There’s a very Arizona moment that happens every fall.

After months of your air conditioner doing all the heavy lifting, we finally get one of those cooler mornings. You walk over to the thermostat, switch the system from COOL to HEAT for the first time in months and a few minutes later…

What is that smell?

If you’ve lived in the Valley long enough, you may know exactly what we’re talking about.

That first heater run of the season can come with a dusty or slightly burnt smell that makes homeowners wonder whether something is wrong. Sometimes, it’s completely normal.

Other times, your HVAC system may actually be trying to tell you something.

Here’s how to know the difference.

Why Your Heater Can Smell the First Time You Turn It On

Think about what your heating system has been doing for the last several months.

Not much.

While your AC has been battling another Arizona summer, portions of your heating system have essentially been waiting for their turn. During that time, dust and debris can settle on components inside the system.

When the heat comes on for the first time, that accumulated dust can warm up and create a temporary dusty or burning smell.

In many homes, the smell fades fairly quickly as the system runs.

So if you turn your heat on for the first time this fall and notice a mild dusty smell that disappears, there may not be any reason to panic.

But the important word there is disappears.

When a Burning Smell ISN’T Something to Ignore

A smell that continues, gets stronger or smells distinctly electrical is a different story.

Pay attention if you notice:

• A strong electrical or plastic-burning odor
• Smoke coming from a vent or HVAC equipment
• A smell that doesn’t go away after the system has been running
• Unusual noises when the heat starts
• The system repeatedly turning on and off
• A heater that runs but doesn’t seem to warm the home
• A breaker that trips after the heating system starts

Those aren’t things to simply wait out.

If something seems unusual, turn the system off and have it checked rather than continuing to run it and hoping the problem disappears.

Arizona Is Hard on HVAC Systems — Even Before Heating Season

Here’s something that’s easy to forget.

Your heating and cooling equipment doesn’t experience two completely separate lives.

Your HVAC system just spent months operating through Phoenix’s most demanding season. Extreme heat, dust and long run times can expose weaknesses that weren’t obvious earlier in the year.

Then suddenly, you’re asking the system to operate differently.

That makes the transition between cooling and heating a useful time to pay attention.

Does the thermostat respond correctly?

Does the system start normally?

Is airflow strong?

Are there strange noises?

Does the house actually get warmer?

And yes — does anything smell unusual?

You don’t have to be an HVAC technician to notice when something seems different than it did last year.

Don’t Wait for the First Actually Cold Morning

This is probably the biggest mistake Arizona homeowners make with their heaters.

Nobody thinks about heating when it’s still warm outside.

Then we get our first genuinely chilly morning and thousands of homeowners across the Valley seem to have the same thought at once:

“Maybe I should make sure the heater works.”

There’s a much easier approach.

Test it before you need it.

Pick a cooler morning or evening this fall and turn the heat on for a short period. Give the system a chance to run and make sure everything appears to be operating normally.

If there’s a problem, you’d probably rather discover it now than on the morning your family actually wants heat.

What About That Dusty Smell Coming From the Vents?

Your HVAC system moves air throughout your home, so the first heating cycle can also stir up dust that has accumulated around registers, returns and other areas.

Fall is a good opportunity to look around your home and check a few simple things.

Make sure vents aren’t blocked by furniture or rugs. Take a look at your air filter and replace it when needed. Vacuum dust around accessible registers and returns.

These aren’t complicated projects, but they’re easy to forget after months of focusing almost entirely on surviving the summer heat.

Your Thermostat Deserves a Quick Check Too

The seasonal change is also a good time to make sure your thermostat is behaving normally.

Switch from cooling to heating and pay attention to what happens.

Does the system respond?

Does it reach the temperature you’ve selected?

Does it seem to run much longer than expected?

If you use schedules or a smart thermostat, this is also a good time to update those settings for cooler weather.

Phoenix doesn’t require the same heating schedule as colder parts of the country, so there’s no reason to leave your thermostat programmed as though January in Arizona is January in Minnesota.

The Best Time to Find a Heating Problem Is Before You Need Heat

We spend a lot of time talking about air conditioning in Arizona — and for good reason.

But your HVAC system still has another job to do.

The first time you turn on the heat this fall is essentially your system’s first test after months on the sidelines. A little temporary dusty smell may simply be part of that transition.

A strong, persistent or unusual smell deserves more attention.

And if your heater isn’t working the way you remember, there’s no advantage to waiting until temperatures drop further to find out why.

Forrest Anderson Plumbing & Air Conditioning has served Phoenix-area homeowners since 1961, with heating and cooling services becoming part of the family business in the 1970s.

If something doesn’t seem right when you turn your heat on this fall, give the Forrest Anderson team a call at 623-780-4060 and get it checked before those cooler Arizona mornings arrive.