When was the last time you looked underneath your refrigerator? If the answer is “never,” you are not alone. I cleaned my fridge shelves every month for years without ever realizing the real problem was hiding at the very bottom.

There are two spots back there quietly making your fridge work harder and smell worse.

The drip tray under the fridge

Most refrigerators have a removable drip tray at the bottom front, behind a small panel. It catches condensation and spills, and over time it turns into a shallow pool of murky water, old food bits, and sometimes mold.

• Pop off the lower front panel
• Slide out the tray
• Wash it with hot water and dish soap
• Wipe the area behind it while you are there

That faint musty smell you sometimes catch near the kitchen floor? Probably the tray. Mine had a mystery smell for weeks before I found it.

The condenser coils on the back

The coils on the back or bottom of the fridge release heat. When they get caked in dust and pet hair, the fridge has to work harder to stay cold, which uses more power and shortens the life of the compressor.

• Unplug the fridge first
• Vacuum the coils with a brush attachment
• Do it once or twice a year

If you have pets, do it more often. A fridge full of cat hair on the coils runs noticeably hotter and costs more to run than one that can breathe.