SMRT-HOT-WTR-30-S2 SolarEdge 3 kW Hot Water Controller Smart Immersion Optimiser Solar PV Diversion
SolarEdge 3kW Home Hot Water Controller (SMRT-HOT-WTR-30-S2) — Intelligent PV surplus diversion device for 3 kW immersion heaters | Maximises self-consumption of solar energy | Diverts excess solar power to heat water instead of exporting to grid | No additional inverter needed | Works with any SolarEdge system (single-phase) | App monitoring & control via mySolarEdge | IP65 rated for indoor/outdoor install | Boosts savings & reduces bills
✅ Turns wasted solar export into free hot water – perfect for homes with PV & immersion heaters
Ideal when your SolarEdge PV system generates more power than your home uses. Automatically diverts surplus to your 3 kW immersion heater instead of sending it to the grid for pennies. No separate energy diverter required — integrates seamlessly with your existing SolarEdge inverter & monitoring.
The SolarEdge Home Hot Water Controller (SMRT-HOT-WTR-30-S2) is a smart, single-phase PV surplus diversion device designed specifically to work with 3 kW immersion heaters. It intelligently monitors your SolarEdge PV production and home consumption in real time, then automatically diverts any excess solar generation directly to your hot water cylinder — turning “wasted” exported energy into free hot water.
Unlike traditional immersion diverters, this unit integrates natively with the SolarEdge ecosystem — no extra CT clamps, no separate hub, no complicated wiring. It uses the existing SolarEdge inverter communication and mySolarEdge app to show diversion performance, energy saved, and hot water contribution. The result is higher self-consumption, lower electricity bills, and faster payback on your solar investment — especially valuable with rising export tariffs and smart export guarantees (SEG).
IP65-rated for indoor or outdoor installation, compact design, and simple wiring (connects between inverter/CT and immersion heater). Fully compliant with UK regulations and compatible with all current SolarEdge single-phase inverters (HD-Wave & SE models). No need for a second inverter or battery — just smarter use of the solar you already generate.
What Makes the SolarEdge 3kW Hot Water Controller Special?
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Native SolarEdge Integration — Works directly with your existing SolarEdge inverter & mySolarEdge app — no third-party hardware or extra monitoring needed.
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Zero Export Diversion — Automatically diverts 100% of surplus solar to the immersion — maximises self-use & eliminates low export payments.
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Smart & App-Controlled — Real-time visibility of diverted energy, hot water contribution & savings via mySolarEdge app (iOS/Android).
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Boosts Self-Consumption — Can increase self-use by 20–40% in typical UK homes with immersion heaters — faster ROI on PV system.
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IP65 Weatherproof — Indoor or outdoor mount — flexible placement near cylinder or inverter.
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No Battery Needed — Uses existing solar surplus — cost-effective alternative or complement to battery storage.
Key Features
3 kW DiversionPrecisely controls 3 kW immersion heaters — matches most UK domestic cylinders.
Surplus DetectionReal-time monitoring of PV production vs home use — diverts excess only.
mySolarEdge AppView diverted kWh, savings & performance alongside your PV data.
Easy IntegrationConnects to SolarEdge inverter/CT — no additional sensors or hubs required.
IP65 RatedIndoor/outdoor install — robust & weatherproof enclosure.
UK Grid CompliantWorks with SEG & smart export — no G98/G99 issues for diversion.
Technical Specifications
| Specification |
Value |
| MPN / Part Number |
SMRT-HOT-WTR-30-S2 |
| Brand |
SolarEdge |
| Rated Power |
3 kW (single-phase immersion control) |
| Supply Voltage |
230 V AC ±10%, 50 Hz |
| Max Switching Current |
13 A resistive |
| Control Method |
Proportional diversion via SolarEdge inverter data |
| Compatibility |
SolarEdge single-phase inverters (HD-Wave & SE series) |
| Monitoring |
mySolarEdge app & portal (real-time diversion stats) |
| Protection Rating |
IP65 (indoor/outdoor) |
| Operating Temperature |
-20 °C to +60 °C |
| Dimensions (H × W × D) |
Approx. 200 × 150 × 80 mm |
| Weight |
Approx. 1.5 kg |
| Compliance |
UK Grid Code, G98/G99, CE, UKCA |
What's in the Box
✔ 1 × SolarEdge Home Hot Water Controller (SMRT-HOT-WTR-30-S2)
✔ Mounting bracket & fixings
✔ Wiring terminals & cable glands
✔ Installation & commissioning manual
✅ Requires existing SolarEdge single-phase PV inverter & mySolarEdge monitoring. Connects between inverter/CT and 3 kW immersion heater. Installation by qualified electrician per Part P & SolarEdge guidelines. Ideal for homes with unvented cylinders or Economy 7 immersion backup.
Frequently Asked Questions
Do I need a separate energy diverter or hub? No — the SMRT-HOT-WTR-30-S2 integrates directly with your SolarEdge inverter and mySolarEdge app — no extra hardware required.
Will it work if I export to the grid? Yes — it prioritises diversion to hot water before exporting. You still earn SEG payments on any remaining surplus after diversion.
Can I control it manually or set priorities? Yes — via the mySolarEdge app you can monitor performance, view diverted energy, and adjust settings (e.g. minimum diversion threshold or timer boosts).
Is it compatible with my immersion heater? Yes — designed for standard 3 kW single-phase immersion heaters (most UK domestic cylinders). Not suitable for 1 kW or 2 kW elements.
Does it work during power cuts? No — like most smart devices it requires mains power to operate. However, your PV inverter may continue in limited mode if battery-backed.
Can I install it outdoors? Yes — IP65 rated enclosure allows indoor or outdoor mounting (avoid direct sunlight if possible for longevity).
Who installs it? A qualified electrician (Part P registered recommended) — wiring must comply with BS 7671 and SolarEdge installation guidelines.
How much can I save? Many UK homes divert 1,000–2,500 kWh/year to hot water — at current rates that’s £150–£500+ annual saving vs exporting at low SEG rates.
