Question: I recently removed wallpaper from plaster and lath walls, and although I thought I removed all the glue and residue and sanded prior to applying an oil-based primer, I am still experiencing some sort of "flaking." It does not appear to be the paint, but the paper adhesive or glue.

Any tips on how to remedy this prior to applying a latex top coat?

Answer: The problem, judging from my own experience and the opinions of a couple of experts, is that you didn't remove all the adhesive from the walls before you primed it. KILZ, which is what you used, was the correct primer. But before you applied it, the walls should have been thoroughly cleaned of glue residue. The fact that the walls are flaking and probably have spidery cracks in the newly painted area means that you didn't.

I hate to suggest this, but you may have to sand the surface again, then apply a glue remover and clean and rinse several times before reapplying the KILZ. That may work.

If anyone can offer another suggestion, please send it along to me, and I'll include it in a future column.

Q: With the current oil-price crisis, maybe you can help me. We have a 30-year-old ranch house with the original oil heater and a buried 500-gallon tank. We also have a pretty large above-ground propane tank for the pool heater and barbecue.

Can you suggest where to get help in deciding whether replacing the current oil heater with a propane-fueled heater would be more economical? We don't have a gas line in the street.

A: First off, your 30-year-old heater is probably very inefficient, and since a growing number of experts are suggesting that the current crisis is just the beginning, you should start looking for as efficient an oil burner as you can find. But simply replacing a heater, no matter how old, is just one step in a whole-house approach to energy conservation and comfortable living. I'd also have an energy audit performed, although there don't seem to be enough people with this expertise around yet and you'll probably have to search for one.

The buried tank is an environmental accident waiting to happen. Whether you convert to propane or not, you'll need to have the tank inspected. If it leaks into the soil and then the groundwater, cleanup becomes incredibly costly. Homeowner's insurance companies have been asking questions about buried tanks at renewal time - probably another thing for which to eliminate coverage.

With regard to propane as an alternative: Its price rises and falls just as fuel oil's does, so no one can guarantee that one will always be cheaper than the other. Conversion costs should play a major role in any decision you make.

Q: I was wondering if you know what may be causing our fireplace to emit a heavy ash odor during humid weather, mostly when it's hot, but sometimes when it's raining and mild. We last had the fireplace cleaned two years ago, but the odor came back even before we burned a fire.

I contacted the company that did the job, and the man suggested installing a chimney cap, which we did, but that hasn't helped.

A: Masonry will absorb moisture and retain odors for a long period. Chimney odors are always present, but the natural draft during cold weather carries the odor up the chimney, so you don't notice it. The natural draft in warmer weather is reversed, so the air flow is into the house instead of out the top of the chimney. Odors also are usually greater when it is raining or very humid outdoors.

Glazed creosote produces the worst odor and is tough to remove, but it must be. A chimney cap reduces moisture intrusion but not humidity. You can use a special deodorant designed for chimney odors; check the Internet for sources. You can even open a window in the room a crack to reverse the air flow.