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Why Is My Thermostat Not Working?

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Winter has to be the worst season for your heating system to fail. No matter how much you tinker with your thermostat setting, your room still feels as cold as ever.

Now you're wondering what's wrong with your thermostat. Why can't you adjust your thermostat setting? Why is your AC thermostat not working? Do you need a new HVAC system?

It's understandable that you are feeling a little lost. Not everyone knows how to deal with a faulty thermostat. Not everyone has the time or mental space to tinker with their thermostat either.

We're here to talk about the reasons why you have a faulty thermostat. What to do when your thermostat fails, and who to call to fix it.

Ready to learn more? Then keep on reading!

How Do Digital Thermostats Work?

A thermostat is a piece built into any system that heats or cools to a certain set temperature. It detects temperature changes and regulates the temperatures in a heating system. Some examples of devices that use thermostats are your furnace, air conditioning unit, and water heaters.

Digital or programmable thermostats automatically adjust temperatures to your desired settings. You simply enter your preferred temperature and your thermostat will handle the rest.

For example, you can lower the temperature during warmer days and you can set the temperature higher when the days are colder. You can even set your digital thermostat to change temperatures throughout the day.

Once you have set up your desired temperatures, your thermostat will monitor your heating and cooling system’s progress and stop the heating/cooling right before your unit overheats.

In order to be able to “sense” that the HVAC system has reached the right heat settings, a digital thermostat has a built-in component called the thermistor.

Thermistors are components that measure temperatures based on the pre-programmed settings on your thermostat. It contains metals that change as the ambient temperature changes.

Reasons Why Your Thermostat Isn't Working

Faulty HVAC systems are frustrating to deal with. You're not sure how to troubleshoot it, whether or not you need to buy a new thermostat, or if you just need to replace some dead batteries.

There could be many causes behind your thermostat issues. But this is why we're here.

So let's get to know the common reasons why you are having thermostat issues:

You Have It On the Wrong Temperature Setting

We sometimes forget to change our thermostat settings. If your unit is not warming your place properly, check if your thermostat is on your desired temperature settings.

If it's not, simply input your desired temperature settings. You can refer to your owner's manual on how to calibrate your thermostat.

Your Thermostat is Dirty

Just like most devices, your HVAC system can have some problems if it gets too dirty. Accumulated dirt, dust, and other debris can stop your electrical components from working properly.

Check if you have a dirty thermostat by opening the thermostat's cover. Use a soft brush to dust off any dirt and debris that you find inside. Once you're done, simply re-attach the cover and switch on your unit.

If your thermostat was simply blocked by dirt build-up, it should get back to working good as new after you clean it.

Loose Wires and Corroded Pieces

Your thermostat's wiring will eventually come loose. That's normal for most electronics, so you shouldn't worry too much.

Over time, the wiring that runs through your thermostat's entire system can loosen and cause it to malfunction. If it is a matter of loose screws, you can simply tighten those yourself.

Corroded and detached wires, on the other hand, are a different issue. When it comes to your thermostat's control systems, you will need the help of an HVAC professional.

We do not recommend that you fix your thermostat's loose wiring without the right skills and knowledge.

If you accidentally cut off a wire or misplace an important piece, your thermostat could be rendered useless, and that's not what we want.

You reduce the risk of damaging your thermostat if you let an HVAC professional handle the fixing.

Your Thermostat is Installed Close to a Heat Source

Did you know that where you put your thermostat matters? Your thermostat is a lot more sensitive than you think.

If your thermostat is exposed to external heat sources, it will not be able to accurately detect the warmth in a space. Yes, this can be true for digital thermostats too.

For instance, if your thermostat is installed close to a window or a door, it might shut off prematurely as it is sensing the warmth from the outdoors.

This can "trick" your thermostat and cause it to shut down before it reaches your actual temperature settings.

Not only will this cause cold spots and inefficient heating in your home, but it can eventually raise your electricity bills due to frequent cycling.

You Have Dead Batteries

Your thermostat's battery only needs to be replaced once a year. This makes it very easy to forget. If you keep seeing an "error" on your thermostat's display, it's time to install new batteries.

Changing your thermostat's batteries is simple and won't take you too long to do. But if you're not familiar with thermostats, you can always call an HVAC technician for a simple fix.

If switching out the battery doesn't work, you might have a blown fuse or tripped circuit breaker.

The Thermostat is Not Level with the Wall

Is your thermostat showing a different temperature reading from your room's actual temperature?

If you have an older mercury thermostat, this can mean that it may not be properly leveled to your wall. Your thermostat's mercury bulb relies on being leveled to a wall in order to operate.

Don't worry, all you have to do is to switch off your thermostat's power supply, unmount it, and use a leveling tool when you remount.

To make life even easier, we suggest that you switch to digital thermostats. Not only are they easier to read, they’re also much safer to have in your home.

Should You Replace Your Thermostat?

We understand how frustrating it is to deal with a malfunctioning thermostat. But you do not have to replace it as soon as it stops working.

Thermostats and thermostat installation will cost you. So you shouldn’t be too quick to buy a new thermostat the moment the one you currently have starts to malfunction.

That said, there will come a day when you will need a replacement. So how can you tell if it's time to get a new thermostat? Here are some signs:

It's Old

Thermostats were made to last about 10 years of use. If your thermostat is older than that, then you should look into getting a new one before you experience temperature problems.

In fact, we encourage you to replace your thermostat before it reaches its 10-year mark.

The Readings are Always Wrong

Your thermostat should be able to get accurate readings to make sure that your home is not too hot or too cold.

If your thermostat is always getting the wrong temperature reading, you might need a replacement.

Costly Utility Bills

A thermostat that has loose wiring or a blown circuit breaker will either overheat or cause temperature discrepancies in your home.

Because the thermostat needs to exert more effort to produce hot air, it will eat up more energy. This will increase your electricity bills.

Frequent Short Cycling

Short cycling happens when your furnace shuts off before completing its cycle. This is one of the most common reasons for replacing thermostats.

This means that your thermostat is "telling" your heat anticipator to shut off even if the thermostat set temperature has not been achieved.

If this is the case, it means that you need to call a professional to solve your thermostat issue.

Ignoring your thermostat’s short cycling can eventually raise your utility bills. With how expensive everything is right now, the last thing you want is for your household bills to get higher.

Keeping Your Thermostat In Working Condition

Your thermostat needs to be professionally maintained too. This is to prolong the lifespan of your unit.

Yes, thermostats are made to last you at least a decade of use, but they need proper care too. Regular maintenance is one way to make the most out of your heating and air conditioner units.

Thermostats may seem like a small piece in your entire HVAC system, but it serves a large purpose. While thermostats are generally affordable, it can still be a pain in the neck to always need to replace them regularly.

If you’re not familiar with thermostats and how to properly install them, you’ll probably end up calling in help from professionals. That's an added cost!

Through regular cleaning and maintenance, you can prolong your thermostat’s lifespan.

HVAC Specialists at Your Service

It won't be easy to manage your thermostat alone if you don't have the right know-how. Luckily, there are many HVAC service providers in Portland, Oregon.

We have many HVAC services available to suit your every need. Be it furnace repairs, air conditioner replacements, a furnace tune-up, and more. We've got your back.

Get in touch with us at (503) 500-5866

We'll handle the heavy lifting. Just sit back, relax, and keep warm for the winter!

What Our Clients Say

Sunset went out of their way to help with my project and David was amazing. Great job and look forward to future projects.

-Todd T.

Roman did an awesome job. I had the trifecta, new AC unit ,furnace and hot water heater. Courteous, and competent service. I highly recommend Sunset Heating & Cooling.

-Charles E.

Eduardo provided excellent service when he repaired our AC. I felt his effort was over and above expected. Polite and professional at all times. Good job!

-William G.

Caring, professional and helpful. Thanks for making things happen quickly and getting my Dear friend's heating back up and running in such a quick manner. You went above and beyond for a family in need and that is very much appreciated. Thanks from the whole group!

-Kristina K.

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