Best Whole-House Surge Protectors

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Since the 2020 NEC, new and replaced dwelling services are required to have surge protection (NEC 230.67). Most homeowners meet it with a Type 2 SPD at the panel — a device that clamps large transients arriving on the service conductors before they reach your branch circuits.

The spec that matters most is not the headline kA number. Voltage protection rating (VPR) — the let-through voltage during a standard test surge — is what decides how well your equipment is protected, and it is where products genuinely differ. Surge current capacity decides longevity: a bigger reservoir of MOVs degrades more slowly.

This page compares devices on manufacturer-published figures only: SPD type, VPR, surge current rating, enclosure, indicators and warranty terms. Every whole-house SPD here requires installation in or beside an energized panel, which makes it electrician work — a short job, cheapest bundled with any other panel visit.

How we picked

UL 1449 listed, with the SPD Type (1, 2 or 3) the location calls for
Low VPR — the let-through voltage matters more than the kA headline
Status indication you can actually see, because SPDs fail silently
Warranty terms that don't collapse under their own conditions

We do not accept payment for placement and we do not publish star ratings we did not measure. Specifications come from each manufacturer's published spec sheet.

Side by side

Product	Type	Best for	Indicators	Warranty	SPD Type	Surge capacity	Nominal discharge (In)	VPR	Enclosure	SCCR
Siemens BoltShield FSPD140	Type 2 whole-house SPD	The default whole-house pick on any brand of panel	Status LEDs + red alarm LED + audible alarm	10 years, $100,000 connected equipment	Type 2 (UL 1449 5th Ed.)	140 kA	20 kA	700 V L-N / 700 V L-G / 700 V N-G / 1200 V L-L	NEMA 4X polycarbonate	200 kA
Eaton CHSPT2ULTRA	Type 2 whole-house SPD	A lifetime-warranty alternative at the top of the market	LED protective status	Lifetime device, up to $75,000 connected equipment	Type 2	108 kA per phase	20 kA	600 V L-N / 600 V L-G / 800 V N-G / 1000 V L-L	NEMA 4	—
Square D HEPD80	Type 1 whole-house SPD	The proven value pick, especially on Square D panels	Single green LED	5 years	Type 1 (UL 1449 4th Ed.)	80 kA per phase	10 kA	600 V L-N / 600 V L-G / 900 V N-G / 1000 V L-L	NEMA 4X non-metallic	25 kA
Leviton P2120-B	Type 1 service-entrance SPD	Service-entrance installs and meter-adjacent mounting	Status LEDs + audible alarm + Form C contacts	5-year limited	Type 1 (UL 1449 5th Ed. 2021)	50 kA per phase	20 kA	700 V L-N / 1200 V L-G / 600 V N-G / 1200 V L-L	NEMA 4X polycarbonate	200 kA
Intermatic AG3000	HVAC surge protector	Adding a protection layer at the AC condenser or heat pump	Single green LED	3 years, $7,500 connected equipment	Type 1 or 2 (UL 1449 4th Ed.)	50 kA	20 kA	700 V L-N / 1200 V L-L	Type 4X outdoor, UV resistant	200 kA
Tripp Lite by Eaton ISOBAR6ULTRA	Type 3 point-of-use	The point-of-use layer at your electronics	Protection present / line fault / line OK LEDs	Lifetime, $50,000 insurance	—	—	—	—	—	—

The picks

#1 · Type 2 whole-house SPD

Siemens BoltShield FSPD140

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Siemens' current flagship residential SPD — 140 kA, 20 kA nominal discharge, audible alarm, and the strongest warranty terms in the group.

Best for: The default whole-house pick on any brand of panel

SPD Type: Type 2 (UL 1449 5th Ed.)
Surge capacity: 140 kA
Nominal discharge (In): 20 kA
VPR: 700 V L-N / 700 V L-G / 700 V N-G / 1200 V L-L
SCCR: 200 kA
Enclosure: NEMA 4X polycarbonate
Indicators: Status LEDs + red alarm LED + audible alarm
Warranty: 10 years, $100,000 connected equipment

20 kA nominal discharge rating — comfortably above the 2023 NEC 242.10 dwelling minimum
Audible alarm and ground-reference monitoring, so a failed unit announces itself
Mounts beside any manufacturer's load center, not just Siemens panels

Successor to the discontinued FS140 — retailers still sell the old model, so check the box says FSPD140
External mount needs a knockout and a 2-pole breaker's worth of electrician time

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#2 · Type 2 whole-house SPD

Eaton CHSPT2ULTRA

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Eaton's flagship Type 2 with a lifetime device warranty and up to $75,000 connected-equipment coverage.

Best for: A lifetime-warranty alternative at the top of the market

SPD Type: Type 2
Surge capacity: 108 kA per phase
Nominal discharge (In): 20 kA
VPR: 600 V L-N / 600 V L-G / 800 V N-G / 1000 V L-L
Enclosure: NEMA 4
Indicators: LED protective status
Warranty: Lifetime device, up to $75,000 connected equipment

Best published VPR of the whole-house group — 600 V let-through L-N
Lifetime device warranty, unusual in this category
Fits beside any manufacturer's load center via a 2-pole 50 A breaker

No audible alarm — you have to look at the LED to know it's still protecting
Eaton's own page is inconsistent on SCCR (22 kA vs 200 kAIC) — ask your electrician to verify against the label

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#3 · Type 1 whole-house SPD

Square D HEPD80

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The ubiquitous compact SPD — Type 1 rated, 80 kA per phase, and the one your electrician has probably installed fifty times.

Best for: The proven value pick, especially on Square D panels

SPD Type: Type 1 (UL 1449 4th Ed.)
Surge capacity: 80 kA per phase
Nominal discharge (In): 10 kA
VPR: 600 V L-N / 600 V L-G / 900 V N-G / 1000 V L-L
SCCR: 25 kA
Enclosure: NEMA 4X non-metallic
Indicators: Single green LED
Warranty: 5 years

Type 1 listing allows line-side installation, not just load-side
600 V let-through matches devices costing twice as much
Small, familiar, and stocked everywhere electricians shop

10 kA In is the NEC dwelling minimum, not headroom above it
One unlabeled LED and no alarm — easy to miss a failure
Connected-equipment coverage not published; 5-year term trails the leaders

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#4 · Type 1 service-entrance SPD

Leviton P2120-B

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A current Type 1 SPD listed to UL 1449 5th Edition, with an audible alarm, phase-loss monitoring and dry contacts.

Best for: Service-entrance installs and meter-adjacent mounting

SPD Type: Type 1 (UL 1449 5th Ed. 2021)
Surge capacity: 50 kA per phase
Nominal discharge (In): 20 kA
VPR: 700 V L-N / 1200 V L-G / 600 V N-G / 1200 V L-L
SCCR: 200 kA
Enclosure: NEMA 4X polycarbonate
Indicators: Status LEDs + audible alarm + Form C contacts
Warranty: 5-year limited

True Type 1 listing for line-side-of-the-disconnect installation
Audible alarm plus dry contacts you can wire to an alert
200 kA SCCR and current 5th-edition UL listing

50 kA headline capacity is the smallest of the whole-house group
Connected-equipment coverage not published for the P Series

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#5 · HVAC surge protector

Intermatic AG3000

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A compact SPD that mounts on the outdoor AC disconnect, protecting the most expensive motor load in the house at its own connection point.

Best for: Adding a protection layer at the AC condenser or heat pump

SPD Type: Type 1 or 2 (UL 1449 4th Ed.)
Surge capacity: 50 kA
Nominal discharge (In): 20 kA
VPR: 700 V L-N / 1200 V L-L
SCCR: 200 kA
Enclosure: Type 4X outdoor, UV resistant
Indicators: Single green LED
Warranty: 3 years, $7,500 connected equipment

Protects the compressor and its board right at the disconnect, downstream of everything else
TPMOV design fails open rather than on fire — its own selling point in a plastic box on a wall
Trivial add-on during any AC or heat pump service call

Not a whole-house device — it's a layer for one circuit
Shortest warranty of the group

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#6 · Type 3 point-of-use

Tripp Lite by Eaton ISOBAR6ULTRA

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The metal-cased reference point-of-use strip — 3,330 joules, isolated filter banks, and a $50,000 insurance policy.

Best for: The point-of-use layer at your electronics

Rating: 3,330 joules, 6 outlets
UL 1449: Listed, 5th Ed. 2021
Let-through: 330 V UL 1449 rating
Filtering: 3 isolated banks, EMI/RFI filtered
Indicators: Protection present / line fault / line OK LEDs
Build: Metal housing, 6 ft cord, 12 A breaker
Warranty: Lifetime, $50,000 insurance

All-metal build in a category of disposable plastic strips
Diagnostic LEDs actually tell you protection state and wiring faults
Isolated filter banks keep noisy loads from polluting quiet ones

Point-of-use only — the last layer, not the first
Bulky right-angle plug and metal chassis won't hide behind furniture

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Working out what you need before you buy? Read the electrical panels & circuits guides.