Listen to your aging oil tank before deciding whether to replace it

Q. My oil tank in the basement is all of 43 years old, but with no signs of a leak. Should I replace it?
T.S., Belmont

A. I can't say if it ain't broke don't fix it, because at 43 years the tank may be entering a critical stage in its life. If it leaks it can damage the basement floor, and if it gets under the floor it is very critical, and difficult and expensive to remove. And you are responsible if that oil contaminates the world. You could try this test, or have your oil dealer do it. Tap the bottom of the tank lightly with a hammer; if it goes ''clump" and not ''ding," it may be decaying and ready to leak. A sound tank will ring a bit, even full of oil; a rotting one will have little or no ring to it.

So, if you are really concerned, replace it now. My own tank is 45 years old, and while it it is not leaking and rings a bit when I tap it, you have got me thinking.

Q. I heard you should not burn painted wood in the fireplace. Is that so? How about stained wood?
CONCERNED

A. Yes, it is so, because of the danger of the paint containing lead. And fireplaces are so inefficient that they can't help releasing some smoke and fumes into the house. Stained wood? If the stain is solid-color latex, the stain is very close to paint anyway and should not be burned, even though it probably does not contain lead. If the stain is semitransparent, you can burn limited amounts of it. The longer the stain has been on wood outdoors, the less stain will be in the wood.

Now here is the caveat: You should not burn painted or stained wood as the main wood in a fireplace because it is soft, and will burn too fast and too hot for good heating purposes. Hardwood should be used as the main fuel. Stained wood (semitransparent and solid-color latex) can be used as kindling in limited amounts, just enough to get the fire going. Painted wood should not be used under any circumstances because it may contain lead.

If any of the wood is pressure-treated, the taboo is total. Do not burn it.

Q. My stucco house is 100 years old, and some cracks that seemed unfixable were repaired by a stucco man. More recently a large chunk fell off, and it was repaired nicely. My only problem is that there is an open space between the outside window sills and the stucco. Should I fill it?
PRETTY COOL

A. Yes, by all means. Fill it with caulking compound. The gap is unlikely to leak water into the wall, but it sure as heck is losing heat from inside. There are sheathing boards under the stucco, and they may be tight against the sill. But since you don't know that, and there is no easy way to find out, caulking is a good idea. If the gap is too big for ordinary caulking, stick in a length of rope caulk, which is a flexible material that fills larger gaps. It's a contemporary form of oakum.

Q. When my house was flooded, the power went off. The lights were turned off before the power failed. When the power came on, those turned-off lights went on. The electrician said this is normal. Friends said this should not happen. Also, since the power failure and restoration, the lights keep dimming. What can I do?
CECILE KRAMER, Newton

A. There are strange things happening with your circuits. For starters, get another electrician; I can't believe that what happened is normal. Also, call the town building inspector. If the town has an electricity inspector, call him, too.

Does anyone ''out there" know what is happening? Cecile and the Handyman would dearly like to know.

Q. I have an unglazed clay pot stuck inside a porcelain pot. I like both pots, but I can sacrifice the unglazed one if necessary. How can I get them loose?
B.S., Wellesley

A. You may not have to sacrifice anything. Put the outer pot (the porcelain one) in a big bowl of very, very hot water, and fill the inner pot (the unglazed one) with ice cubes. Add water to the ice cubes, which will make the porcelain pot cooler. Wait 10 minutes or so and see if they will come apart. This cold-hot treatment will cause the hot pot to expand and the cold one to contract, making it easier to pull them apart.

Q. I heat and cool my two-bedroom townhouse with a heat pump. It works well, but I notice a lot more dirt than before I used the heat pump. I see what I think is soot on the rugs upstairs, and think it is related to the heat ducts. Should I clean the ducts?

One more little thing: In corners where two walls meet and at the ceiling where the walls meet, the ceiling also shows dirt. How can I prevent that? A half-bath with no windows and no ducts is perfect.
ARTHUR CREAGER,East Boston

A. My first question is: Do you burn aromatic candles? If so, stop. Aromatic candles are notorious soot makers, and stopping their use will make a big difference. You can also have the ducts cleaned.

The areas near the ceiling and in corners of the wall are looking dirty because they are cooler than the rest of the wall and ceiling, and water vapor condenses on the cool areas and dirt sticks to the damp surface. You probably cannot even feel that it is damp, but it is. And, instead of dirt, mold might be growing. To find out, paint a small area with household bleach. If it turns light quickly, it is mold; if it does not, it is dirt. Treat mold with a 1-to-3 bleach-water solution, and dirt the usual way. Wear skin and eye protection when working with bleach.

Those various cool spots are cool because of inadequate insulation or no insulation at all. It is not easily fixed.

Q. My two bathroom vents are vented into the attic, discharging near the ridge vent. Is this reasonable to release all that warm, moist bathroom air to the outdoors?
STUART MONROE, Hudson

A. No, not by a long shot. The idea, of course, was to get the ends of the vents reasonably close to the ridge vent so the vent would sort of suck out the moist air. Baloney. That is a lazy man's way. The only right way is to install a roof vent and put the two bath vents into it, with all connections tight enough to prevent any bath air getting into the attic. If any of that moist air does get into the attic, it will condense into water and you are bound to get mold growing.

Globe Handyman on Call Peter Hotton is available 1-6 p.m. Tuesdays to answer questions on house repair. Call 617-929-2930. Hotton also chats online about house matters 2-3 p.m. Thursdays. To participate, go to Boston.com. Hotton's e-mail is photton@globe.com.