Madimack 300L (MMESGHW-300)
Rebates up to
$680
STC $680
Replace-electric, medium household, best zone. Enter your postcode below for exact figures.
VIC Solar Homes rebate
$1,000
50% of installed price, point-of-sale. Stacks with STC/VEEC above.
VIC only. Assumed eligible, not confirmed against the live Solar Victoria product list.
Register data as at CER (STC) 2026-04-30
Specifications
| Type | Integral all-in-one |
| Refrigerant | R290 |
| Tank volume | 300 L |
| Rated heating capacity | 2.775 kW |
| Rated power input | 0.664 kW |
| COP | 4.183 (Air 20 degrees C / water 15 degrees C) |
| Sound level | 48 dB(A) |
| Hot water delivery | 75 °C |
| Operating ambient | -7 to 43 °C |
| Tank height | 1890 mm |
| Tank diameter | 620 mm |
| Tank weight (empty) | 130 kg |
| Electric backup | 2 kW |
| Warranty | Tank 5, compressor 3, sealed system 5 |
Specs from: Madimack AU ResiSTEAM product page; 1stchoicehotwater.com.au listing; public STC register.
Certificate rebate by postcode
Registered certificate values
Every scheme this model is registered for, by zone. STCs at $40, VEECs at $85, ESCs at $30 (reference prices as at 2026-07-07). Claim year 2026, medium household.
SRES — STCs (national)
| Zone 1 | 13 STCs | $520 |
| Zone 2 | 13 STCs | $520 |
| Sydney (Z3) | 15 STCs | $600 |
| Melbourne (Z4) | 17 STCs | $680 |
| Canberra (Z5) | 16 STCs | $640 |
VEU — VEECs (Victoria)
Not yet registered for VEECs.
ESS — ESCs (NSW)
Not yet registered for ESCs.
Certificate counts are computed from the model's registered performance data using the current regulated equations. A lodged claim depends on the specific installation, household size, and the scheme rules in force at creation. Energy savings % is against the AS/NZS 4234:2021 reference electric storage water heater for that zone, medium household, calculated from the model's registered performance data.
The Madimack MMESGHW-300 (ResiSTEAM 300L) is an all-in-one air-source heat pump water heater: a single outdoor cabinet housing a 300 L tank with an R290 refrigerant circuit heating the water directly. Rated heating capacity is 2.775 kW at a 20 degrees C air / 15 degrees C water test condition, giving a declared COP of 4.183, and the unit operates across an ambient range of -7 to 43 degrees C.
The tank includes a 2.0 kW electric backup element for cold-ambient or high-demand periods, and delivers water up to 75 degrees C. Sound output is rated at 48 dB(A). The cabinet stands 1890 mm tall with a 620 mm diameter, weighing 130 kg empty.
Madimack’s warranty covers the tank for 5 years, the compressor for 3 years, and the sealed refrigerant system for 5 years.
Registered model codes
MMESGHW-300
Homeowners
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