Surge protectors keep sudden spikes of electricity from damaging sensitive electronics. As heating and air conditioning systems become increasingly sophisticated, they’re also becoming more vulnerable to damage from sudden power surges. If your area sees power outages, your HVAC system’s electronics can be at risk when the power drops and comes back.
A surge protector can help keep your HVAC equipment safe when the grid misbehaves. For homeowners with heat pumps and ductless mini-split systems, a surge protector can be especially useful in protecting their circuit boards and electronics. Find out how surge protectors work and how they can protect your equipment when it’s most at risk.
What is a surge protector?
A surge protector is a device added to your home’s electrical system, either at the main panel to cover the whole house or at the HVAC equipment itself. Most use metal oxide varistors (MOVs), parts that do nothing at normal voltage but conduct when voltage spikes, sending the extra energy to ground instead of through your equipment.
Many modern units use thermally protected MOVs (TMOVs), which safely disconnect themselves if they overheat after absorbing a large surge.
Surge protectors may also include gas discharge tubes (GDTs). These are filled with inert gas and help the surge protector handle larger bursts of energy.
What causes power surges?
A power surge is a brief burst of voltage far above what your equipment is designed for. Most heat pumps and AC outdoor units run on a 240-volt circuit. Surges are very short, but they can still damage unprotected electronics. Some of the most common causes are:
- Lightning: Power lines struck by lightning can send sudden uncontrolled power surges into connected homes.
- Grid problems: Anything that damages the grid, such as utility work, car accidents, debris strikes, or animals in equipment, can set off power surges.
- Power coming back after an outage: When the power is restored, the sudden return of voltage can spike.
- Home appliances: Many surges start inside the home, when large appliances and motors switch on and off.
Power surges are common for many households. Unfortunately, that puts some of the most sensitive components of your HVAC system at risk, including the circuit boards in your heat pump and mini-split.
How does a surge protector protect an HVAC system?
It diverts the extra voltage away from the equipment. An HVAC system is like any other appliance in your house. A surge protector redirects excess current into a ground wire, away from your HVAC system. This is especially useful for systems with sensitive electronics, such as mini-splits and heat pumps.
| Equipment | What a surge can damage |
|---|---|
| Heat pump | Control boards, motor wiring, and the electronics that run variable-speed compressors |
| Ductless mini-split | The inverter board in the outdoor unit and the control boards in each indoor unit |
| Thermostat | Smart and communicating thermostats connected to the system |
How can a surge protector save my heat pump or mini-split?
Power surges can damage the electrical wiring and control boards that run a heat pump’s motors. Outages and storms often happen when you need heating or cooling most, and a damaged heat pump can leave your home without either until it is repaired.
Mini-splits rely on compact, sensitive electronics, which makes them especially vulnerable to power surges. An unprotected mini-split can lose its circuit boards to a single surge.
Key takeaway: A surge protector is a small add-on that helps protect the electronics in heat pumps and mini-splits. Ask your technician whether one makes sense for your system during your next maintenance visit or installation.
Should I add a surge protector to my HVAC system?
If you have a heat pump or mini-split, it’s worth considering. Installing surge protection for your HVAC system and its major components can help protect against electrical surges and the cost of replacing damaged parts, and keep your home comfortable through storm season.
Upgrade Home Services installs, repairs and maintains heat pumps and ductless mini-splits from Milpitas. We’re a family-owned HVAC contractor, licensed by the CSLB (#1066776) and serving homeowners since 2002 in 22 cities across Santa Clara, San Mateo and southern Alameda counties.
HVAC surge protector questions
Do I need a surge protector for my heat pump?
It’s not required, but it’s worth considering. Heat pumps rely on circuit boards and variable-speed electronics that a surge can damage, and a surge protector is a small add-on compared with replacing those parts.
Where is an HVAC surge protector installed?
Usually at the outdoor unit’s electrical disconnect, or at the main electrical panel as a whole-home protector. Some homes use both.
Does a whole-home surge protector cover my HVAC system?
It helps with surges coming in from the grid. Surges that start inside the home, from appliances switching on and off, may not pass through it, which is why some homeowners also add one at the HVAC equipment.
Do mini-splits need surge protection?
Mini-splits use inverter boards and other compact electronics, so surge protection is a good idea for them. Ask us about it during installation or maintenance.
Questions about your system?
Upgrade Home Services is family-owned in Milpitas since 2002. Licensed, CSLB #1066776 · B, C-20. Free estimates on new and replacement systems.