Hoymiles HiFlow Pro
The first plug-in microinverter certified to UL3700, the Hoymiles HiFlow Pro is built strictly for the US market (120V/60Hz): not sold in the UK.
Characteristics
- Target market: US only, 120V/60Hz
- Output: 360 to 500 VA per unit, 4 in parallel for 1200W
- Certification: UL3700 (US standard), not valid in the UK
- UK alternative: Hoymiles HMS-800W-2T (230V), already in our catalogue
- First UL3700-certified microinverter, US only
Detailed overview: Hoymiles HiFlow Pro LV UL3700 plug-in microinverter
The Hoymiles HiFlow Pro is a plug-in solar microinverter announced in July 2026, presented by Hoymiles as the first microinverter certified to UL3700, the new US safety standard for plug-in solar equipment. This fiche exists for reference only: the product is designed exclusively for the US electrical grid (120V/60Hz) and is neither sold nor certified for a UK installation.
The HiFlow Pro LV line is modular: each compact unit (182 x 164 x 30mm, 1.8kg) connects a single solar panel through one MPPT tracker, rated from 360 to 500 VA depending on the panel paired with it. Up to four units can run in parallel on the same circuit for a combined 1200W, the ceiling used by most US state plug-in solar laws (Utah, Maine, Virginia, Maryland, Colorado, Connecticut, Vermont, New Hampshire). This state-by-state framework has no equivalent in the UK, where balcony solar follows different national rules and grid-connection requirements.
UL3700 covers exactly the risk a plug-in device raises: rapid shutdown, anti-islanding and touch safety for equipment that feeds power in through a wall outlet, requirements a general-purpose inverter standard does not address. Hoymiles pairs the certification with a NEMA Type 6 (IP67-equivalent) enclosure rated from -40 °C to +65 °C, and commissioning through Bluetooth and then WiFi in under a minute via the S-Miles Home app.
For a UK or wider European balcony system, the relevant product remains the Hoymiles HMS-800W-2T, a 230V/50Hz microinverter certified for the UK grid and already in our catalogue. Hoymiles sells the HiFlow Pro in the US through an authorised dealer network rather than direct checkout, backed by a 12-year warranty. The price shown here (£124.90) is an indicative same-day conversion of the US price of USD 169, for reference only: it is not a real price charged in the UK.
Full specifications
Detailed characteristics
Power and protection
| Output power?Maximum power delivered (for storages with a 230 V output). | 360 W |
|---|
Solar section
| MPPT controllers?Number of built-in MPPT solar controllers (lets you connect panels facing different directions). | 1 |
|---|---|
| Max solar input?Maximum connectable PV power. | 470 W |
| Micro-inverter?Power of the inverter that feeds energy back into the home grid. | 360 W |
Connectivity
| Bluetooth?Monitoring and settings via an app over Bluetooth. | Yes |
|---|---|
| Wi-Fi?Remote control and updates over Wi-Fi. | Yes |
Durability and format
| Ingress protection?Water and dust resistance (IP rating). | NEMA 6 / IP67 |
|---|---|
| Weight?Weight of the battery. | 1.8 kg |
| Dimensions (L × W × H)?Length × width × height, in millimetres. | 182 × 164 × 30 mm |
Availability and warranty
| Market launch?Date the model first became available on the European market. Useful to place its generation: technology moves fast in this segment, and a device several years old may be at the end of its commercial life. | July 2026 |
|---|---|
| Warranty?Length of the manufacturer's warranty. | 12 years |
Comparison
The HiFlow Pro compares most directly to the EcoFlow Stream Microinverter, its main rival in US plug-in solar. Neither product, however, is sold, certified or available in the UK: this table remains a technical reference only.
| Criterion | Hoymiles HiFlow Pro (per unit) | EcoFlow Stream Microinverter |
|---|---|---|
| Nominal output | 360 to 500W, 4 in parallel for 1200W | 1200W, single unit |
| Solar input | 1 MPPT per unit, one panel each | 3 MPPT, up to 1350W |
| Certification | UL3700 (first of its kind in the US) | UL1741 |
| Warranty | 12 years | Not stated by EcoFlow |
| Observed price (US) | ≈ USD 169 for one 360W unit | ≈ USD 369 |
Neither device is sold in the UK: this comparison is only a reference point for understanding the US plug-in microinverter market. For a UK installation, the Hoymiles HMS-800W-2T remains the sold and certified choice for the 230V grid.
Our tester's review: Julien De Jurquet
We followed the HiFlow Pro's launch with real curiosity: Hoymiles has built its reputation on being the reliable, unglamorous option, and watching the brand take on a brand-new standard (UL3700, published in December 2025) is genuinely interesting. On paper, the approach fits the brand well: rather than rebadge its European 230V balcony microinverter, Hoymiles designed a dedicated modular line for the US 120V grid, one unit per panel, stackable up to four deep. The real issue, for a UK reader, is that none of it applies to our grid: not the UL3700 certification, not the output voltage, not even the sales channel, an authorised US dealer network. This fiche is therefore a technical reference, not a buying recommendation: for a UK balcony system, the same brand's HMS-800W-2T, already reviewed by our team, remains the sensible choice.
Frequently asked questions: Hoymiles HiFlow Pro LV UL3700 plug-in microinverter
No. Hoymiles designs and sells this microinverter exclusively for the US market, through a network of authorised local dealers. No 230V version or European certification currently exists for this model.
It is the first US safety standard written specifically for plug-in solar equipment, published in December 2025. It covers rapid shutdown and anti-islanding for a device that feeds power in through a wall outlet, a framework with no direct UK equivalent.
One panel per HiFlow Pro unit, up to 470W or more depending on the exact model. Up to four units run in parallel for a combined 1200W, the ceiling set by US state plug-in solar laws.
Yes: the Hoymiles HMS-800W-2T, a 230V/50Hz microinverter certified for the UK and European grid, already in our catalogue, with 2 independent MPPT inputs and a 12-year warranty.
To give a complete picture of the global microinverter market and allow comparisons with models genuinely available in the UK, such as the same brand's HMS-800W-2T.
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Published on 08/09/2026