5 star Geysers are generally the power saving storage water heater available in India. The star ratings of water heater geyser is dependent on standing loss of water geyser. Which means the amount of heat lost by storage water heater. So the star rating is more dependent on how long it can store the water hot in the inner tank of storage water. So insulation plays a bigger role in deciding the star ratings. So if you are a person who don’t let the hot water store inside for long or mostly use it immediately then this star rating will play a marginal role in your water power savings.

You should use higher energy star rated water geyser for bigger tank capacity storage geyser. Like for 25liters a 5 star rated is a must. For 10-15liters you can decide between 4-5star depending on price. For 6-10liters 3-4star is enough. It all depends on how long you keep hot water and how hot you set the water geyser temperature to.

Crompton Arno Neo 10-L 5 Star Rated Storage Water Heater with Advanced 3 Level Safety (White)
  • PRODUCT: Crompton’s energy efficient storage water heater with fast heating
  • TECHNICAL SPECIFICATIONS: Wattage: 2000 W; Capacity: 10L; Star Rating 5; Pressure 8 bar
  • 3 LEVEL SAFETY: Capillary Thermostat, automatic thermal cut-out & multi-functional valve to provide higher safety
  • ANTI-RUST: Fitted with specially designed magnesium anode which prevents corrosion due to hard water quality
Crompton Amica 15-L 5 Star Rated Storage Water Heater (Geyser) with Free Installation and Connection Pipes (White)
  • PRODUCT: Crompton’s energy efficient storage water heater with fast heating
  • TECHNICAL SPECIFICATIONS: Wattage: 2000 W; Capacity: 15L; Star Rating 5; Pressure 8 bar
  • 3 LEVEL SAFETY: Capillary Thermostat, automatic thermal cut-out & multi-functional valve to provide higher safety
  • ANTI-RUST: Fitted with specially designed magnesium anode which prevents corrosion due to hard water quality
  • QUALITY COMPONENTS: ISI marked nickel coated special element to provide resistance against scale formation
Candes Geyser 25 Litre | 1 Year Warranty | Water Heater for Home, Water Geyser, Water Heater, Electric Geyser, 5 Star Rated Automatic Storage Vertical Water Heater, 2000W – Perfecto (Ivory),Wall
  • Included Components: Geyser
  • Material Type: Stainless_Steel
  • Color: Ivory
  • Number of Pieces: 1
  • Special Feature: Auto Restart; Fast Heating
V-Guard Divino 5 Star Rated 15 Litre Storage Water Heater (Geyser) with Advanced 4 Level Safety, White,Wall
  • 【15 LITRE】Storage Water Heater; 【BEE 5 STAR RATED】: Highly Energy Efficient with Extra Thick & High Density CFC Free PUF Insulation for Maximum Heat Retention;【COUNTRY OF ORIGIN】: India
  • 【ANTI-CORROSIVE & SUITABLE FOR HARD WATER USAGE】: Advanced Vitreous Enamel Coating protects the Inner Tank, Superior Incoloy 800 Heating Element ensures Sustained Performance, Extra Thick Magnesium Anode provides Added Protection 
  • 【66% REDUCTION IN LEAKAGE】: Single Weld Line High Grade Mild Steel Tank
  • 【SAFETY ASSURED】: Advanced Thermostat & Thermal Cut-out Mechanism for Dual Overheat Protection; 5-in-1 Multi-function Safety Valve prevents excessive Pressure Build-up, Vacuum Formation & Reverse Water Flow
  • 【HYGIENIC & PUNGENT-FREE WATER】: Multi-layer protection against Corrosion & Scaling
AO Smith HSE-SHS-015 Storage 15 Litre Vertical Water Heater (Geyser) ABS Body BEE 5 Star Superior Energy Efficiency|Enhanced Durability Blue Diamond Glass Lined Tank |Suitable High Rise Buildings
  • Type : Storage ; Capacity 15 Liters, Wattage 2000 Watts; Pressure : 8 bars Factory set thermostat – Max 75C Double Protection with Thermal Cut-Out and Multi-function Safety Valve
  • Outer Body – ABS Plastic – superior glossiness and surface finish. Inner Tank Material: Blue Diamond Glass Lined Tank- 2X Corrosion Resistance
  • Warranty: 5 years on inner tank, 2 years warranty on glass coated heating element and 2 years comprehensive
  • BEE 5 Star rated for Maximum energy savings
Bajaj New Shakti Neo 25L Vertical Storage Water Heater|Star Rated Geyser|Heating with Titanium Armour & Swirl Flow Technology|Glasslined Tank| Wall Mounting|1-Yr Warranty by Bajaj|White
  • TYPE: Storage Water Heater/Water Geyser, Capacity: 25 Litres, Wattage: 2000 Watts. The rated voltage is 230 volts, and the frequency is 50 Hz.
  • WARRANTY: PRODUCT WARRANTY By Bajaj – 1 year. Tank Warranty by Bajaj – 5 years. Heating Element Warranty by Bajaj – 2 years.
  • BUILD TO LAST with GLASSLINE INNER TANK, TITANIUM ARMOUR TECHNOLOGY & MAGNESIUM ANODE for zero erosion: These technologies prevent corrosion & rusting of the geyser inner tank and helps to fight hard water. Results in long tank life.
  • TEMPERATURE CONTROL – Set the temperature of water as desired with the help of Adjustable Thermostat knob.
  • ENERGY EFFICIENT with SWIRL FLOW TECHNOLOGY – ENSURES 20% MORE HOT WATER; PUF INSULATION – Traps the heat inside the tank, to keep water hot for longer period, thanks to the Polyurethane foam inserted between the outer and inner shells of water geyser body.
Racold Omnis DG 25L Vertical 5 Star Storage Water Heater (Geyser) Sandstorm Gold|Digital Display| Touch Control|Auto Diagnosis| Suitable for High Rise Buildings|Free Standard Installation & Pipes
  • Titanium Plus Technology: Omnis DG water heater has superior durability and withstanding capacity. It has a specially designed titanium steel tank with titanium enamel coating and heating element which helps to resist pressure and water impurities
  • Silver-Ion Technology: The bacteriostatic effect in your water heater actively stops any increase of bacteria in water to provide healthy and clean bathing water, it prevents the growth of e-coli, salmonella and many more harmful bacteria
  • Auto Diagnosis: Omnis DG water heater has a revolutionary microprocessor that keeps all parameters in check automatically, This keeps you safe against electric shocks, sends you a notification and also shuts off automatically in case of any malfunction
  • Flexomix: The special deflector causes slow mixing of cold and hot water,keeping the water hot for a long duration and reducing the need for frequent restarts.This provides 10% more hot water than other geysers by controlling the inward flow of water
  • Safety Plus: This feature in your water heater provides you with 3 levels of safety against high temperature and pressure with cutout, thermostat and safety valve. A worry free shower for you and your family;BEE Star Rating: 5;Power: 2000 Watts
Racold BUONO PRO Storage Water Heater 10L – Vertical Geyser for Bathroom, 5 Star Rated, 3 Safety Levels, Rust Proof Body with Titanium Coating, Free Standard Installation & Pipes, White
  • TITANIUM PLUS TECHNOLOGY: Buono Pro water heater has a superior durability thanks to its specially designed titanium steel tank which helps to resist pressure and water impurities
  • SMART GUARD: Buono Pro has a special anode which performs an electrolytic process which protects the heating element from corrosion
  • RUST PROOF BODY: Buono Pro is specially designed to make it rust free, increasing his life
  • SAFETY PLUS: 3 levels of safety against high temperature and pressure, provided by a hightech adjustable thermostat, cut-out and multi function safety valve according to international standards
  • HIGH PRESSURE RESISTANCE: the water heater has high pressure withstanding capacity, which makes it suitable for high-rise buildings and high pressure pump applications

Do remember you can yourself insulate water heater too as properly insulating the tank of your electric water heater can help reduce heat loss. You can insulate the tank with a water heater blanket or jacket, and insulate hot water pipes to prevent heat loss while water travels from the tank to the faucets.