The 3kW heating element is standard for instant geysers in India, but you should check the type and material of the heating element. Incoloy or copper heating elements are known for their durability and efficiency. Otherwise glass coated heating elements are the best. Only AO Smith provide glass coated heating element in Instant geysers in India.

Instant geyser must have safety features like a thermostat to prevent overheating and a pressure relief valve to release excess pressure. As the 3kw is considered high power which put a lot of load on wiring of the house specially old houses with decade old wiring. An ELCB inbuilt instant geyser are also need of the hour to avoid electric shock. Better to connect elcb plug/top separately to geyser.

AO Smith EWS Plus Instant Water Heater 3 Litre with 3kW Incoloy Heating Element | 8 Bar Pressure Rating for High-rise Building | Instant Geyser for Kitchen & Bathroom | 5-Year Tank Warranty
  • Premium and stylish aesthetics: EWS Plus is an outstanding design with premium aesthetics, redefining the instant water heater category. It is a perfect balance of form and function that will make your bathroom look magnificent and extraordinary.
  • Longer Life in HARD Water Condition: AO Smith’s patented Blue Diamond glass lining in its tank provides the best protection against corrosion, even in hard water conditions.
  • HIGH-POWERED INSTANT HEATING: Get instant hot water with a high-powered incoloy heating element. Glass coating on the element further enhances the life of the heating element.
  • Stronger construction quality with tank thickness of 2 mm, 2X compared to an ordinary instant water heater
  • 5-level safety shield for maximum protection: ISI marked Power cord added safety, Auto Switch on/off- No overheating., Pressure relief valve Protection against high-pressure buildup in the tank, Superior Quality Wiring U/L Rated wiring harness for added safety, Surface Mount sensing, Thermostat is mounted on the tank. Highly consistent and reliable. Adds to the safety, Rust Proof/ Shock Proof HIPS polymer outer body
Bajaj Splendora 3L 3kW Vertical Instant Water Heater For Home|Instant Water Geyser For Bathroom & Kitchen|High Grade SS Tank|Copper Heating Element|1-Yr Product 2-Yr Element 5-Yr Tank Warranty|White
  • ABS outer body with SS tank
  • Copper heating element with efficient longer life
  • Suitable for 6 bar pressure
  • Unique Weld free joint in outer metal body
  • It come with fire retardant cable and neon indicator for heating
AO Smith EWS-5 White Instant Geyser 5 Litre With 3kW Express Heating | High Rise Building Bathroom & Kitchen geyser | UL Rated Wiring & Pressure Relief Valve For Ultimate Safety | 5 Year Tank Warranty
  • INSTANT HOT WATER HEATER FOR YOUR HOME: Experience the comfort of instant water heater technology with our 3000-watt element. Whether for your bathroom or kitchen, this instant water heater delivers hot water in seconds, perfect for cold mornings.
  • DURABLE STAINLESS STEEL GEYSER 5 LTR: Our geyser 5 litre with a stainless steel tank is built to resist corrosion even in hard water. Designed for long-lasting performance, this 5 litre geyser ensures you enjoy dependable hot water every day.
  • ADVANCED SAFETY FEATURES FOR YOUR FAMILY: Stay protected with our electric geyser featuring a 5-level safety shield. From overheating control to a rust-proof body, this instant water heater for bathroom guarantees total peace of mind for you and your loved ones.
  • HIGH-PRESSURE READY FOR HIGH-RISE HOMES: Perfect for high-rise living, our water heater 5 litre handles up to 6.5 Bar pressure effortlessly. This hot water geyser for bathroom ensures consistent performance, even in multi-story buildings.
  • WORRY-FREE WARRANTY FOR YEARS TO COME: Invest in confidence with a 5-year tank warranty and 2-year product warranty. Our instant water heater is backed by comprehensive coverage, ensuring you get the best experience without worry.
Racold Altroi+ 3L 3KW Vertical Instant Water Heater (Geyser) White with Free Standard Installation & Pipes Smart LED Ring Free Electric Plug Convenient for Kitchen & bathroom, Wall Mounting
  • High Pressure Resistance: Your water heater has high pressure withstanding capacity, which makes it suitable for high-rise buildings and high pressure pump applications
  • Temperature Regulation Knob: An easy control knob through which you can regulate heating of water as per your requirement
  • Safety Plus: Three 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
  • Customized Application : It’s a unique, novel and first of its kind feature in the Instant water heater segment helps you in optimizing water heater usage . You can select ‘KITCHEN’ or ‘BATHING’ mode based on the intended hot water application
  • Smart LED Ring : The Smart LED Ring range senses when hot water is ready for bath, or other application and notifies user by changing LED color from blue to red
Havells Instanio 3L Instant Water Heater(Geyser)|Temp. Sensing LED Indicator| Rust & Shock Proof Body| ISI Marked|With Flexible Pipes|Warranty:5 year on Inner Tank| High Rise Compatible(White Mustard)
  • Type: Instant ; Capacity: 3 Litres; Wattage: 3000 Watts; Pressure: 6.5 Bars4 Level Safety : Thermostat, Automatic Thermal Cut-Out, Pressure Release Valve and Heating Indicator
  • LED : Temperature Sensing Color changing LED Indicator for real-time hotness of the water
  • Outer Body: Rust and shock proof Plastic outer body for long life
  • Heating Element : Copper heating element offers superior heating performance with its excellent resistance to both oxidation and carbonization at high temperature setting and resists corrosion against extreme and hard water conditions
  • Inner Tank : Extra thick Stainless Steel Inner tank of superior 304 Level grade​
Crompton Rapid Jet 3-L Instant Water Heater (Geyser) with Advanced 4 level Safety (White)
  • PRODUCT: Crompton’s smart instant water heater with powerful heating element
  • TECHNICAL SPECIFICATIONS: Wattage: 3000 W; Capacity: 3L; Pressure 6.5 bar
  • 4 LEVEL SAFETY: Capillary Thermostat, automatic thermal cut-out, pressure release valve and fusible plug
  • ANTI-SIPHON PROTECTION: Designed to prevent any backflow of water and protect the heating element from dry heating damage
Crompton Solarium Neo 3-Litre, 3KW Instant Water Heater/Geyser with Rust Free ABS Body (Ivory)
  • PRODUCT: Crompton’s energy efficient instant water heater with rust proof ABS body
  • TECHNICAL SPECIFICATIONS: Wattage: 3000 W; Capacity: 3L; Pressure 6.5 bar
  • 4 LEVEL SAFETY: Capillary Thermostat, automatic thermal cut-out, pressure release valve and fusible plug
  • ANTI-SIPHON PROTECTION: Designed to prevent any backflow of water and protect the heating element from dry heating damage
  • QUALITY COMPONENTS: ISI marked nickel coated special element to provide resistance against scale formation
Polycab Intenso 5 litre, 3KW Electric Instant Geyser (Water Heater) For Home, Bathroom | Efficient Heating Element | Enhanced Safety Measures | 5 years tank & 2 years product warranty【White Blue】
  • ✅【Efficient Heating Element】Experience instant hot water with the highly efficient heating element.
  • ✅【Durable Engineered Plastic Body】Our Water Heaters boasts a rust-proof engineered plastic body that ensures prolonged durability.
  • ✅【Enhanced Safety Measures】Polycab, known for its core value of Safety with its other electrical categories, incorporates advanced safety standards and internal fire retardant cables for unparalleled protection of your famil
  • ✅【Versatile Usage】 Our compact Water Heater design is perfect for both Bathroom & Kitchen applications.
  • ✅【 Coverage】 PRODUCT WARRANTY By Polycab – 2 year. Tank Warranty by Polycab – 5 years.
NEXOMS Cup Type Heating Element ISI Marked 3KW Compatible for 3 Litre – 6 Litres Instant Geysers
  • Tube Material: Anti-Corrosive Copper
  • Power: 3KW
  • Heavy Quality ISI Marked Element
  • Compatible for Portable Geysers and Instant Geysers 3 Litre to 6 Litres

Another thing to check is pressure bar capacity of inner tank specially if you like high rise buildings as water pressure can be much more for tank to withhold. You can also consider 4.5kw instant geysers if the house is fairly new with new wiring.