Function of instant water heater: The function of instant heater should provide hot water instantly and continuously as per the capacity of water tank. Since this is small 3L heater, it should provide hot water continuously with low flow rate. Nature of complaint: The water heater supplied by Sathya Agency is not working as per the required functionality. Once the heater is switched on, waited for 5 minutes, it provides 2 mug of water (3 litres) and then cold water is flowing continuously. If we close the water tap for 5 minutes again it provides 2 mugs of hot water and then hot water stops. Likewise, if want to take bath with minimum 20 mug of water, it will take 1 hour. This is not practically possible. So, this product should have either design issue or no proper service technician to rectify the problem. Finally, Sathya and Haier are saying that this heater is working properly and no complaints. Also, they are not ready to rectify the issues, provide replacement or exchange with other water heater manufactures.