DEAR BARRY: I recently hired a contractor to clean and service my heating and air conditioning system. As he was doing this, two concerns arose: asbestos insulation on the air ducts and dust buildup inside the ducts.
When I asked about cleaning the ducts, he said that they cannot be adequately cleaned and that companies claiming to clean air ducts are just ripping off their customers. He recommended installing new ducts, rather than cleaning the old ones, but this would be very costly. Then, as a side note, he mentioned that my ducts are insulated with asbestos — and this has me worried.
The insulation that is on the ducts is metallic in appearance, and I always heard that asbestos is white. What should I do about the asbestos (if that’s what it is) and with the dirty ducts? –Heather
DEAR HEATHER: Homes built before 1974 often have asbestos insulation on the air ducts. This type of asbestos appears in two common forms: either as gray-colored cardboard, or as foil-wrapped gray cardboard. The foil-covered type is apparently what you have on your ducts. Fortunately, there is no need to panic about this type of asbestos because the material is on the outside surfaces of the ducts; not in contact with the air that you breathe in your home.
Your contractor’s unfavorable view of duct cleaning, however, is unfounded. Old ducts are typically made of sheet metal, and these are the easiest of all to clean. Therefore, professional cleaning is recommended. And to increase energy efficiency, you can have fiberglass insulation installed over the asbestos.
DEAR BARRY: My water heater is leaking at the fitting where the relief valve is screwed into the tank. The valve itself seems to be OK, but water trickles along the outside of the valve and the adjoining pipe. When I called the manufacturer, they said the valve needs to be replaced. Does that suggestion make sense to you? –Tom
DEAR TOM: Actually, that suggestion does not make sense. If the valve itself were leaking, water would drip from the end of the discharge pipe. If the leak occurs where the valve is screwed into the tank, there are two possible problems: Either the tank or one of the supply connections has a leak that is emerging at the relief valve, or the valve fitting was not adequately sealed when it was screwed into the tank.
The first thing to do is check the supply fittings at the top of the tank. If no leaking is observed, you should reinstall the relief valve to make sure the pipe threads are adequately sealed. Before you do this, turn off the water supply and partially drain the water in the tank. Unscrew the relief valve from the tank, apply pipe joint compound or Teflon tape to the threaded fitting, and screw the valve tightly into the opening. Once this is done, reopen the supply valve to see if the leaking resumes. If it does, you probably need a new water heater.
To write to Barry Stone, please visit him on the Web at www.housedetective.com.
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