Furnace RepairMystery Stains On Ceiling And Walls? It Could Be Your Furnace

Track down ghosting stains to find and eliminate the source.

It seems to appear from nowhere – mystery spots of grayish black deposits on your ceilings and walls. Where do these mystery stains come from? A number of sources can contribute to such stains and one of them could be a poorly maintained furnace. Follow this advice for tracking down the source of ghosting stains like these in your home.

Ghosting and Particle Buildup

Ghosting happens slowly over time. Tiny particles accumulate in an area and eventually create a stain. In some cases, you may need lab analysis to figure out what’s going on, but it’s expensive. In most cases, the source of ghosting is carbon produced by combustion. It can also come from certain types of wax, grease and organic particles like dirt.

How Did the Stain Get There?

Ghosting happens for complex and varied reasons. It can occur when cooler areas on your walls and ceiling condense to form moisture. As air travels through the home, particles stick to the moisture, creating a ghosting stain over time. It can occur when air travels through small cracks, forcing particles to impact on surrounding surfaces. Gravity can pull particles down onto surfaces and static electricity can attract particles with an opposite charge to objects.

Questions to Ask

To accumulate and cause black or gray stains, the particles must be present in the first place. Finding out what’s putting the particles in the air is the first step in diagnosing the problem. Ask yourself the following questions to figure out where those stains are coming from:

  • Does Your Home Have Negative Pressure? – Negative pressure is most noticeable at large openings like a fireplace or cooktop exhaust fan. A tight home can be too tight, ducts may be leaky or wind patterns can cause negative pressure on one side of the house. When this happens, the dirt, pollen and vehicle exhaust particles are sucked into your home, depositing where they find opportunity. Call for an energy audit to find out what’s causing the negative pressure.
  • Did you try a new type of candle or begin burning candles on a regular basis recently? – Candles containing paraffin can leave deposits on the ceiling as the particles burn and float upward with the rising heat from the flame. This is also true of candles using scented oils, which create a great deal of soot when they burn.
  • Do you use a gas log? – Gas log fireplaces can create soot if not maintained properly. The logs can impinge the pilot light, creating soot that travels through the home and deposits on surfaces. Have your gas log serviced to check for this problem.
  • When was your heating system last serviced? – A poorly maintained furnace can burn inefficiently creating excess carbon. These particles eventually travel throughout the home, depositing where there is sufficient static electricity or humidity to make them stick. If it’s been more than a year since your last service visit, it’s time to make that call.

Call MM Comfort Systems to Diagnose Your Ghosting Problem

MM Comfort Systems helps residents in Bellevue and Redmond keeping their heating and cooling systems running right. Call us at  425.533.9058  or use our online contact form to set up a home energy audit that will help identify the source of your ghosting problem.


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