Find My Generator
finder
Back to catalog

FIRMAN · Inverter generator

WT03571

4,400 starting watts and 3,500 running watts with gasoline, propane, natural gas operation.

3,500W running4,400W starting64dB at 1/4 loadGasoline + Propane + Natural gas
Check FIRMAN price Available

$1,129.99

Direct price snapshot
FIRMAN Tri Fuel Inverter Portable Generator 4400/3500W Electric Start 120V Parallel Ready CO Alert
Official product image: FIRMAN

Product decision summary

Researched by · reviewed under the FMG editorial standard · Sep 15, 2026

Trace the evidence · not a hands-on review

Bottom line

Best for specific needs for camping & home projects.

Best for: Camping & Home Projects

Running output

3,500W

Fuel / power

Gasoline + Propane + Natural gas

Weight

52 lb

Strongest reasons

  • 4,400 starting watts and 3,500 running watts with gasoline, propane, natural gas operation.
  • Product weight is lighter than 93% of its class.
  • Multiple fuel choices add outage flexibility.

Know before buying

Confirm the outlet mix, transfer-equipment needs, runtime test load, and local service coverage before buying.

Best current buying route

$1,130

Observed price at FIRMAN

The only verified seller destination. Its listed price is known, but shipping and delivered cost still need confirmation. Confirm price, stock, shipping, and the exact model on the seller’s site.

Check price & availability

Affiliate links may earn us a commission at no added cost to you. Disclosure

Never run a fuel-burning generator in a home, garage, shed, or other enclosed or partly enclosed space.

Price intelligence Evidence ledger Accessories & manuals

Key specifications

The numbers that drive the decision.

Published values stay labeled, and every usable metric includes class context. Missing data is shown instead of estimated.

Open complete specifications
SpecificationThis model
Running output3,500WHigher than 46% of its class
Peak / starting output4,400WHigher than 45% of its class
Published runtime8 hrLonger than 23% of its class
Product weight52 lbLighter than 93% of its class
Published sound level64 dBAQuieter than 27% of its class
Fuel / power sourceGasoline + Propane + Natural gasInverter generator
Best current price$1,130Observed price at FIRMAN

Class comparisons use 177 mid output inverter generators. Runtime figures can use different loads, fuels, or test conditions; confirm the model manual before planning fuel or battery duration.

Product gallery & complete specifications Official imagery, full spec tables, use cases, and source linksView details

Visual spec gallery

Core specifications, simplified.

01 · Output by fuel

Up to 4,400 starting watts

Gasoline3,500W running

4,400W starting

Propane3,200W running

4,000W starting

Natural gas2,800W running

3,500W starting

02 · Runtime & operation

Manufacturer runtime

8hrs at 1/4 load

Operating volume

64dB at 1/4 load

Fuel tank

1.6 Gal

03 · Size & ownership

52 lbs

Unit weight

18.3" x 12.7" x 18.2"

Unit dimensions

Warranty
3-year warranty
Certifications
CETL · EPA
Availability
Available
04 · Controls & safety

Starting

Recoil

Power quality

3% THD

Safety

Low-oil shutdown · CO Alert

Electrical

120 · 60

1 × 5-20R 120V 20A SINGLE · 1 × L5-30R 120V 30A TWISTLOCK · 1 × USB C 5V 3A 9V 3A 12V 2.5A · 1 × USB A 5V 3A 9V 3A 12V 2.5A

Official product gallery

Product views and FIRMAN infographics.

These manufacturer images may include dimensions, control-panel callouts, included equipment, safety features, and common use cases. Scroll sideways to view the complete set available for this model.

FIRMAN WT03571 product view
Official FIRMAN gallery image 1 of 9
FIRMAN WT03571 official gallery image 2
Official FIRMAN gallery image 2 of 9
FIRMAN WT03571 official gallery image 3
Official FIRMAN gallery image 3 of 9
FIRMAN WT03571 official gallery image 4
Official FIRMAN gallery image 4 of 9
FIRMAN WT03571 official gallery image 5
Official FIRMAN gallery image 5 of 9
FIRMAN WT03571 official gallery image 6
Official FIRMAN gallery image 6 of 9
FIRMAN WT03571 official gallery image 7
Official FIRMAN gallery image 7 of 9
FIRMAN WT03571 official gallery image 8
Official FIRMAN gallery image 8 of 9
FIRMAN WT03571 official gallery image 9
Official FIRMAN gallery image 9 of 9

Complete specifications

Every official field, organized.

The technical fields below come from FIRMAN’s model-specific specification file. Product photos and infographics come from the official product gallery. Confirm current documentation before purchase.

Outdoor use only for combustion models. Never operate a fuel-burning generator inside a home, garage, shed, or other enclosed space. Follow FIRMAN’s manual and use an approved transfer method for home connections.

Manufacturer overview

The FIRMAN WT03571 Tri-Fuel Inverter Generator delivers 4,125 starting watts and 3,300 running watts of clean, stable power, making it ideal for RV use, camping, and home backup. With the flexibility to run on gasoline, propane, or natural gas, it adapts to your needs wherever you are. It is designed to ensure efficient, dependable operation for handling demanding appliances and sensitive electronics. Its compact 1.6-gallon fuel tank provides up to 8 hours of runtime at 50% load on gasoline, while its lightweight 52-pound design makes it easy to transport. Parallel capability allows you to connect a second unit for increased output, and it includes an L5-30P to TT-30R adapter for convenient RV connection. Built-in CO Alert adds an extra layer of security. Compact, flexible, and reliable, the FIRMAN WT03571 delivers powerful inverter performance wherever your next adventure—or emergency—takes you. The WT03571 comes with an LPG/NG Regulator, a 12V Battery Cable, an Adaptor L5-30P to TT-30R, Engine Oil, an Oil Funnel, and a Tool Kit

Specifications · Certifications

EPA Certified
Yes
cETL Certified
Yes

Specifications · Output

Starting Watts
4400(Gas) 4000(LPG) 3500 (NG)
Running Watts
3500(Gas) 3200 (LPG) 2800 (NG)
AC Voltage
120
DC Voltage
12
Frequency (Hertz)
60
Decibels
64dB at 1/4 load
Run Time
8hrs at 1/4 load
THD @ Full Load
3%

Specifications · Control Panel

Electric Start
Yes
Recoil Start
Yes
5-20R 120V 20A SINGLE
1
L5-30R 120V 30A TWISTLOCK
1
DC 8.3A 12V
1
USB C 5V 3A 9V 3A 12V 2.5A
1
USB A 5V 3A 9V 3A 12V 2.5A
1
Parallel Ports
1
CO Alert
Yes

Specifications · Machine

Low Oil Shutoff
Yes
Power Stream Alternator
Yes
Cast Iron Sleeve
Yes

Specifications · Fuel System

Fuel
Gas
Tank Size
1.6 Gal
Steel/Plastic
Plastic

Specifications · Wheel Kit

Handle
Fixed Handle

Packaging · Unit

UPC
840876135716
Unit Dimensions
18.3" x 12.7" x 18.2"
Unit Length
18.3"
Unit Width
12.7"
Unit Height
18.2"
Unit Weight
52 lbs

Packaging · Carton

Carton Dimensions
21.1" x 14.9" x 20.1"
Carton Length
21.1"
Carton Width
14.9"
Carton Height
20.1"
Carton Weight
62 lbs

Best-fit uses

  • Camping
  • Home Projects
  • Power Outage
  • Tailgate
  • Work

Standout features

  • Tri-fuel flexibility
  • Inverter power
  • CO Alert shutdown protection
  • Recoil start

Compare it with your actual load.

Run your essentials through our independent wattage calculator before buying.

Check my power plan
Official sources:FIRMAN product pageTechnical specificationsAll FIRMAN generatorsVerified September 15, 2026

Price & Availability

Compare the whole buying route.

The lowest sticker price is not always the best offer. We rank exact-model seller pages using price, stock, shipping, freshness, returns, and warranty details—then show what is still unknown.

Price and delivered cost

Shipping is included only when the seller publishes a usable amount.

Stock and freshness

Current, low-stock, preorder, and stale records are scored differently.

Purchase protections

Published return and warranty terms improve evidence confidence.

Affiliate-neutral ranking

Commission status is recorded but never adds ranking points.

Watch this model

Save it to your shortlist to retain the current price snapshot and turn price and safety watches on or off.

Best current buying route

FIRMAN WT03571

Review soon

Observed price

$1,130

at FIRMAN · Verify stock

Verify offer

Seller options

1

1 with price

Offer rank

57/100

Relative to listed sellers

Data confidence

55%

4 open fields

Delivered totals

0/1

Shipping included

The only verified seller destination. Its listed price is known, but shipping and delivered cost still need confirmation.

Seller data checked Sep 15, 2026.

Shipping not yet verified.

Open fields: confirmed stock, delivered cost, return window, warranty term.

Prices, local stock, shipping, taxes, installation, and seller terms can change. Confirm the exact model and final checkout total before buying. Affiliate disclosure.

Seller comparison

Every verified exact-model destination.

Browse all priced models

One exact-model seller destination is currently verified. We show the unknown fields so a single listing is never presented as a broad market comparison.

FIRMAN

Best overallLowest listed
Review soon

$1,130

Final total at checkout

Availability
Verify stock
Shipping
Shipping not yet verified
Returns
Not verified
Warranty
Not verified
Verify seller

55% data confidence · checked Sep 15, 2026

Price history

A durable record, starting with verified snapshots.

We preserve each dated seller observation instead of replacing the old number. Trends use the lowest verified listed price on each observation date—not an estimated market price.

FIRMAN

$1,130 · Verify stock

Verify offer

Ownership

What living with it looks like.

Ownership requires a safe fuel plan, hour-based engine service, correct storage, and confidence that parts and support are accessible.

Ownership rule

Use the exact FIRMAN WT03571 manual for maintenance intervals, fluids, storage limits, and warranty requirements. Similar models are not interchangeable.

Open owner’s manual Manufacturer support

Published warranty

3-year warranty

Coverage can vary by use, seller, and region. Confirm eligibility and exclusions before purchase.

Service information

2 official resources

An owner or operator manual is linked below for exact service intervals.

Routine upkeep

Engine service required

Oil, filters, spark plug, fuel system, and starting battery needs vary by model and hours used.

Handling & storage

52 lb · Gasoline + Propane + Natural gas

Store dry, fully cooled, and away from ignition sources; follow the manual’s fuel-storage procedure.

Practical care plan

From delivery to long-term readiness

  1. 1

    Day one

    Register and record the exact unit

    Save the receipt, serial number, seller, warranty terms, and model-specific manual before packaging is discarded.

  2. 2

    Before first load

    Complete setup and break-in correctly

    Add the specified oil, inspect the fuel system, position the generator outdoors, and follow the exact break-in and first-service instructions in the manual.

  3. 3

    Before every use

    Check the safety-critical basics

    Check oil level, leaks, cords, outlets, grounding instructions, CO-safe placement, and the transfer equipment needed for any building connection.

  4. 4

    By hours and season

    Log service and keep it outage-ready

    Track running hours and perform oil, filter, spark-plug, fuel-system, and starting-battery service at the intervals published for this exact model.

Before you buy

Five ownership questions to settle first

  • Confirm that 3-year warranty applies to your seller, region, and intended use.
  • Open the official manual for WT03571 and review setup, service intervals, warnings, and storage requirements.
  • Verify access to FIRMAN parts, authorized service, and a practical return path in your area.
  • Plan approved fuel storage, outdoor operating clearance, weather protection, and safe refueling.
  • Confirm the unit, fuel or charging gear, and essential cords fit the intended storage and transport space.
Manuals and compatible accessories Compare seller protections

Evidence

See the proof behind the conclusion.

We separate sourced facts, reproducible calculations, editorial judgments, and missing evidence. That makes every important claim easier to inspect—and harder to overstate.

Published-data coverage

100%documented

8 of 8 relevant evidence fields are documented for this model.

Source-backed editorial analysis—not a hands-on or laboratory test.

Read our evidence standard Explore original market research

Source record

3 traceable sources

Last reviewed Sep 15, 2026

Hands-on testing

Checking ledger…

No manufacturer data is presented as an independent test

Verified owners

Checking reports…

Percentages stay hidden until the sample qualifies

CPSC screening

No model-text match

39 generator recall records screened

100%

Documented fields

3

Traceable sources

4

Reproducible calculations

0

Open evidence gaps

Original calculation

Published surge reserve

900W

4,400W peak − 3,500W running

25.71% above rated running output. This is arithmetic headroom, not a promise that every motor load will start.

Original calculation

Rated power density

67.31 running W/lb

3,500W ÷ 52 lb

A catalog-derived portability ratio. It does not account for handles, wheels, shape, or how the weight feels in use.

Original calculation

Listed dollars per running kW

$322.85/kW

$1,129.99 ÷ 3.5 running kW

A point-in-time catalog value ratio. It excludes tax, shipping, accessories, fuel, service, and battery expansion costs.

Original calculation

Strongest class-relative spec

93th percentile

Product weight: 52 lb ranked within 177 mid output inverter generators

Lighter than 93% of its class

Claim-by-claim evidence ledger

Evidence typeClaimBasisTrace
Published factSource-backed3,500W running and 4,400W peak output are recorded for this model.Model-specific output fields in the catalog.Official model source
Published factSource-backedGasoline + Propane + Natural gas power and 52 lb product weight are recorded.Published configuration and dimensional data.Official model source
Original calculationReproduciblePublished surge reserve: 900W.4,400W peak − 3,500W runningCalculation standard
Original calculationReproducibleRated power density: 67.31 running W/lb.3,500W ÷ 52 lbCalculation standard
Original calculationReproducibleListed dollars per running kW: $322.85/kW.$1,129.99 ÷ 3.5 running kWCalculation standard
Editorial judgmentEditorialBest for specific needs for camping & home projects.Class score 49/100, declared best use, comparative specifications, and explicit buying cautions.Inspect the score
Editorial judgmentEditorialConfirm the outlet mix, transfer-equipment needs, runtime test load, and local service coverage before buying.Editorial risk check based on product category, weight, output, price availability, and missing fields.Judgment standard

What this evidence cannot prove

  • No Find My Generator hands-on test, instrumented load test, teardown, or long-term ownership trial is claimed for this page.
  • Manufacturer specifications may use different fuels, loads, test distances, temperatures, or operating modes. Cross-brand comparisons inherit those differences.
  • The listed price is a dated snapshot and may not equal the current delivered price.

Editorial analysis for FIRMAN WT03571. Source record last verified Sep 15, 2026. Corrections can be submitted through the contact page with a model-specific source.

Ownership resources

Accessories, manuals, and documents.

Start with the exact FIRMAN WT03571 model or item number. Accessory families can look alike while using different connectors, electrical limits, engines, or mounting points.

Compatible accessories

Match by model and connection.

Verify exact fit

Generator power cord or inlet connection

Use a correctly rated cord or professionally selected inlet connection for the intended load.

Match voltage, amperage, blade pattern, and wire rating to TT-30R. Home connections require approved transfer equipment and qualified installation.
View official accessory options
Verify exact fit

Parallel kit

This model’s published information references parallel operation. Use the manufacturer’s matching kit and pairing rules.

Confirm that the kit explicitly names WT03571 or its exact generator family before connecting another unit.
View official accessory options
Verify exact fit

Maintenance kit and service parts

Model-matched filters, spark plugs, batteries, oil supplies, and service parts support scheduled maintenance.

Match the complete WT03571 model or item number and follow the maintenance table in its manual.
View official accessory options
Verify exact fit

Storage cover or approved running shelter

A fitted storage cover protects a cooled, stored generator. A running shelter must be designed for generator operation.

Never run a fuel-burning generator indoors or inside a storage cover. Follow the manual’s clearance and ventilation requirements.
View official accessory options

Manuals & PDFs

Official product materials.

Specification sheetData fileManufacturer performance, electrical, dimensional, and equipment data.Manuals and document lookupSupport pageSearch FIRMAN support materials using the complete model, item, or serial number.

Compatibility note: Links lead to manufacturer or official retailer resources. Confirm the full model or item number, connector type, voltage, amperage, and published compatibility list before buying. Installation involving a home panel, inlet, transfer switch, or fuel plumbing should be handled as required by local code.

Deeper analysis

Open the details you need

The key decision is above. These supporting scorecards, owner signals, and evidence notes stay out of the way until you want to inspect them.

Fit and score detailsSee the class benchmarks and personalize the fit score for your needs.

Find My Generator score

49/ 100

Best for specific needs

Compared with 177 mid output inverter generators in the current catalog.

Power46

Running and peak output versus the class

Endurance23

Longest published runtime figure

Portability93

Lower weight scores higher

Quietness27

Lower published dBA scores higher

Fuel flexibility90

Multiple fuel choices

Value26

Output or stored energy per listed dollar

Class comparison

See what each spec really means.

A number is more useful with context. Each row shows this model beside its class median and translates the difference into a percentile.

Running output

Higher than 46% of its class

This model · 3,500W
Median · 3,500W

Peak output

Higher than 45% of its class

This model · 4,400W
Median · 4,500W

Published runtime

Longer than 23% of its class

This model · 8 hr
Median · 9 hr

Product weight

Lighter than 93% of its class

This model · 52 lb
Median · 91 lb

Published sound level

Quieter than 27% of its class

This model · 64 dBA
Median · 62 dBA

How the score works: Scores use published specs and are relative to comparable products in this catalog. Missing specs are excluded and remaining weights are normalized. Runtime is the longest manufacturer-published figure and may use a different load or fuel than another model.

Size a generator for your own appliances

Starter Fit Score

98/ 100

Excellent fit

For a 3,000W target and a $1,500 budget.

Clears your critical profile limits

Why it scored this way

A score you can inspect and change.

This personal score is separate from the model’s class score. It measures fit against your priorities and gives neutral partial credit when price or noise data is missing.

Power fit

35/35

Clears your 3,000W running target.

Budget fit

20/20

$1,129.99 is within your budget.

Fuel fit

15/15

Gasoline + Propane + Natural gas works with your flexible fuel preference.

Portability

10/10

52 lb against your medium portability priority.

Noise fit

8/10

64 dBA against your medium quietness priority.

Use-case fit

10/10

Home-backup fit rewards adequate output and fuel flexibility.

Tune my profile
Testing, reviews and evidenceCheck hands-on testing status, owner reliability signals, sources, and data confidence.
Checking the hands-on test ledger…

Testing protocol

The methods behind every result.

This category-specific protocol defines the questions, equipment, conditions, outputs, and safety gates required for this exact model. Published specifications stay visibly separate from hands-on measurements.

Open the hands-on test ledger Read the full test protocol Download measurement worksheet

Manufacturer-published baselines

Rated running output

3,500W

Published

Peak / starting output

4,400W

Published

Product weight

52 lb

Published

Published sound level

64 dBA

Published

These numbers organize the test plan. They are not independent confirmations.

Model-specific test matrix

Questions the measurements must answer.

01

Planned measurement

Continuous output & regulation

Pending

Can WT03571 hold useful loads without unacceptable voltage or frequency drift?

After manufacturer-specified warm-up, apply a correctly rated resistive load bank at 25%, 50%, 75%, and 100% of rated running output. Hold each step for a defined interval and continuously log watts, volts, frequency, and protective events.

Sustained wattsVoltage rangeFrequency rangeFaults or shutdowns
02

Planned measurement

Starting-load response

Pending

How much voltage and frequency sag occurs during a repeatable stepped starting load?

Use a controlled, instrumented starting-load fixture within published limits. Repeat the same step three times and record the lowest voltage, lowest frequency, recovery time, and whether protection trips.

Peak delivered wattsVoltage sagFrequency sagRecovery time
03

Planned measurement

Fuel use & runtime

Pending

How much usable energy is produced from a measured fuel quantity?

Outdoors at a controlled load, record the starting and ending fuel mass or volume using a safe approved method. Log elapsed time and delivered watt-hours without refueling during the valid measurement window.

Runtime at stated loadFuel per hourkWh per unit of fuelTest fuel and mode
04

Planned measurement

Sound profile

Pending

How loud is the unit under repeatable operating loads?

At an open outdoor site, measure A-weighted sound with a calibrated meter at 7 m / 23 ft on four sides at idle or eco, 25%, 50%, and 75% load. Publish distance, meter response, wind, surface, and ambient level.

dBA by side and loadAmbient dBADistanceOperating mode
05

Planned measurement

Cold & hot starting

Pending

How consistently does the unit start under documented conditions?

Follow the manual exactly and record three ambient-temperature starts plus three heat-soaked restarts. Report attempts, elapsed time, start method, battery state, and any intervention.

Attempts per startStart timeAmbient temperatureStart method

Controlled conditions

  • Record the exact model, serial number, firmware, sample source, and test date before any measurement.
  • Log ambient temperature, humidity, elevation, wind, surface, and background sound for every test block.
  • Record instrument model, range, accuracy, and most recent calibration or verification date.
  • Repeat timing, starting, and sound measurements three times when conditions allow; publish every valid run.
  • Keep original notes, load logs, meter exports, photos, and any excluded-run explanation with the result.

Required equipment class

  • Rated resistive or programmable load bank
  • True-RMS power, voltage, and frequency logger
  • Calibrated Class 1 or Class 2 sound-level meter
  • Approved fuel-measurement equipment and fire protection
  • Weather meter, timer, tachometer, and non-contact thermometer

Safety gate

Operate fuel-burning equipment outdoors only, far from occupied structures, openings, and ignition hazards, with working carbon-monoxide monitoring for personnel.

Testing is for qualified personnel using correctly rated load equipment and the manufacturer’s required grounding, bonding, clearance, and protective-device instructions.

Never connect a generator directly to building wiring or bypass overload, temperature, battery, GFCI, or carbon-monoxide shutdown protection.

Stop a run for unstable voltage or frequency, overheating, fuel or electrolyte leakage, abnormal sound, damaged wiring, or any manufacturer fault indication.

Badge rule: this product receives no “FMG Tested” label or score benefit until a real unit, instruments, conditions, valid runs, raw records, and limitations are documented under the public protocol.

Verified owner reliability

What happens after the honeymoon period?

Long-term reports from confirmed owners show starting, maintenance, failure, support, and recommendation outcomes for the FIRMAN WT03571.

See how ownership is verified

Verified owners only

Be the first confirmed owner to report back.

Checking reports…

Reliability percentages stay hidden until at least 5 ownership-verified reports are published for this exact model — 5 more needed.

Ownership checked

Purchase or registration evidence is reviewed privately.

Time in service

Reports separate new ownership from 12+ month experience.

Failures documented

Repairs and maintenance are captured, not buried in a star.

Reports stay private while ownership and model details are checked. Contact information is never shown publicly.

Data trust & safety

Fresh specifications. Visible recall checks.

We show when this record was verified, where its specifications came from, and whether its model number appears in the official CPSC generator-recall dataset.

Review soon

Specification freshness

Last verified
Sep 15, 2026
Review target
Oct 15, 2026
Primary source
Manufacturer / official listing

Prices can change faster than technical specifications. Always confirm the current price, exact model number, and manual before purchase.

CPSC model screening

No model-number match found

39 records checked
The FIRMAN WT03571 model text did not match the generator recall records in our current CPSC snapshot. This is a screening result, not a guarantee or safety certification. Recalls can be serial-number specific, newly published, or use a different product description.
Search CPSC directly Dataset checked Sep 16, 2026

Research owner

Founder & lead researcher

Editorial sign-off

Find My Generator Editorial Review

Accountable editor: Andrew Petla

Review scope: exact model identity, published specifications, calculation inputs, source quality, safety language, and affiliate independence. This is an internal editorial review, not third-party engineering, electrical, or safety certification. Hands-on testing is claimed only when a complete test record is published.Request a correction.
Read the full data methodology

Related actions

Keep the decision moving.

Compare the FIRMAN WT03571, test it against your actual power needs, or save it so price and specification changes are easier to revisit.

Not sure? Use the 60-sec finder
Best next step

Compare side by side

Open the comparison workbench with this exact model already selected, then add up to three alternatives.

Start comparison

Save and watch

Keep this model in your shortlist and surface tracked price, specification, and recall-match changes.

Check your power plan

Add the appliances and starting loads that matter, then compare the result with this model’s rated output.

Open calculator

Browse similar models

Return to the catalog with gasoline + propane + natural gas models filtered for a faster alternative search.

See alternatives

Recheck current offers

Review exact-model sellers, delivered-price visibility, stock, returns, warranties, and freshness before leaving the site.

Return to prices