Can a faulty thermostat cause a high electric bill?
If so, then is it worth it to replace it with a new one, or should you just leave it as it is?
What are the symptoms that you have a faulty thermostat? And how does it affect your electric bill?
These questions and more, I will be answering in this short article, so, bear with me in order to know all the answers you need to know in order to keep your bills low and enjoy the money you will save in order to spend it somewhere else.
Can a Faulty Thermostat Cause High Electric Bill?
Yes, a thermostat can cause a high electric bill depending on what kind of fault it has and how it will perform under the faulty conditions.
This is because heating and cooling are amongst the biggest contributors to the energy bills in winter and summer.
And this applies whether a thermostat is used in connection with an air conditioner, or with a central heating system that uses a boiler to heat the place.
This is because thermostats were initially created to help regulate the work of the heating and cooling systems in order provide the most comfortable conditions with the lowest consumption of energy.
Even if the boiler in a central heating system runs on gas or diesel, you still need electricity to run the pumps that circulate the water through the system.
And a faulty thermostat will cause these pumps to work more often and for longer hours, which increases the electric bill, in addition to the heating bill.
How Much Can a Bill Increase Because of a Faulty Thermostat?
Depending on what happens to the thermostat as a result of the fault, the electric bill can increase.
It could cause a small increase on the energy used for the cooling or heating used, or it cause the energy used by that system to double.
In general, as per the latest EIA Residential Energy Consumption Survey (RECS), it was found that in the US, home air-conditioning costs averaged $265 in 2015, or 12% of the total home energy expenses.
But that’s the average.
In some hot-humid areas, the amount reached 27%.
And if we assume that the consumption of your AC accounts for 12% of your electric bill, and that you have the extreme condition where a faulty thermostat doubled the consumption of the AC system, then you get a total increase on your electric bill of around 12% because of the faulty thermostat.
And if you live in a hot-humid area where the air conditioning system accounts for 27% of your electric bill, then the extreme case of doubling the AC’s consumption could lead to an increase of 27% on the electric bill.
This is why, it is advised that you fix or replace a faulty thermostat as soon as possible in order to save on the energy bills.
5 Ways a Faulty Thermostat Affects Electric Bill
Not Reading Temperature Properly
The thermostat is supposed to turn on and off the heating and cooling systems based on preset temperature levels as leaving the system running on full load will not only over-heat or over-cool a certain space, but it will consume energy that could be saved and it will affect your energy bills.
And if a thermostat failed to read the temperature properly, then it might cause the heating or cooling system to run continuously even after the place has reached the desired temperature.
And that would cause the energy bill to increase significantly.
For example, if your AC was supposed to achieve the temperature of 78 F, and the place was cooled down to that level, but the thermostat kept reading the temperature as if it was 81 F, then it will force the AC to keep running on full load until the temperature is 75 F for example, which the thermostat might read as 78 and stops the AC.
These 3 extra degrees below the setting that the AC has worked to achieve, could cause an increase of 3% on the electric bill if the system happens to run for 8 hours a day.
And you can expect the bills to increase in the same way if the thermostat of a heating system is not reading the temperature properly.
Note: Sometimes the thermostat cannot read the temperature properly because it is place in a place that is subject to direct sunlight or another source of heat like behind a TV for example.
Check out our tips on how to run an AC economically to learn more about choosing the right place for a thermostat.
Reading Temperature, but Failing to Act
Sometimes the thermostat might be reading and recording the temperature properly, but it fails to turn on or off the heating or cooling system when the desired temperature is achieved.
This fault in a thermostat might cause a very high increase in electric bills.
For example, lets say that you have the AC set to cool down the place to 78 F.
Normally, if you leave the AC on for 8 hours in row, the thermostat will turn off the AC when that temperature is measured, and then, if the temperature goes up significantly, then it will turn it on again in order to bring the temperature down to 78 F again.
Turning on and off the AC doesn’t cost more. It works on saving money.
The cycle in which the AC operates is around 15 to 20 minutes before it goes off, and depending on how will the place is insulated, then when the temperature goes up for few degrees, the AC will go on again.
Failing to turn off the AC when the preset temperature is achieved means that the AC will work longer without a real need for it to do so, and this translate into a higher electric bill because of this fault in the thermostat.
Again, this also applies to a central heating system that uses gas or diesel as a fuel, where the faulty thermostat will increase the fuel consumption, in addition into increasing the electric bill by running the pumps for longer hours.
This fault makes the thermostat turn on and off the AC or the central heating more frequently than it should, and it will prevent the space from reaching the desired temperature,
This might lead to having the system operating at a lower efficiency, and thus, using more energy and fuel as a result.
Or maybe, because the short cycle will make it difficult to achieve the desired temperature, people will start increasing or decreasing the preset temperature in a way that would force the system to consume more energy during its operation.
Does Not Respond to Changes on Settings
One of the faults that can cause a thermostat to increase electric bill is that when it stops responding to changes in settings you make to it.
Maybe it was set by someone else at 78 F, and you are trying to change the temperature to 81 F because you feel that it is a bit cold for you, but it the thermostat couldn’t respond to the changes you are trying to make.
As will make it run and try to achieve a temperature level that you don’t want it to achieve, which will increase the energy bill and will make you feel uncomfortable.
Not Following Timing for Smart Thermostats
Smart programmable thermostats are designed to allow you to run the heating and cooling systems based on a preset schedule and temperature degrees.
For example, you could time the thermostat to turn on the heating or cooling just thirty minutes before you arrive home coming back from work every day.
Imagine if the thermostat doesn’t follow the schedule properly and decides to turn on the AC five hours before you come back home!
Or maybe you set it to turn off one hour after you go to bed, but it keeps the AC running until morning.
This thermostat fault might be a reason to literally double the heating or cooling bill and to increase energy bills as a result.
Conclusion – It Is Always Worth it to Fix a Broken Thermostat
It is always to recommended fixing a faulty thermostat in order to save money on air conditioning and heating bills.
The small investment for fixing or replacing the bad thermostat will be offset by the savings you make on electric and energy bills.
You may call a specialized technician in order to troubleshoot the thermostat for you and fix it or give you expert advice on a better replacement.
And you may consider investing in a smart thermostat that can be controlled from to your phone through the WiFi network like the Ecobee thermostat, which can be a big money saver and allows for more convenience in running and controlling your heating and cooling systems.
I hope that this article was helpful for you in seeing how a faulty thermostat can cause a high electricity bill.
If you still need help regarding anything in this article, please, ask me in the comments’ section below, and I will do my best to help you out 🙂