Preventing Black Marks on the Walls from Your Baseboard Heaters

BaseboardHeaterGhostingECI Comfort recently received a call from a long-time Levittown customer in North Park that was concerned about black marks on the walls above his baseboard heaters while spring cleaning. This is referred to as ghosting or thermal tracking, which is a relatively common phenomenon that plagues both old and new construction. Here’s a look into the causes and some things you can do to prevent it.

The dirty streaks that can appear above your baseboard are mostly created by dirt, dust or carbon soot from a number of sources like fireplaces, cigarette smoke, pets, cooking byproducts, etc. that are spread by the natural convection created by the heating cycle. If the warm, dirty air from the baseboard heater comes in contact with a cool wall or one with a higher moisture concentration the dusty particles are deposited.

Unfortunately, many of the homes in Levittown needed to replace their radiant floor heating with baseboard heat. And, if dark marks on the walls is an issue in your home here is how you can keep your baseboards clean and stop them from spreading dust and dirt around:


1. Turn off the power to your heater and remove its cover once you’re sure the heating element has cooled. Some covers lift right off, but others may require loosening a few screws or caps.


2. Remove any large pieces of debris from in between the aluminum heating fins that may be too big or stuck to vacuum up.


3. Gently vacuum in the inside of the heater using a soft brush attachment, being careful not to damage or bend any of the heater fins. If there is any additional debris that the vacuum cannot reach simply use a soft paintbrush to remove it.


4. If you have any excess dust on the surface of the fins use a soft cloth to remove it and straighten any fins that were bent in the previous step with a pair of needle-nose pliers.

At ECI Comfort Paul Giorgi is our BPI certified building analyst and he reminded me that this is also an air sealing and insulating opportunity that can make your home more efficient and save you money in the long run.

In the home performance business ghosting can also be a tell tale sign that the walls are significantly colder than the rest of the house. On exterior wall assemblies, lack of proper air sealing and insulation is the main culprit. On interior wall assemblies those open to attic spaces can have cold air currents traveling through these assemblies. This is called convective looping and can also contribute to this circumstance. Proper air sealing in the attic is the way best to mitigate this problem.


An electric baseboard heater in Colbalt Ridge

So, not only are these marks unsightly, but they are a symptom that your house is not performing as well as it should be. It is very likely that the problems that cause these thermal streaks are also contributing to higher heating and cooling costs as well and might be contributing to comfort issue’s in the home.

With a little elbow grease and proper insulation you can prevent these unattractive marks from your walls or floors and make your home more efficient in the process. You may also want to consider arranging the furniture in your room so that dirt and dust is not directed toward your heater.


This blog was supplied by Bill Eberhardt at ECI Comfort in Bensalem. ECI Comfort is our HVAC expert and you can learn more about them or ask them your question HERE.

One thought on “Preventing Black Marks on the Walls from Your Baseboard Heaters

  1. We have 50 yrs of this ghosting above the baseboard heat on original Knotty Pine Paneling. I don’t think it had any sealer applied to it when it was installed, it’s very porous. Cant you sugest a safe cleaning product to use on the wood to clean it without harming the wood. In the rest of the room the wood is still beautiful so I just want it to match as close as we can. Thank You

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