Thermostats last 8-12 years. Factors are initial quality, maintenance, home conditions and whether any electrical issues in the home damage the thermostat.
How Long Does a Furnace Thermostat Last?
Furnace thermostat durability is usually at least 8 years, and some last more than 12 years.
If the thermostat is installed new along with the furnace, and you don’t want to upgrade it, then expect 10+ years of use without issues. This is true unless it is a cheap thermostat to begin with. Then it might last 5-8 years.
You can get the best longevity from a furnace thermostat by keeping it dusted – including removing the cover and gently dusting or vacuuming the interior wiring.
Placing it where it won’t get frequently bumped or jarred will encourage longer life too.
Also, “set it and forget it.” Some HVAC experts state that changing the program frequently might cause it to fail prematurely. But the evidence isn’t strong that adjusting thermostat settings shortens its lifespan.
Thermostat Longevity by Brand
Your best bet for a long-lasting thermostat is to buy a brand recognized for quality. Here are a couple of examples.
Honeywell makes a wide range of thermostats. A Honeywell thermostat lasts 5-15 years based on quality and how you care for it including dusting, avoiding damage and keeping the batteries fresh.
Today’s digital Honeywell thermostats have a longevity of 10+ years when you buy a quality model. This is true for White Rodgers, Emerson and similar brands.
Nest thermostat units including Gen 2 and Gen 3 nest thermostats last 7-10 years – or are expected to. Of course, they haven’t been around long enough to have clear durability data. The same is true for ecobee and Lux Geo thermostats.
Insight: Research shows that nest thermostats often last fewer years than that – not because of mechanical problems, but because homeowners get frustrated with the “learning” process of the nest.
The nest thermostats and other smart thermostats tend to correct too much, and homeowners get frustrated and end up feeling like the nest is trying to teach them rather than the other way around. Plus, they can be complicated to change to accommodate an advanced HVAC system.
To avoid unnecessary frustration and getting rid of the nest sooner rather than later, thoroughly educate yourself about how to use it.
Digital vs Analog Thermostat Longevity
Very few of the old-style analog thermostats are installed today. Those in use last 10-20 years.
How long does a digital thermostat last? Expect 5 years from cheap models and 7-12 years from those from quality brands like Honeywell, Emerson and nest.
This is generally true whether you choose a non-programmable or programmable thermostat. However, the cheapest thermostats, those that don’t last very long, are almost always digital non-programmable.
How long does a water heater thermostat last: Odd question here, but it occasionally comes up in search results for thermostat longevity.
So, in case you’re here for that question, the answer is that a water heater thermostat lasts 4-10 years with an average of about 6-7 years.
What About Thermostat Batteries?
Thermostat batteries last 6 to 15 months depending on the quality of the battery and how much you adjust your thermostat. The average is 10-12 months.
If your thermostat has a low-battery indicator light, pay attention to it. Changing the batteries before they run out of juice can prevent you from losing all your programmed settings.
How to Know When to Replace a Thermostat
There are mechanical and practical reasons to consider thermostat replacement.
When it’s dead, it’s dead. If your thermostat doesn’t have power, and you or a service technician determine it is getting power, it means the internals of the thermostat are shot. It is replacement time.
Remember: Check the batteries before calling a technician!
When it quits intermittently. It works and then it doesn’t. Again, if power to it is not the issue, the wiring is going, and it should be replaced.
When it isn’t “acting right.” If it isn’t turning on your system or won’t shut it down when it should, it’s bad. In other words, if the temperature in your home doesn’t match what it says on the thermostat, it is time for a new thermostat.
Your HVAC system doesn’t respond. If you adjust the setting on the thermostat, and “nothing happens,” it could be a thermostat fault issue.
Your energy bills are rising for no good reason. The thermostat could be causing the system to turn on and off too often.
That is called short-cycling. It might or might not affect the temperature in your home, but it will affect your energy cost.
You buy a new system, and a new thermostat is required. For example, if you upgrade to a multistage system or from a furnace to a heat pump system, you will need a new thermostat to control it.
You want to upgrade to a programmable thermostat to save money. You can do this by programming the thermostat to run the system less during the night or when you’re away for the day.
You want a smart thermostat or a WiFi thermostat – or both.
You like the idea of having service alerts. Many quality thermostats available now give notifications that your furnace filter is dirty or that, for another reason, your system requires maintenance.