Winter is loosening its grip, spring is right around the corner, and here in the Midwest that means one thing with absolute certainty: weather. Thunderstorms, wind, lightning, grid hiccups, and power events that make your lights flicker just enough to get your attention.
If you’ve lived here long enough, you’ve seen it. And if you work in HVAC long enough like we have, you’ve fixed the aftermath.
As an HVAC business, we’ve pretty much seen it all. Burnt boards. Dead inverters. Systems that worked yesterday and are completely lifeless today. In many cases, the culprit is not the equipment itself but what came through the power lines.
Modern HVAC systems are no longer simple motors and relays. They are computers that just happen to make you comfortable. And computers do not forgive dirty power.
This is why surge protection is not optional anymore.
“Letting the Smoke Out” and Why That’s Bad
For the non-technical crowd, there is a universal truth in electronics: once the smoke comes out, it does not go back in.
When a voltage spike or abnormal power event hits an HVAC system, the most common casualty is the control board or inverter board. These are the brains of the system. When they fail, the system stops. Period.
Replacing those boards is not cheap, often running into the thousands of dollars when parts and labor are combined. And no, the warranty fairy does not always show up when the damage is electrical.
Spring Storms Are Only Part of the Problem
Lightning gets most of the attention, and yes, it can absolutely destroy HVAC electronics. But here’s the part most people miss.
You do not need lightning to have destructive voltage events.
Across the country, power quality issues happen every day due to:
- Utility switching operations
- Grid load changes during peak demand
- Large motors cycling on and off
- Nearby industrial equipment
- Transformer issues
- Lost or floating neutrals
In fact, the majority of damaging surges originate inside buildings, not from storms.
So even if you live in an area where lightning is rare, your system is still exposed.
Why Inverter-Driven HVAC Systems Are More Vulnerable
Modern MRCOOL and other inverter-driven HVAC systems are incredibly efficient. That efficiency comes from advanced electronics that tightly control compressor speed and system operation.
These systems rely on:
- Rectifiers converting AC to DC
- Inverter circuits using IGBTs
- Microprocessors managing every function
- DC bus capacitors maintaining stable voltage
All of those components operate within narrow electrical tolerances. When power quality falls outside those limits, damage happens fast.
Older equipment might limp along under bad power conditions. Inverter systems either shut down to protect themselves or fail outright.
The Three Power Problems That Kill HVAC Electronics
1. Surge Transients
Surge transients are short, high-voltage spikes lasting microseconds to milliseconds. They can come from lightning, grid switching, or equipment cycling.
One surge is all it takes to:
- Punch through IGBT insulation
- Corrupt control board firmware
- Destroy gate drivers
- Damage DC bus capacitors
Board replacement costs commonly range from $1,500 to $5,000 or more. That is not a theoretical number. We see it in the real world.
2. Brownouts and Undervoltage
Voltage sags and brownouts happen far more often than full outages. During these events:
- Inverter systems draw higher current
- Semiconductor components overheat
- Compressors can lose torque and stall
- Systems shut down to protect themselves
Repeated brownouts cause cumulative damage, shortening the life of capacitors and power electronics even if the system keeps running for a while.
3. Extended Overvoltage
Sustained voltage that runs just a little high may not cause immediate failure, but it silently destroys equipment over time.
Extended overvoltage:
- Accelerates capacitor wear
- Increases heat in inverter components
- Breaks down insulation
A system designed to last 15 years can be cut nearly in half when exposed to chronic overvoltage.
Why We Trust RectorSeal Surge Protection
We are not fans of cutting corners where it matters. After years of trial, error, and expensive lessons, one thing is clear.
Surge protection is not the place to save a few dollars.
Dollar for dollar, the best surge protection products we have used are made by RectorSeal. Their HVAC-focused protection products are engineered specifically for modern inverter-driven systems, not generic electrical loads.
We believe in their product line because it works. Plain and simple.
What Makes RectorSeal RSH™ Different
RectorSeal RSH™ surge protection and voltage monitoring products are designed for HVAC environments, not adapted after the fact.
Key benefits include:
- HVAC-optimized clamping voltages
- Fast response times to divert surges before damage occurs
- Protection against surges, undervoltage, and overvoltage
- Visual status indicators so protection is never a mystery
- UL 1449 5th Edition listing
- Proven reliability in outdoor installations
These products act as a buffer between unstable utility power and your HVAC system’s electronics.
Not an Accessory. Insurance.
Surge protection is not a flashy upgrade. It does not make your system quieter or colder or more efficient.
What it does is protect the most expensive and sensitive parts of your HVAC system from events you cannot control.
In an era where HVAC equipment is essentially a computer with a compressor attached, protecting power quality is just part of responsible ownership.
We have learned the hard way so you don’t have to.
Final Thoughts
As we move quickly out of winter and into storm season, now is the time to think about protecting your investment.
Whether you live in the Midwest with frequent thunderstorms or anywhere else in the country with an aging power grid, voltage problems are not a matter of if. They are a matter of when.
Surge protection and voltage monitoring are not optional add-ons anymore. They are essential.
Protect your equipment. Protect your wallet. Protect your comfort.
We trust RectorSeal because they have earned it.