouldn't the rest of the house be cold too?

He wants to charge me $535 for the control 4 hours of labor at $65 an hour.

Now - its 2 days later, the room is still cold and now he's saying the baseboard heaters were installed wrong and need to be 'reworked' for $450. That they are upside down and this is why the room isn't warm (same original contractor who put in the new furnace put in these baseboards in last year).

I called the original contractor (wish i brought him over this time to begin with) but I'm working with a property manager now).

He says that what this guy is saying is not true - that they were put in correctly. It was me who decided to use a 4' shorter length on one of the walls and this could be the issue, but why then did this new guy have to replace the control for $795.

Do they really cost $535 or is that way high? Thank you for any help or advice anyone can provide. -Paula


Heating baseboards, typcial installation (C) Daniel Friedman

Really?  I can't make sense out of the explanation given by your service tech. The aquastat turns the boiler on and off, and may control one circulator. I can't see how it knows one room of the home from another. The tech may be honest but a lousy communicator, but from just the information in your note, I don't get it.

In the article above you'll see more photos of normal baseboard installations. I've never seen heating baseboard installed upside down - I wouldn't even know how to do that.

At left I have inserted a photograph of a normal hot water heating baseboard installation with the baseboards "right side up" and with decent clearance between the baseboard bottom and the floor surface. [We'll ignore for now that broken electrical receptacle cover hazard.]

[Click to enlarge any image]

Use the CONTACT link to send me some photos of your baseboards and we can comment further.

If you don't know what kind of heat your building uses, we explain how to figure out the answer

If your heating system is not working properly,


Question: mix up between hot water baseboard heat trouble, domestic hot water supply for washing bathing, and pump troubles that lose water pressure

I have a Hot Water Baseboard heating system in my mobile home. The other night a hot water faucet was left on slightly. It trickled out all night. This caused the system to run for over 8 hours straight. When we woke up we had no hot water. Come to find out the Water Heater circuit breaker tripped.

When I reset the breaker I started up the system and everything seemed to work perfectly...the heater fired up, the pipes got hot, the exhaust fan kicked on. But, no hot water was going to the faucets.

It does not appear that the circulatory pump was running. I replaced the pump two years ago when I moved in and it was working flawlessly. Is the pump bad or is some electrical problem happened that caused the circuit breaker to trip? - Conrad

Reply: a bit of clarification before diagnosis

We need to clarify the question as it looks as if you cite hot water baseboard heat and an electric water heater. Usually those are independent systems ... Or are you using a water heater both to make domestic hot water and also to run through your space heating baseboard ?

Question: the baseboard heat runs lack adequate clearance from the floor, blocking cool air inlet - how do we fix this?

I have inadequate clearance between the baseboard bottom and the floor surface - which blocks entry of cool air into the baseboard. What can I do to improve air flow without removing and raising the entire baseboard heater? - Dave

Reply: lack of air inlet at baseboard bottom cuts heat output and raises heating cost. Here's the cure:


I agree that if you block air inlet at the bottom of baseboards you are significantly cutting off the heat output of the system and thus increasing heating system operating cost.

Increasing floor clearance without having to remove and reinstall heating baseboard covers

If the blockage is due to wall-to-wall carpeting, you can try pulling back the carpet (with care to avoid tearing it) and cutting the carpet padding away for about 3-4 inches from and parallel to the wall where the heating baseboards are installed. Or remove the carpeting entirely up to an inch in front of the lower baseboard edge.

If there is no carpeting, and if air entry to the baseboard is blocked by wood flooring, I have to guess that someone added a layer of wood flooring atop the original - as it would be otherwise almost impossible to install the baseboard too low.

It might be possible to remove and replace the baseboard front cover with one whose total width gives adequate clearance from the floor- be sure that the bottom edge of the baseboard front cover protects the baseboard tubing fins from view and damage.

Too-low heating baseboard "fixes" to avoid

I would NOT "fix" this problem by leaving the baseboard covers off entirely. That mistake is ulgy, exposes the baseboard heat to damage, loses the convection effect of air movement up through the bottom and out at the top of the baseboard as designed, and risks occupants having cut bare toes that stub against the baseboard fins.

Similarly drilling holes in the baseboard cover loses the convection effects and prevents proper baseboard operation.

How to improve heat output & cut heating costs by raising heating baseboards that are too low

If the whole baseboard installation was made too close to the floor (check this by seeing if the bottom edge of the fins on the baseboard tubing is less than 3 inches from the floor surface (less than 3" is too close), then you have little choice but to relocate the baseboard installation higher on the wall.

The fix is an ugly one: one would have to

Question: I want to remove a section of baseboard

(Feb 14, 2012) Stacia said:

I have a hot water heating system with vents that run through the entire floor of the house. I want to remove a section so that I can install new kitchen cabinets (a completely different and more efficient layout) in its place.

Can i remove just one section and expect that the rest will run? Or can I cover them with something heat proof and place cabinets in front of them (built in, so to speak)? Also, this part of the house sits on concrete slab so digging out pipes to re-route would be very difficult and pricey.


You can cover over part of a heating distribution system with heat resistant materials without expecting damage, though you'll lose some heat output in the area.

Question: creaking baseboard sounds

(Mar 9, 2012) Damian said:

I have a hot water heating baseboard and it makes very loud pinging and creaking sounds. It is only in the one baseboard in our master bedroom. All other baseboards in the house make the normal crackling sound. I bled the line and the sounds are still happening.

Other than air issues, what else could be causing these annoying sounds?

(Jan 28, 2014) Noisy Baseboards said:

How do I reduce the noises, clicks, clanks of my baseboards?


Damian usually the heating baseboard sounds you describe are due to thermal expansion of the copper piping, perhaps combined with some binding of the piping where it passes through building floors or walls, or over mounts.

Try using a mechanic's stethoscope to see if you can track down exactly where the noise is occurring; Often placement of a small piece of heat-resistant plastic between moving surfaces or enlarging an opening for piping is all that's needed.


(Nov 7, 2012) Anonymous said:

im about to install copper fin base boards on a basement floor. which will have its on circulator pump. my question is can i connect three baseboards in series then return back to a return manifold?

also on some of the runs i will have to run 3/4 cooper up a wall in order to get over an object then back down to install the next baseboard. will this cause any problems?



You can certainly do what you describe.

We suggest including an air leader valve at the high corner of that section of raised piping

Question: how to reduce too-hot baseboard sections & send more heat to other rooms

(Nov 11, 2012) Reduce heat from fin-baseboards said:

We live in a building with heating loops, but no individual controls. While a loop can be shut down, if it is, no heat can be forwarded to remaining apartments. Each apartment has fin-based heat. Some apartments are way too hot in the winter, while others are just right, cool, or cold.

It seems to us that we need to reduce the heat in the "too hot" apartments. What is your advice? Cut fins off the system? Or somehow wrap the fins so they don't radiate heat (if this is correct, how would it be done?)


Typically people replace some of the finned copper baseboard with solid copper piping without fins to reduce heat output.

First be sure you've also tried just closing the hinged louvers at the upper or outlet side of the wall-mounted baseboard covers.

Question: Shouldn't there be warranties in place and incentives for the HVAC company to reinstall from the manufacturer?

(Jan 19, 2013) John E said:

We have two heating zones in our house and recently noticed that the zone for our bedrooms does not click on when increasing the temperature on the thermostat. The zone for the rest of the house kicks on instantly. what could be the problem?

(Feb 6, 2013) New Boiler blew out said:

I live at the Jersey Shore and had my hot water boiler replaced following Superstorm Sandy. Three months later, the new boiler has burned out. The HVAC installer is blaming the carpenters doing the work on my house because of too much dust. He is now seeking money from the general contractor and myself to replace the 3 month old boiler.

Shouldn't there be warranties in place and incentives for the HVAC company to reinstall from the manufacturer? I see nothing where dust can blow out a boiler, I only see writeups where dust can impede the efficiency. Any advice on this would be very helpful.

(Feb 21, 2013) Tommy Baseboard said:

just refurbished the oil boiler and the new pressure valve keeps blowing. the valve is rated for 30 lbs. but the boiler hikes the pressure up to 40 lbs. when it kicks on. How do i lower the outgoing hot water pressure? Any help would be's killing my mind.

Question: how to find the cause of noisy heating pipes

(Jan 29, 2014) Anonymous said:

We have an old house with horsehair plaster walls and woodenn baseboards. In the 1960's someone took out the radiators and nailed hot water baseboard radiators against the wooden baseboards. The problem is drafts coming in between the wood floor and the wooden baseboards. Because the hot water radiator covers are nailed to the wooden baseboard, we cannot reach the drafts to caulk them.

The nails made taking the covers off not an option. The wooden baseboards stick out from the wall. The radiator covers are an inch taller than the wooded baseboards, so there is a small space between the top of the cover and the wall.

I was thinking of spraying foam insulation into this space, then caulking the bottom of the radiator cover that sits on the floor. This would "entomb" the draft and at least keep it contained behind the cover. Is this a reasonble solution, or are there other ideas to stop the draft coming into the house?



Please search InspectApedia for the article title

Steam or Hot Water Boiler, Heating Pipe or Radiator Noises: Diagnosis, Causes, Cures

to see how we diagnose and fix noisy pipes, baseboards, & radiators.

If you are convinced that the problem is where piping penetrates floorboards, you'll want to install slip joint seals there - neoprene or other plastic fittings that close the openings against drafts but allow the pipes to move without creaking.

I think before entombing or gluing or spraying - all possibilities - I would use a mechanic's stethoscope with some care to pinpoint the actual noise source.

Keep me posted.

Question: heating pipe leaks can cause mold trouble and odors

(Feb 10, 2014) cynthia said:

4 storey apt building.I live on top floor, corner of building. Baseboard water/copper heating on complete perimeter of suite. Two years ago a vent stack in the wall leaked caused mold. Fixed. Now a chronic bad smell - almost wafting in at certain times of night and day.

Always under the windows. Building built 1970's.....can't identify the smell but it is awful,and sometimes weather dependent, could it be the vent stack that sits in the wall. It does not penetrate the flat roof.



if there was even a single substantial leak into a wall cavity one would expect a mold problem unless proper work was done promptly - in 24-48 hours. Now, two years later, if you smell mold, there is mold - either because the initial cleanup was incomplete or because there's been another leak.

The fact that you think the odor emanates from under windows may point to leaks at the window exterior flashing, trim, or even sills.

Search InspectApedia for "leaks at windows" to see details.

Question: how to test for chemicals contaminating the baseboard in my home

(Mar 27, 2014) Lina said:

Hello, how to inspect or test if there is chemicals on the baseboard heat fins in my home?
Everytime I turn it on, the baseboard heat gives me headaches, pins and needles in my body and body aches.
I appreciate the help!


Lina you could use a sterile swab kit and services of a forensic testing laboratory, but I recommend checking first with your doctor.

Question: I would like to remove the endcap on the baseboard heater

(May 14, 2014) I would like to remove the endcap on the baseboard heater said:

HI. My 81 year old mom has a modest size bathroom and I am trying to free up as much space in there for her bathroom equipment needs. One thing that could help give a few inches in the door opening a little wider is if I could remove the left endcap on the baseboard heater which prevents the door from opening all the way.

I might gain 1-2" on the door swing. For some reason (not sure why) there is no endcap on the other (right end). This is a nonelectric baseboard installed in 1970, i dont know the brand name, it has a dark brown aluminum cover. It does a good job of heating the bathroom, but takes up space,.

Is there a downside to removing it? Thanks very much for your assistance! Sandy



If you remove all bathroom heat the risk is frozen pipes.

YOu could replace it with a kick-space heater located in the bottom of a vanity cabinet.

Question: Is it normal to hear a low but still audible sound of flowing water coming from the copper

5/25/14 Rob said:

I live in a building condo that uses hot water baseboard heating. Is it normal to hear a low but still audible sound of flowing water coming from the copper which carry the hot water through the system?

Is it reasonable to expect that such a heating system should be completely silent when not in use/off?

Side-note: I do not have direct access to the main water pump or boiler.

flag like



"Normal" is not quite what I'd offer. It's common to hear some sound in hot water heating piping and most often that is an indicator that there is air in the system. If that's the case and the air quantity becomes significant, the system can become airbound and you'll simply have no heat.

When the system is not in use, it should not be making noise. If yours is making noise I wonder if hot water is circulating by convection, perhaps because a check valve is not working or was omitted.

(May 26, 2014) rob said:

I suspect one reason might be a faulty actuator valve assembly. Is it possible that the valve in that assembly could be faulty and not closing properly, resulting in a flowing water noise?
I have been experiencing the noise 24/7.

It also loudly bangs, once at a time, when the thermostat opens the valve (or when I set it to 'open'), but this occurs intermittently and usually only after it has been left open after some time.

When the valve is closed after it has been left open (during the night for instance), I hear an immediate steady build up in the pipes and then a loud, single bang.

What could that indicate?

For the record I've only done a hours worth of internet research.


Rob if you are referring to a zone valve that's not closing when it should, that would allow heat to circulate when you don't want it.

But still unless there is air in the piping the water circulating noise is usually close to zero.

The loud banging sounds like a water hammer problem occurring in the heating system. Usually that's associated with higher velocity water circulation. Certainly it's abnormal.

You can easily determine if a zone valve or check valve is open when it should be shut: with the affected zone NOT calling for heat, after a hour or so since last call for heat, feel the heating pipes on either size of the valve. If the piping is hot on both inlet and outlet sides of the valve then it's most likely "open".

Question: how to clean hot water heating baseboard finned tubing

(July 15, 2014) Karen said:

I moved into an apartment with baseboard heating registers similar to ones on the website. I need to clean them. Then are really dirty. I would like to disassemble the cover and clean the fins. Then reassemble the covers properly. Please send me detailed information on how to complete this task


Karen most hot water heating baseboards are comprised of

The steel front face is basically a flattened "U" shaped component whose top edge hangs over a vertical support inside the baseboard assembly and whose bottom edge "clips" onto the bottom edge of the same support.

Carfully pulling the bottom edge down and outwards will remove the front face to expose the finned copper tubing.

TAKE CARE: not to damage the fins by aggressive cleaning or vacuuming. Use a soft brush not a hard crevice tool, or if you're using a crevice tool, hold it near but not scraping along the fins themselves or you'll damage them - reducing future heat output.

Remember to vacuum along the floor under the baseboard as well.

Question: ok to run heating return line over the heating baseboard finned tubing?

(July 17, 2014) Dan said:
Hello, is it ok to run a return under or over the finned tube in a baseboard system?



Yes, it's a common practice to double back the heating baseboard return lline over or even under the finned tubing when the building properties prevent a normal loop plumbing arrangement.

Watch out that your return line doesn't block air flow from entering at the under-side of the baseboard cover

(July 20, 2014) Dan said:
will this reduce efficiency?


Possibly if inflow is blocked, but in ithat ions where there is no choice the heat requirement dominates the decision. Add extra footage if you worry about insufficient btus

Question: bad nail polish smell from heating baseboards

(Oct 23, 2014) Robert said:

Hi, our house has steam heating system with old cast iron radiators on the first floor and baseboard radiators on the second floor. After the summer we turned on the heat and the baseboard radiators started to smell really bad.

It smells like nail polish or new oil paint burning out. I drained the old black water, but it did not help. Then I took down the baseboard radiator that was leaking and it was full of white water with pieces of rust and it was the source of the smell. For some reason however, the bad smell is still present when we heat up the house. Do you have any clue how we can get rid of it?



First check that there are no leaks at the baseboards; as the same water usually remains inside a hot water heating system it can be a bit ugly and smelly.

Second check that the odor may have come from automagic air bleed valves on the baseboards - if so those vents are doing their job properly and the smell should be a one time event.

If the smells persist I suspect something was spilled onto the heaters.

Question: pinging sound from heating baseboards

(Oct 27, 2014) Aaron said:
Hi our baseboard is making a "pinging" noise when the system kicks on. Is this the fins? Or the pipe shifting positions as it fills with water?


This is typically caused by thermal movement of the baseboard covers and on occasion the piping where it passes over supports or through wall, floor or ceiling penetrations. You may hear it again as the system cools down.

Changing to noisless pipe supports and providing insulated clearance at penetrations can cut this noise down significantly.


Continue reading at AIR-BOUND HEATING SYSTEMS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see AIR BLEEDER VALVES for how to find and operate those cute little controls on baseboards (or radiators)

Or see DIAGNOSE & FIX HEATING PROBLEMS-BOILER if the boiler is just not working like it should

Or see these

Baseboard heat repair articles

Suggested citation for this web page

BASEBOARD HEAT REPAIR FAQs2 at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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