Heating Radiator, Baseboard & Convector FAQs

Diagnostic questions help repair cold, leaky, noisy radiators & baseboards

Radiator or Convector Asbestos or Lead?

Our radiators are recessed into wall cavity - asbestos?

I recently purchased a house built in 1960. It is a brick ranch. I have recessed radiators. I've never seen radiators like this. They are literally in the wall and do not look like your standard radiator.

While trying to clean behind them, I noticed some type of foil which is stapled to some sort of insulating board that looks like card board on the bottom.

Could this brown fiberboard contain asbestos? I've been worried sick over this. Any help or comment is appreciated. - A.S. 8/4/2014

Reply:

The foil faced board behind the recessed radiator was added to help direct heat out into the room and is in a position where even if the board contained asbestos (which I doubt based on the ones I've seen) it is in a position where mechanical disturbance is very unlikely - making the risk very low.

If you want to send us some sharp photos of the whole radiator in-wall installation and closeups of the reflective board you have seen I will be glad to comment further.

A recessed heating convector (newer than your radiator most likely) is shown in the article above. And comments about improving the heat output of recessed radiators are

at RADIATOR BASEBOARD or CONVECTOR COVERS

Worry about the safety of chipped paint on an oil-filled electric radiator?

Hi, I have a question about my oil filled radiator heater, this is the closest sub-article I could find to post a question...please direct me to the proper page if you don't cover this here.

I have a Black and Decker heater (portable sealed oil radiator), I haven't used it in ten years.

There are little chips in the outer enamel of the heater,along the outter edges along the top, revealing little specks of the metal radiator underneath

. There are no actual holes in it, but I wondered how important that paint is on the outside and if it's really dangerous to use the heater if there are hole's in the enamel.

like would it create a pressure difference that could cause it to burst open or something.

I guess those spots would be could be much hotter....I'm sure if I should use it or not.

Thanks for any feedback. rob. (Nov 26, 2014) Robert

Reply:

Robert it doesn't sound dangers from your description; if you see heavy rust or perforation and leaks the radiator is shot and should be discarded. A minor paint chip won't affect its operation; If the radiator looks beaten-up I'd worry about the condition and safety of its wiring.

Radiator Leaks or Cracks

What caused a cracked blown radiator in our house?

Our old convector kitchen radiator 'blew' with water spewing from two areas. Had to be disconnected. It's been bitter cold, but heat was on and efficient, !2 hours later the living room radiator blew, same thing as kitchen. Heat was on, but window above radiator was open.

Did the cold air seeping in get drawn down into the radiator and crack it?

Kitchen radiator is positioned under window and next to a door, where door was left open and drafts came in while radiator was blasting heat and temps outside single digits.

We are ordering new radiators, but wondering if we did something wrong to end life of these two, since we have 5 more working and want to avoid them blowing. (Feb 2, 2014) Lynda

Reply: frozen hot water heating radiators?

I can't tell if you have steam or hot water radiators but I suspect they were left shut off and froze leading to cracks. A cold air leak could be at fault.

Lydia,

A radiator that "blew" and spewed water is indeed a worry - are these cast-iron radiators? Was the heating system pressure at normal levels (say under 30 psi for hot water heat and und er .5 psi for low pressure steam heat?)

Indeed if heat has been left off it is possible for a radiator to freeze and as ice expands, to crack - a problem that won't show up until things thaw out.

I would look for drafts, insulation voids, or a period when the home was left without heat. I'd also double check that the radiators were not turned off or air-bound.

Normally an air-bound radiator is also not going to get hot and if it were really full of air it wouldn't freeze. But if that radiator also contained some water it could freeze as well.

How do I fix a leaky steam radiator vent?

Our steam heat system has a radiator that constantly spews mist when the furnace is running. Is there a part we can get to stop this annoying problem? Thank you very much! (Jan 25, 2013) Doug and Nancy Smith, Pinehurst,

Reply:

See the detailed repair steps I've written for you

at STEAM RADIATOR VENT CLEAN & TEST

How to replace a cracked threaded nut on a steam radiator

I have an old trane steam baseboard convector radiator system in my office.

The threaded nut cracked that seals it to the radiator. I am looking for a source just for the nut. It is a 3/4 inch nut and it is on a 1/2 inch pipe. It connects from the steam trap to the radiator.

Reply:

Daniel, for old radiator parts you might still find an exact match or an equivalent if you can take the old cracked connecting nut to a large plumbing supplier - the pipe threads should be standard; Another source is folks who sell renovation hardware and heating radiators.

As a last resort, I've taken such parts to a machinist who could MAKE me a duplicate.

You might pay more for the part but you're saving a much more costly replacement job. (July 22, 2011) Daniel

There's too much air in our radiators

I have a Radiant heating system in my house and it work great in all the rooms but one.

Of course it is my daughters room. I have to bleed the rad (a traditional wall-mounted heating convector unit) once or twice a week or it will not have much heat to it.

It always seems to have a bunch of air in the rad. The boiler is a newer boiler and is in the basement with the bedroom on the main floor.

Is there a valve that one can put into the rad that would allow the air to escape without me constantly having to bleed it? Any thoughts or help would be great. The valve on the floor is open fully, all other rads are working well. (Mar 29, 2012) Andrew Duncan

Reply: two solutions

I think you're describing hot water radiators, not RADIANT HEAT 

Try installing an automatic air vent on that radiator, like the ones we describe at AIR BLEED VALVE INSTALLATION 

As long as the radiator keeps getting hot with that vent you're probably OK, but if the air problem in your heating pipes gets worse,

see AIR-BOUND HEATING SYSTEMS - home

My baseboard heaters are cold, what do I do?

My baseboards are not emitting heat however i still have hot running water.

i changed the thermostat with no luck. how do i get the baseboards to start letting out heat again? (Oct 12, 2012) jim

Reply:

See the step by step diagosis and repair we give at

• COLD HEATING RADIATOR REPAIR (hot water / hydronic heat) - diagnose & repair
• STEAM HEAT RADIATOR REPAIR - diagnose & repair

Tips for cold radiator diagnosis and repair

I have oil heat and old vintage radiators. I turned on the heat yesterday and again today because yesterday the heat comes on but the radiators are not heating up.

They are still cold. I tried letting the air out of the radiators but the radiators still wont heat up. When I let the air out of the radiators, air and water comes out. How much water should come out?

Should I let all of the water out or just a little just to get the air out?

Please advise because my house is cold since my radiators wont heat up. (Oct 6, 2014) kimmi

Reply:

Kimmi

NO water should be coming out of the radiators - or that is, if you are bleeding out AIR, then STOP bleeding as soon as water starts squirting out of the air bleeder.

If no more air is coming out of your radiators (this is hot water heat not steam heat) then the radiators are not air-bound and the problem is elsewhere. Check that the boiler is coming on and that circulators (if any) are running and zone valves (if any) are opening. Feel pipes on the inlet and outlet side of a circulator or control to see if hot water is passing through (watch out for getting burned).

See the article series beginning at AIR BLEEDER VALVES

If bleeding air out of your old radiators doesn't get them hot we need to check that the circulator pump is running and that the system isn't air bound.

Details for those procedures are at these two pages

• COLD HEATING RADIATOR REPAIR (hot water / hydronic heat) - diagnose & repair

• AIR-BOUND HEATING SYSTEMS - home

I Bled the radiator but it's still cold

The hot water radiator stopped heating all of a sudden. I bled it, some air came out but not much.

I bled it 3 times, I let water out but radiator is still cold. The water that comes out is very hot but the radiator is very cold. What can I do? On 2020-01-05 by Rose

by (mod) - sounds like debris clogging

Rose

With so little information I can only make a vague guess. But it's possible that your radiator outlet is blocked or clogged with debris such as rust flakes.

If hot water is definitely entering the radiator but the rest of the radiator body stays cold the radiator is either airbound or its outlet is clogged.

Since you've bled the top of the radiator where are would escape and you're getting no more air, that suggests that the radiator may be clogged or blocked. It's time to get some help from a heating service technician.

by Rose

Thank you so much for your reply. Yea, will have my plumber in.

Radiators fluctuate between too cold and too hot in Public Housing

My friend lives in a public housing type situation. So any issues have maintenance guy come and fix or they call and you wait for weeks on end.

In the winter his place was freezing. The maintenance guy would come turn the thermostat up. Did that three times. Then came and replaced it.

I bought him a small room heater to assist until it's fixed. You know it's bad when your wearing winter coat in your room.

He's got radiators all through the place. The basement area where a lot of meters and heaters etc are down there locked up.

But anyway so towards the end of January they finally got professionals in a red truck work on the heat in the building which is 3 floors so other tenants there too with no heat. Older adults seniors I might add.

It took roughly 2 hours due to bleeding the lines the pipes leaked water but eventually they blasted heat.

Now the issue is having them turn it off. I'm writing this it's 82 degrees outside.

I don't know if the maintenance guy is just forgetful or they got a new guy because this guy came and did the same thing.

Turned down the heat on the thermostats from 80 to 70. Then did it again a week later to 60. Then he came and did something but it's blasting. My friend is very polite but it's so hot inside.

He's got an air conditioner on that's He's trying to cool down but obviously as you know heat works its just over compensating .

Even the not too cold days we had all the window open to push the heat out. Now the ac on we try to keep them closed but it's not much of a difference. I'm trying to find a cheap air conditioner to put in his room too.

He's called the maintenance people and his case worker to tell her the issue. They need to have the same guys who worked on the heat come back to turn it off. We are wasting electricity. His electric is included in his rent but I'm just surprised at how slow they are getting at this. I mean it's 3 floors .

We got 1 vet who just moved out 2 weeks ago over the issue. Do you have any recommendations?

The building itself is part of catholic charities and they have these case workers who call and deal with any issue that cannot be fixed with maintenance but it's freaking May. The heat being on in April was OK with the chilly days we had.

My building had the heat of April 15th so we had a few nights a weeks worth where I had to layer up so spending the night over here at his place was better. [I'm more a colder person normally] but even I am like barefoot which I hate - sorry to rant.

He called his manager and sternly told her what this building is like.

Hoping to have her call the right people.

Would it be OK to cover these radiators?

Or is there like a valve at the end of the pipe I can stop the water flow in each thingy? It's just crazy to me how slow they are working.

Luckily there's no babies and kids here but the older gentlemen down the hall who can't take this type of heat.

Is there any other steps or tips I can do to help him keep cool until they stop playing around and fix this?
Thanks for everything - On 2022-05-13 by Amber

Reply by InspectApedia Com Moderator - steps to reduce unwanted heat from radiators

@Amber,

I'm sorry for the aggravation and discomfort that your friend has been dealing with. It sounds like both of you have been doing what you can to address the issue.

Hopefully his case manager will be able to connect with his apartment manager/maintenance and get the heat problem fixed.

We know nothing about his actual radiator or building so can't give a definitive answer on how to address your questions.

There are ways to cover the radiator to block the heat but unless done correctly, it could actually increase rather than reduce the heat output. Please see more about radiator covers at:

HEATING RADIATORS & BASEBOARD COVERS

And again, not knowing anything about his system, a starting point for adjusting radiator control valves can be found at:

RADIATOR VALVES & VENT CONTROLS

This article also has links to several other related radiator control articles that may help.

Are there water temperature differences between convector heaters and baseboards?

Could you say that a convector radiator works the same as a baseboard radiator, you would'nt have to set different temperatures (Apr 15, 2014) wil

Reply:

Wil,

Yes. We do not set different water temperatures for convector heaters vs. their longer, lower sisters, baseboard heat. Using the same assumptions for building heat loss, the size, location, and number of convector heaters is chosen based on BTU requirements just as we do for baseboard heat.

If you look inside a convector heater you'll see a larger finned tubing segment, possibly with multiple bends of piping running through the tubing, and larger air intake and outlet openings than we see for the same *linear length* of heating baseboard. So we're getting more concentrated heat output from a convector in a shorter linear space than if we installed normal baseboard heaters.

It's worth noting however that there are also different models of baseboard heaters with varying levels of BTU output per linear foot.

After a lazy and annoying Poughkeepsie plumber installed 1/2" PEX tubing to supply hot water heat to our InspectApedia office rather than the 3/4" tubing that we had specified we visited J.D. Johnson, our local plumbing supplier for help from their resident heating engineer.

He explained that we had several choices of baseboard designs that, given the same incoming water temperature, could give different BTU heating output per linear foot. Choosing one of the higher output baseboard types could overcome our plumber's decision to install what was easy for him rather than good for us.

How do I fix noisy steam vents - rattles

We have steam radiators in my building and the landlord and I are trying to figure out the problem behind a rattling vent.

For about an hour every morning, a few of the radiators in our apartment hiss incredibly loudly non-stop; I'm pretty sure it's hot steam coming out. However, my radiator specifically may sometimes make a rattling noise.

If I cover the vent hole with a piece of cloth, the rattling stops, which makes me think it's a problem in the vent. We've replaced the vent once already now, and my landlord thinks that it might be a pressure issue.

However, he wants to avoid offsetting the balance of the entire apartment building and was wondering if putting a vent with a larger hole should fix the issue. I'm on the bottom floor so the vents have smaller holes than the ones above. (Nov 30, 2014) Erin

Reply:

Erin

Noisy steam vents are usually caused by worn vent parts or excessive condensate in the radiator.

If replacing the vent doesn't solve the problem your plumber will need to check for a blockage at the condensate return for the noisy rads.

See the articles beginning at RADIATOR STEAM VENTS - home

How to calculate how much antifreeze to add to a hot water heating system

We want to add proplyene glycol to our hot water heating system and are trying to calculate the amount of water in the system in order to calculate how much antifreeze is required.

How do you calculate the amount of fluid a radiator holds. We have 28 radiators of varying sizes! Thanks for your help (Oct 5, 2014) doug

Reply:

Doug,

In the More Reading links just above where you'll find a master ARTICLE INDEX for radiators please see the article titled

ANTIFREEZE for BOILERS for advice on how to add antifreeze - you don't really want to try calculating radiator volume.

I will include in that article a link to calculating radiator volumes - new material - later this morning.

Daniel