Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

smell coming from radiators

Rose Member Posts: 1
I am writing to ask for help in diagnosing a problem we are having with the radiators in our home. Our house was built in 1925 and we have gas heat with the orignial radiators in each room. Our problem is that there is an odd, unpleasant smell eminating from many of the radiators in the house. In particular, the smell is the worst from the radiator in our kitchen (which is toward the back of the house) and the radiator in our bedroom (which is upstairs over the kitchen). The odd thing is that the smell is less detectable during the colder months when the radiators are in regular use. The smell comes back when the weather is warm and is at its worst when the weather is humid outside, which of course is when the radiators are not in use. We thought perhaps that something was coming from the sitting water in the radiators, or from the actual surface of the radiator itself, rather than from the water inside. Its hard to describe the smell, its almost a bit of a dirty diaper, musty smell. Has anyone ever heard of this?

We have to figure out where the smell is coming from, including having two different heating repair companies come to our home and inspect our boiler and look at a few individual radiators. They did not find any leaks with the system and bled the radiators and the water was clear in one radiator and black in the other radiator but became clear when they bled it some more.

We then began to wonder if there was something on the surface of the radiator causing this smell (there are many layers of paint on them from the years, and we thought perhaps the paint didn't mix well with the radiator--is that possible as a longterm problem?), so we had someone come and clean the oustide of a few radiators, which seems to have helped a bit but did not solve the problem. Now that the weather is getting warmer, the smell is getting stronger and is very unpleasant. When we put our face up close to the radiators, we can actually smell this annoying odor. We are struggling to fix this since no one whose come to our house has been able to figure out why the smell is occurring.

We have a toddler in our home and want to make sure this isn't unhealthy for her. Thank you so much for any information you may have that can point us in the right direction to getting this problem fixed.



  • Firedragon_4
    Firedragon_4 Member Posts: 1,436
    I'd have the radiators sandblasted and repainted

    to match the color of the rooms in just a good water-based paint.
  • JimGPE_3
    JimGPE_3 Member Posts: 240
    I'm bettin' it ain't the radiators....

    Did you check for mold in the wall behind the radiator? The musty, dirty diaper smell sounds like mold.

    It almost certainly is not anything inside the radiator, as it is a sealed unit. If the vent leaked, you could smell some of the internal odor of the radiator, but that would be most noticeable when the boiler is fired up in the dead of winter, which is not your case.

    Perhaps the heat keeps the mold in check, then when the temperature changes, it reactivates.

    Check out the walls BEHIND the radiators - that's my best guess.
  • JimGPE_3
    JimGPE_3 Member Posts: 240
    Water based?

    You guys would know better than I, but if the rads are cast iron, won't they rust from the water and the rust bleed through? Just a thought.
  • Ron Huber
    Ron Huber Member Posts: 121

    It sounds like mold, and use a high quality oil based paint if you decide to paint them, water based will blister.
  • jim lockard
    jim lockard Member Posts: 1,059
    Have -U-

    Looked at the outside of your house behind the Rad? Maybe some signs of water damage I would check from roof to foundation --you never know. I had water coming in thru a poorly installed molding above the window. J.Lockard
This discussion has been closed.