FAQs

The model number reflects maximum (peak) power. The number that matters for what you can run continuously is the rated power. See 1.2 and 1.8. Runtime varies with load — see 1.11.

Start by listing the devices you want to run at the same time, then add up two numbers for each: its running watts (continuous draw) and its starting watts (the brief surge some devices need to start). Your generator needs enough rated power to cover the total running watts, plus enough maximum power headroom to cover the largest starting surge happening at the same time. We recommend leaving a safety margin (see 1.4). If you're not sure, our sizing guide and power expert can help you match a model.

Running watts (also called rated or continuous watts) is the power a device uses while operating normally. Starting watts (also called surge or peak watts) is the extra, brief burst of power that motor-driven devices — refrigerators, pumps, AC units, power tools — need for the first 1–3 seconds when they turn on. Starting watts can be several times the running watts. A generator has to handle both: rated power for the continuous load, and maximum power for the momentary surge.

It depends on your total load and your use case:

• S2500iS (1.9 kW rated / 2.5 kW max) — lightest essentials: a few small appliances, lights, phone/laptop charging, CPAP.
• S3200iS (2.6 kW rated / 3.2 kW max) — small home backup and RV essentials with a bit more headroom.
• S3600iS (3.0 kW rated / 3.6 kW max) — mid-range home backup, RV, and light tool use.
• S4000iS Open-Frame (3.2 kW rated / 4.0 kW max) — higher continuous output for jobsite and heavier mixed loads.
• S4500iS (3.6 kW rated / 4.5 kW max) — the most output in the lineup, for the largest supported loads and tougher starting surges.

Size to your rated power need first, then confirm the maximum power covers your biggest starting surge. When in doubt, size up one model for margin.

Don't plan to run a generator at 100% of its rated power continuously. Leave roughly 20–25% headroom so the unit runs cooler, quieter, and longer, and can absorb starting surges without tripping overload protection. For example, if your continuous load is around 2,400 W, choose a model with rated power comfortably above that rather than right at it.

Your power needs may exceed our current portable generator lineup. Consider reducing simultaneous loads, operating high-watt appliances one at a time, or contacting our power expert.

You can also consider paralleling two units for greater output (see 1.7).

Inverter generators (S2500iS / S3200iS / S3600iS / S4500iS) produce cleaner, more stable power (low harmonic distortion), run quieter, and are safer for sensitive electronics like laptops, phones, TVs, and CPAP machines. They're ideal for home backup, RV, and camping. The open-frame model (S4000iS) prioritizes higher continuous output and is well suited to jobsite and tool-heavy use where ruggedness and sustained power matter more than quiet operation. Choose inverter for sensitive electronics and low noise; choose open-frame for heavier continuous work loads.

Yes. SIOKIUU inverter generators support paralleling two units through a dedicated parallel kit to get more output. We recommend paralleling two identical models for the best compatibility and performance; in that case the usable continuous output is roughly 80% of the two units' combined rated power. Different models can also be paralleled, but this involves matching the parallel box to the combined current, so for a cross-model combination please contact our technical support before ordering and we'll confirm the right setup and expected output for your needs.

Yes, as long as their combined running watts stay within the model's rated power and there's enough maximum power headroom for the largest starting surge that occurs at the same time. This is why you can't simply add up nameplate wattages and assume it fits — starting surges and simultaneous loads matter. Build a load list (see 2.7) and stage high-draw devices so they don't all start at once.

Because a generator can fail you in two different ways. If total running watts exceed rated power, it overloads during continuous use. If a starting surge exceeds maximum power, it can trip the moment a motor kicks in — even if the running load looked fine. Checking both is the only way to know a model will actually carry your equipment.

Yes — with an inverter model. The S2500iS, S3200iS, S3600iS, and S4500iS are inverter generators, which produce clean, stable power with low harmonic distortion. That's appropriate for sensitive electronics such as laptops, phones, TVs, CPAP machines, battery chargers, and equipment with electronic control boards.

The S4000iS is our open-frame model, built for higher continuous output on the jobsite. It runs tools, lights, and motors well, but its power isn't as clean, so for sensitive electronics choose one of the inverter models.

Whichever you choose, still size for the load: confirm your total running watts fit within the model's rated power, with headroom for any starting surge (see 1.1 and 1.4).

It depends on how much power you're drawing — the lighter the load, the longer a tank lasts. Our inverter models adjust engine speed to the load, which helps efficiency when you're running less. Here's what to expect at a quarter load:

Run closer to the rated output and the tank drains faster — at half load, expect roughly half those figures. For continuous operation, don't exceed the rated output, and plan your load with headroom (see 1.4). When you do need to refuel, shut the engine off and let it cool completely first (see 5.5).

Yes — these essentials are exactly what the lineup is built for. A refrigerator has a starting surge, so account for that in your sizing, but its running watts are modest. Lights, routers, TVs, and laptops draw relatively little. For CPAP, our inverter models produce clean, stable power that's appropriate for it. Add up the running watts of everything you want on at once and confirm it fits within your model's rated power, with headroom for the fridge's start.

It can run these, but treat them as high-draw devices and generally not all at the same time. A sump pump has a significant starting surge; microwaves and coffee makers pull heavy continuous watts while running. Depending on your model and what else is on, you may need to run these one at a time. Check each device's running and starting watts against your model's rated and maximum power.

Because nameplate/running watts ignore starting surges and assume everything runs at once. Motor-driven devices briefly draw several times their running watts at startup, and if two of them start together the combined surge can trip the generator even though the steady-state total looked safe. Size for both the continuous total (rated power) and the worst-case simultaneous surge (maximum power).

Prioritize health, safety, and food preservation first: medical devices (e.g., CPAP), refrigerator/freezer, essential lighting, and communications (phone charging, Wi-Fi router). Add comfort and convenience loads only if you still have rated-power headroom after the essentials.

Staging high-draw devices keeps you within your generator's limits and avoids overload trips. If several motor-driven appliances start at the same moment, their combined starting surge can exceed maximum power. By running them one at a time — or letting one finish its startup before the next begins — you stay safely inside the unit's capacity and get more stable performance.

No — and we won't claim it can. The current 2500W–4500W lineup is designed for essential home backup: keeping critical devices running during an outage, not powering an entire home's simultaneous loads (central AC, electric heating, well pumps, whole-home circuits). If you need whole-house power, that's beyond this lineup — reduce simultaneous loads, run high-watt items one at a time, or contact our power expert.

• List every device you'd want during an outage.
• For each, note its running watts and starting watts (check the label or manual).
• Mark which ones truly need to run at the same time.
• Add the running watts of that simultaneous set — this must fit within your model's rated power.
• Identify the single largest starting surge in that set — your model's maximum power must cover it on top of the running load.
• Leave 20–25% headroom (see 1.4). If it doesn't fit, stage devices or size up.

It depends on what you run. For RV essentials — lights, water pump, fridge, charging, small appliances — a mid-lineup model is often enough. If you want to run an air conditioner, you'll need to account for its large starting surge (see 3.2). List your simultaneous RV loads, total the running watts against a model's rated power, and confirm maximum power covers the biggest surge.

Selected RV air conditioners may be supported depending on their running watts, compressor starting watts, elevation, temperature, and other loads operating at the same time.

RV AC units have a large compressor starting surge, so whether a given unit is supported depends on the factors above. Check your AC's running and starting watts against the model's rated and maximum power, and avoid running other heavy loads at the same moment the compressor starts.

Yes — our inverter models (S2500iS / S3200iS / S3600iS / S4500iS) produce clean, stable power with low harmonic distortion, which is appropriate for sensitive RV electronics like TVs, laptops, and control boards. For sensitive electronics, an inverter model is the right choice.

"RV-ready" generally means the generator can supply the type of power and connection an RV setup expects for its essential loads. In practice, what matters most is matching the generator's rated and maximum power to your RV's actual loads and ensuring clean inverter power for sensitive electronics. Confirm your specific loads against the model specs rather than relying on the label alone.

Usually not at the same time. Both are high-draw, and the AC's compressor surge plus a running microwave can exceed the generator's limits. Run them one at a time — for example, pause the microwave use while the AC compressor cycles — to stay within rated and maximum power.

Keep it outside and well away from the RV, never inside any compartment (including the generator compartment). The manual requires at least 1 meter (about 3 ft) minimum clearance, but to keep carbon monoxide away from sleeping and living space, follow the safer CDC/CPSC guidance of at least 20 feet (about 6 m), with exhaust pointed away from the RV, windows, vents, and neighbors. Never run a generator inside or under an RV. (See Section 5.)

Our inverter models are designed to run relatively quietly, which makes them better suited to campgrounds than open-frame units. That said, quiet-hour rules vary by campground, and even a quiet generator makes some noise — always check and follow the specific campground's rules on generator use and hours.

Transport and store gasoline only in approved fuel containers, away from heat, sparks, and open flame. When transporting the generator, follow the manual's guidance on the fuel tank cap/valve position to prevent leaks, and for longer transport or storage, drain fuel as directed. Never smoke or allow flames near fuel, and never refuel a hot or running engine (see 5.7).

Yes — these are typical loads for the lineup. Drills, sanders, work lights, and battery chargers are manageable; a circular saw draws more and has a starting surge. Check each tool's running and starting watts against your model's rated and maximum power, especially for saws and other motor tools.

Yes. The lineup — particularly the higher-output S4000iS Open-Frame and S4500iS — is well suited to small mobile repair, remodeling, and contractor work where you're running hand tools, lights, and chargers. Match the model's rated power to your typical simultaneous tool load.

Sometimes — it depends on the tools and the model. Combined running watts must stay within rated power, and there must be enough maximum power headroom for the largest tool's starting surge. In practice, running two motor tools at full load simultaneously is often too much; stage them so they don't start together.

Motors draw a brief, high starting surge — often several times their running watts — to overcome inertia when they spin up. That's why a saw or compressor rated at modest running watts can still trip a generator at the instant it starts. Your model's maximum power must cover that surge on top of any other running load.

An undersized or overly long cord causes voltage drop and heat, which reduces the power actually reaching your tool and can cause poor performance or nuisance trips. Use a heavy-duty outdoor-rated cord — the manual specifies a minimum of 14 AWG for up to 20 ft, dedicated to power-supply use. For longer runs, use a heavier gauge. (See 5.6.)

Yes — the inverter models deliver clean, stable power (low harmonic distortion) that's appropriate for chargers and sensitive electronic tools. If you're charging battery packs or running electronics on site, an inverter model is the safer choice over open-frame.

The current 2500W–4500W lineup is not intended for large welders, large industrial air compressors, or running multiple heavy-duty tools continuously at the same time. If your work requires that level of sustained power, consider reducing simultaneous loads, operating high-watt appliances one at a time, or contacting our power expert.

No — never. A running generator produces carbon monoxide (CO), a colorless, odorless, poisonous gas that causes nausea, dizziness, fainting, or death. Never operate it inside any building, including garages, basements, crawlspaces, sheds, tents, or any enclosure or compartment — including an RV's generator compartment. Never let exhaust enter an enclosed area through windows, doors, vents, or openings.

The manual requires at least 1 meter (about 3 ft) minimum operating clearance from buildings and equipment. To reduce carbon monoxide risk, U.S. safety agencies (CDC / CPSC) recommend placing it at least 20 feet (about 6 m) away from occupied space. Follow the more conservative 20-foot guidance when in doubt.

Always direct the exhaust away from buildings and people — away from windows, doors, vents, and anywhere air can carry fumes into occupied space. The generator must always be used outdoors, well away from occupied buildings.

Yes. Install and regularly test battery-powered CO alarms in any occupied building. Note that every SIOKIUU generator in the lineup also has a built-in CO Detection and Auto-Shutoff System that shuts the engine off if it senses dangerous CO levels (flashing red = danger, ventilate and leave; flashing yellow = sensor may need service; a 10-second blink at startup is a normal self-check). This built-in system is an added layer of protection — it does not make indoor use safe.

Stop the engine and let it cool completely before adding fuel. Gasoline is flammable and explosive — no smoking, sparks, or flames nearby. Don't overfill (leave no fuel on the filler neck), and wipe up spills before restarting.

No. Never feed power back into your home's wiring through a regular outlet. Backfeeding can electrocute utility workers, damage equipment, and cause fires. It's also why you must never use a homemade male-to-male ("suicide") cord (see 5.8).

Only through a proper transfer switch or interlock device installed by a qualified electrician. This safely isolates your home from the utility line. Do not attempt to connect the generator to household circuits any other way.

Because it energizes exposed prongs and your home wiring without isolation — a serious electrocution and fire hazard for you and for utility workers. There is no safe way to use one. Use a proper transfer switch instead (see 5.7).

Avoid wet operation where possible. Using a generator in rain, snow, near water, or with wet hands risks electrocution — keep the unit dry and on a dry, level surface. If it's been stored outdoors and exposed to weather, inspect all control-panel electrical components before each use, since moisture or ice can cause a short circuit.

Before first start, add the correct engine oil and gasoline as specified in your model's manual — new units do not ship filled. On a first start (or after long storage with the fuel used up), turn the engine switch to "ON" for 10–20 seconds first so fuel can reach the carburetor, then start. Always do a pre-operation check before starting.

Check in this order: (1) fuel — is there enough, and is the fuel valve/tank cap in the correct position; (2) engine switch and any fuel/choke controls set correctly; (3) oil level — a low-oil sensor can prevent starting (see 6.7); (4) spark plug and air filter condition; (5) for first use or post-storage, prime per 6.1. Pull the recoil cord correctly — slowly until you feel resistance, then a firm pull. If it still won't start, contact support (6.10).

Common causes: low oil triggering the protection shutoff (see 6.7), a fuel delivery problem (stale fuel, clogged line/carburetor after storage), a choke left in the wrong position after warm-up, or the unit not being level. Also confirm you're not starting with a device already plugged in and switched on. If it keeps stalling after these checks, contact support.

First confirm nothing has tripped: check the overload protection and reset if needed (see 6.6). Verify your device is properly connected and that you're using the correct outlet. Confirm the load is within the model's capacity. If the engine runs normally but no outlet produces power after these checks, stop and contact support — don't keep forcing it.

That's normal. As you add electrical load, the engine works harder and its speed and sound adjust to match demand — inverter models vary engine speed with load, so you'll hear it rise and fall. A change in tone when a device kicks on is expected. What's not normal is repeated overload trips or the CO/fault warnings — address those per the relevant question.

Reduce the load: turn off or unplug some devices so your total is back within the model's rated power (and staged so surges don't overlap). Then reset the overload protection per your manual. If it trips again, you're asking for more power than the unit can supply — remove more load, stage high-draw devices, or consider a larger model or paralleling (see 1.7). Note: the reset won't restore output unless the unit is actually out of the overload condition.

The low-oil sensor shuts the engine down to protect it. Move the generator to level ground, check the oil, and add the correct oil to the proper level as specified in your manual. Once oil is at the right level, you can restart. If the warning persists despite correct oil level, stop and contact support.

Because those sensors — CO auto-shutoff, low-oil protection, overload protection — exist to protect your life and your equipment. Bypassing them removes that protection, creates a real risk of CO poisoning or engine damage, and voids your warranty. If a sensor is tripping, the correct fix is to address the underlying cause (ventilation, oil level, load), not to defeat the sensor. If you believe a sensor is faulty, contact support (see 5.4 for the CO "sensor may need service" indicator).

After long storage, stale fuel and a dry carburetor are the usual culprits. Use fresh fuel, prime per 6.1 (engine switch "ON" 10–20 seconds so fuel reaches the carburetor), and check the oil level. If it was stored improperly (fuel left in for a long time), the carburetor/fuel system may need cleaning — see Section 7 on storage, and contact support if it still won't start.

Stop and contact support immediately if you notice: a fuel or oil leak, a burning smell, repeated CO or fault warnings, abnormal electrical output, or if the unit was dropped or physically damaged. Do not attempt internal repairs yourself — it can be dangerous and may void the warranty.

Follow the specific interval in your model's manual — the first (break-in) oil change is earlier than the routine interval that follows. Always use the oil type specified in your manual (e.g., SE 10W-30) and don't mix different oil specifications. Because intervals vary by model, treat the printed manual as the authority.

Old fuel is the most common cause of hard starting after storage. For storage longer than the manual's threshold, drain the fuel (tank and carburetor) as directed, or use appropriate fresh fuel and follow the manual's storage steps. Store gasoline only in approved containers, away from heat and flame.

Keep fuel fresh, and drain the system before long storage to prevent gum and varnish buildup in the carburetor. If the unit has sat with old fuel and now runs poorly or won't start, the carburetor/fuel system may need cleaning — follow your manual, and contact support if you're unsure.

Inspect and service the air filter and spark plug at the intervals in your manual, and keep the fuel system clean. The spark arrestor should be maintained on the schedule the manual gives (e.g., periodic maintenance tied to engine hours). Clean components help the engine start reliably and run efficiently.

Follow your manual's storage procedure, which generally includes: draining fuel from the tank and carburetor, changing the oil, treating the cylinder with a little oil and gently turning the engine to distribute it (leaving intake/exhaust valves closed to resist internal corrosion), and storing the unit on level, clean, dry ground in a low-humidity, low-dust area.

For any model with a starting battery, follow the manual's battery-care guidance and keep it charged during periods of non-use. Note that starting batteries are consumable accessory parts and are not covered by the warranty (see 8 / warranty exclusions).

Environmental conditions affect performance: high altitude, very cold, and very hot conditions can change starting behavior and available output, and cold weather affects fuel and oil. Follow your manual's guidance for operating in these conditions (including correct oil and any cold-weather steps), and factor conditions into your sizing — for example, RV AC support depends partly on elevation and temperature (see 3.2).

Before transport, set the fuel tank cap/valve and engine switch to the correct (OFF) position as the manual specifies, keep the unit upright and level, and avoid rough handling. For longer transport, drain fuel and oil beforehand as directed. Tilting the unit can cause gasoline to overflow.

Orders are processed and shipped within 2 business days.

We ship within the 48 contiguous U.S. states only. We do not ship to Alaska, Hawaii, Puerto Rico, Guam, the U.S. Virgin Islands, any other U.S. territories, APO/FPO military addresses, or PO Box addresses.

Contact us within 3 days of delivery with your order number and clear photos of the packaging and the damage. We'll make it right.

Let us know within 3 days of delivery with your order number and a photo of what you received. We'll get the missing items to you.

A 3-year limited warranty (parts and labor) from the date of original purchase. For commercial or industrial use, the period is 270 days (parts and labor). As long as the product was purchased from us and is within the warranty period, we honor the warranty.

Covered: defects in materials and workmanship in mechanical and electrical components.

Not covered:

• Normal wear and tear, and normal maintenance
• Damage from misuse, neglect, accident, abuse, modification, improper installation, or operating beyond the product's limits
• Cosmetic items (paint, decals)
• Wear parts (filter elements, O-rings)
• Accessory parts (starting batteries, storage covers)
• Failures caused by non-genuine SIOKIUU parts
• Acts of God / force majeure
• Use as a replacement for the utility's main power supply

Repairs/replacements done without prior authorization or at an unauthorized facility are not covered. A replacement unit is covered for the remainder of the original unit's warranty period.

You can return your generator within 30 days of delivery — no questions asked.

For a change-of-mind return, the customer covers return shipping and the item must be returned in its original packaging and in resalable condition. There is no restocking fee. If the issue is caused by the product (a defect or fault on our side), SIOKIUU covers the related costs, including return shipping and replacement or refund — you shouldn't be out of pocket for a problem that's our fault.

Please provide:

• Your order number
• The model (e.g., S3200iS) and, if available, the serial number
• A clear description of the issue
• Photos, and for issues like unusual noise, starting problems, or no power output, a short video if possible

We provide timely, responsive support and aim to get back to you as quickly as possible.

After you contact us with the details in 8.9, our support team reviews the issue: many problems are resolved with guidance or a part. If it's a covered defect, we'll arrange repair, replacement, or refund as appropriate to the situation — and for product-related faults, we cover the associated costs (see 8.8).