Snug-fitting, well-maintained storm windows and doors can do much to reduce heating bills. The space between the storm and prime windows, or between the storm and house doors, creates an insulating pocket of air that reduces heat loss to the outside.

Here are some tips for keeping your storm doors and windows in top condition:- If your aluminum storm windows and doors are unpainted, brush the frames with fine steel wool to remove oxidation once a year. Then apply a good automobile paste wax.

- Remove wood-sash storm windows periodically and repaint them. This is important not just for looks but to prevent absorption of moisture that may cause swelling, warping and rotting.

- While a wood-sash storm window is out, before repainting, inspect it for damage.

- Reglue loose joints and reinforce them with corner plates available at your local hardware store.

- Replace crumbling or missing putty.

- Repair bent hardware. Inspect the hangers for loose or missing screws and damage to the bracket on the house or the hook on the storm sash.

- Check the interior fasteners to be certain they are all functioning properly.

- To paint all sides of the storm sash in one operation, install storm window hangers in a ceiling joist in your cellar or garage, and suspend the storm sash from it.

- After the paint dries, put adhesive-backed foam weather-stripping on the inner edge of the sash to make it more air-tight.

- Keep the drain holes in the bottom of your aluminum storm windows clear to prevent condensation from rotting the sills. If your windows don't have these holes, drill three 1/8-inch holes.

- When a storm door begins to sag, use a wire cable and a turnbuckle to give it a lift. (Both are available at hardware stores.)

Here's how:

1. Install sheet metal screws on the top inside corner of the hinge side and on the bottom corner diagonally opposite it on the latch side. Use wood screws on wood storm windows.

2. Measure out enough wire cable so that it can be securely fastened diagonally to the two screws. Then secure the wire to the screws, pulling it tight but not taut.

3. Cut the wire at its midpoint and fasten the cut ends to the turnbuckle.

4. Tighten the turnbuckle until the wire is taut and the door sag is eliminated.

- If your aluminum storm door won't close because it's hitting the frame, try to realign the metal frame by tightening the screws that hold it to the jamb on the hinge side.

- If your storm door won't close and it's not hitting the frame, the problem may be with the door's tubular pneumatic closer.

Most pneumatic door closers can be adjusted by turning the slotted screw in the center of the end cap. Turning the screw counterclockwise makes a door close faster. Turning it clockwise makes a door close more slowly.

- When taking down screens and installing storm windows, write a number on a hidden spot on each window frame, as well as on its matching screen and storm sash. Put hardware removed for storage in a bag marked with its window number.