The thermostat is one of those things that you don’t pay too much attention to until it breaks. Usually, thermostats do their job quietly, in the background, without requiring much outside interference, but when it stops working, everybody in the house notices. When the temperature inside is suddenly freezing cold or burning hot, most homeowners will do just about anything to fix it and restore a comfortable environment.

Some thermostat devices are older and more basic than modern examples, operating on very simple mechanical principles. This system is sometimes joined with a mercury switch, which is a tube filled with mercury that also tilts as the coil expands or contracts, causing the mercury to move from one side to the other and thus opening or closing the points of contact.

Modern types of thermostats are electronic and function like a small computer. Often, these are programmable, allowing you versatile flexibility in how you set temperature controls, timers and preferences. Unlike electro mechanical thermostats, which require manual adjustments, electronic versions allow you to set the temperature for a different setting when you sleep, wake up, return home and even for different days, such as on weekdays and weekends. This is a much more convenient setup than the simpler models, but it also means that there are more pieces that can break and maintenance work is more difficult and expensive. There are often inexpensive electronic models, making it often more feasible to simply replace your unit than try to fix it.

Being caught in the cold winter months with a poor furnace is a situation that nobody wants to be in, but there are things you can do to remedy the problem on your own. If you notice an issue, check the power source, looking for things such as blown fuses, tripped breakers and dead batteries. Check for dirt, dust, spider webs and nicotine buildup. These can coat the inside of the thermostat and cause the mechanical and electrical components to malfunction. To clean, use a soft brush, like a clean paintbrush, to gently brush the interior components. Compressed air is also useful in cleaning out the thermostat. Also check for loose screws and corroded or loose wires inside the thermostat.

Another function to check before calling a professional is whether the thermostat keeps the room at the correct temperature or not. To do this, tape a small thermometer on the wall next to the thermostat, being sure to place a paper towel behind the thermometer so that it won’t be affected by heat or cold transfer from the wall. Wait for at least 15 minutes to ensure that temperature is stabilized and giving a correct reading, then compare it to the reading on your thermostat. If the numbers are more than a degree apart, the thermostat is likely not giving an accurate reading. This is a very important factor to know when you speak with the repairman about the problem.

Remember to make sure the inside of the thermostat is clean. Check if the thermostat box is level, since being off-center can alter the accuracy of the internal component. Also check your box’s location, since placement in direct sunlight or in front of drafty windows and doors can greatly affect correct temperature regulation.

Having a thermostat that functions correctly is vital to keeping your home comfortable and livable during any weather.