Geyserwise Megawatt Saver Geyser Controller
R 5 519,95
Price history
Around its usual price right now (R 5 519,95 typical).
Lowest R 5 519,95 · highest R 5 519,95 over 46 snapshots.
Tracked since 27 Aug 2026.
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<h3>Product Overview</h3>
<p>The Geyserwise MWS Controller is a solar PV water-heating controller designed to help convert a standard electric geyser into a PV-assisted hot water system. It uses MPPT technology to manage solar input from PV panels and supply controlled power to a compatible geyser element, reducing reliance on grid electricity for water heating where the system is correctly designed and installed.</p>
<h3>Key Features</h3>
<ul>
<li>MPPT solar control helps improve power conversion from the PV array to the geyser element.</li>
<li>Supports solar PV input with a maximum input voltage of 350 VDC and maximum solar array size of 4000 W.</li>
<li>Designed for use with geyser elements from 1500 W to 4000 W, with supported element resistance from 12Ω to 27Ω.</li>
<li>Can operate from solar PV or 230 V AC supply, allowing for practical solar water heating with mains backup.</li>
<li>RS485 communication between the display and main MWS box.</li>
<li>Wi-Fi support via Tuya or Smartlife applications for connected system control.</li>
<li>Includes reverse polarity protection for solar PV connections.</li>
<li>IP32 enclosure ingress protection rating for suitable protected installation environments.</li>
</ul>
<h3>Applications</h3>
<ul>
<li>PV-assisted water heating for domestic electric geysers.</li>
<li>Homes looking to reduce grid electricity usage for hot water heating.</li>
<li>Installations where a traditional pumped solar thermal system is less practical.</li>
<li>Solar geyser conversions where the geyser and PV array can be correctly matched to the MWS controller requirements.</li>
</ul>
<h3>Why Choose This Product?</h3>
<p>The Geyserwise MWS Controller is a practical option for homeowners and installers who want to use solar PV to heat water without adding a pumped thermal collector system. It is designed around PV input, MPPT conversion, geyser element control, and app-based connectivity, making it well suited to correctly specified South African solar water-heating installations.</p>
<h3>Important Notes</h3>
<ul>
<li>This product must be installed by suitably qualified persons, and an electrical COC is required.</li>
<li>The PV array must be designed so that the open-circuit voltage does not exceed the controller limit of 350 VDC.</li>
<li>The maximum solar panel current must be below 15 A.</li>
<li>The controller is not suitable for use with PTC elements.</li>
<li>PV panel selection, series configuration, geyser element resistance, irradiation level, roof structure, cable sizing, and safety requirements must be checked before installation.</li>
<li>Dimensions, weight, included accessories, and warranty terms for the controller were not specified on the reviewed source page and should be confirmed before publishing if required.</li>
</ul>
<h3>Technical Specifications</h3>
<table>
<tbody>
<tr>
<th>Specification</th>
<th>Detail</th>
</tr>
<tr>
<td>Brand</td>
<td>Geyserwise</td>
</tr>
<tr>
<td>Product Type</td>
<td>MWS solar PV water-heating controller</td>
</tr>
<tr>
<td>Maximum Input Voltage</td>
<td>350 VDC open-circuit voltage</td>
</tr>
<tr>
<td>Rated Input Voltage</td>
<td>230 V AC, 350 V DC</td>
</tr>
<tr>
<td>Rated Input Current</td>
<td>20 A AC, 15 A DC</td>
</tr>
<tr>
<td>Solar Input Voltage Range</td>
<td>125 VDC to 350 VDC</td>
</tr>
<tr>
<td>MPPT Range</td>
<td>120 V to 350 V DC</td>
</tr>
<tr>
<td>Maximum Input Current</td>
<td>15 A</td>
</tr>
<tr>
<td>Maximum Solar Power Conversion</td>
<td>4000 W</td>
</tr>
<tr>
<td>Maximum Solar Array Size</td>
<td>4000 W</td>
</tr>
<tr>
<td>Solar Connection</td>
<td>MC4 solar connectors</td>
</tr>
<tr>
<td>Solar Output Voltage</td>
<td>40 V to 230 Vrms modulated sine wave</td>
</tr>
<tr>
<td>Solar Output Current</td>
<td>20 A</td>
</tr>
<tr>
<td>AC Input</td>
<td>230 V AC, 50 Hz</td>
</tr>
<tr>
<td>Mains AC Voltage Range</td>
<td>85 V to 250 V AC</td>
</tr>
<tr>
<td>System Power Supply</td>
<td>Solar PV or 230 V AC</td>
</tr>
<tr>
<td>Compatible Geyser Element Power</td>
<td>1500 W to 4000 W</td>
</tr>
<tr>
<td>Element Resistance</td>
<td>12Ω to 27Ω</td>
</tr>
<tr>
<td>Element Compatibility</td>
<td>Not suitable for use with PTC elements</td>
</tr>
<tr>
<td>Thermostat</td>
<td>Electronic thermostat</td>
</tr>
<tr>
<td>Thermostat Safety</td>
<td>Electromechanical thermal cutout</td>
</tr>
<tr>
<td>Protection</td>
<td>Reverse polarity protection for solar PV connections</td>
</tr>
<tr>
<td>Ingress Protection Rating</td>
<td>IP32</td>
</tr>
<tr>
<td>Communications</td>
<td>RS485 between display and main MWS box; Wi-Fi via Tuya or Smartlife applications</td>
</tr>
<tr>
<td>Mounting</td>
<td>MWS to be mounted vertically</td>
</tr>
<tr>
<td>Standards / Approvals Listed By Source</td>
<td>EN / IEC 62109-1, IEC 60730-2-9, IEC 60730-1, EN / IEC 61000-6-3, EN 61000-3-12, EN / IEC 61000-3-11, EN / IEC 61000-6-1, ICASA Type Approval</td>
</tr>
</tbody>
</table>
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