The best instantaneous water heaters

The compact “flow tank” Thermex Surf 3500 is intended for producing hot water for domestic purposes. The model is suitable for non-pressure water supply systems - when connected to a centralized water supply, a reduction reducer or valve is installed in front of it to regulate the intensity of the flow. A spiral heating element with a power of 3500 W is responsible for heating water in the design of the device. The boiler must be plugged into a reliable grounded outlet, and a 16 A circuit breaker must be installed on the line to it.

With an average flow rate of about 2 l/min. The boiler increases the water temperature by approximately 25 °C. It can be installed either with the terminals facing down or up. At the same time, the model implements protection against dry operation - if there is no water flow, the spiral heater automatically turns off. This prevents potential problems with equipment failure.

Out of the box, the Thermex Surf 3500 is equipped with a shower hose with a shower head and a nozzle holder. And for the convenience and speed of installation of the water heater, a special mounting panel on the wall is provided separately. The “flow tank” must be operated in closed heated rooms. It will serve as a convenient solution for small apartments with small kitchens and bathrooms.

The compact and inexpensive instantaneous electric water heater Tesy IWH 35 X02 KI is designed to serve one water collection point. The device is a flat plastic case with a tap and handles for adjusting the supply of hot and cold water. Inside the case there is a heating coil that heats the water flowing through the “insides” of the device. The power of the heating element is 3500 W. When you open a tap marked in red, the device turns on automatically (and when closed, it turns off automatically in the same way). The water temperature is adjusted solely by changing the strength of the jet in the “red” tap. As the flow increases, the temperature decreases, and as the flow decreases, it increases. With an average flow (2 l/min), the water heater manages to increase the temperature of the water flowing inside it by 25 °C. If you only need cold water, then use the “blue” tap. It is not connected in any way to the heating element and does not turn on the device.

This water heater is suitable exclusively for non-pressure water supply systems. That is, when connecting to a centralized water supply, a reduction reducer or valve will need to be installed in front of the device into the cold water supply line to regulate the pressure. The water heater faucet is “slipped” directly onto the cold water pipe protruding from the wall (it should be a standard 1/2″ size). There is a coarse filter inside the water heater that traps small solid particles. It should be cleaned periodically. The housing is attached to the wall using two screws and two dowels, for which holes must first be drilled. Considering the power of 3500 W (as an electric kettle and an electric stove combined), the device’s plug can only be plugged into reliable sockets that can withstand current up to 16 A.

Electric heaters like the Tesy IWH 35 X02 KI are great for installing above a kitchen sink or next to a washbasin in a garage, workshop or office restroom. Although you won’t get boiling water from this device, it can cover basic needs and provide warm water, allowing you to rinse your hands or wash dishes.

The compact water heater Atlantic Ivory IV202 does not require much space for installation and effectively copes with heating running water. The model is assembled in a molded plastic case with lower water supply inlet and outlet pipes. It is capable of working in pressure systems. A “wet” copper heating element is installed at the heart of the device, supporting smooth power adjustment in the range from 550 W to 5500 W. The flow rate is supposed to be changed using a complete shut-off valve installed at the inlet.

The model is designed to work with one water point, be it in the kitchen or bathroom. To avoid boiling of water and burns of users, the “flow tank” has protection against overheating - the heating element automatically turns off when the water temperature reaches 90 °C. Atlantic Ivory IV202 provides proper water heating at a flow rate of 2 l/min.

At the inlet and outlet of the boiler, coarse water filters are installed to remove large mechanical impurities. And for using the model in the shower, the device includes a watering can, a flexible hose and a wall-mounted shower stand. Excess pressure inside the water heater is released through a safety valve. “Protochnik” covers any basic needs for hot water supply and is assembled entirely from high-quality components.

The Hotpoint-Ariston AURES SF 5.5 COM instantaneous water heater (the name AURES SLIM FLOW is also found in online stores and equipment catalogs) is a budget solution from a well-known manufacturer, with which you can solve the problem of hot water in the kitchen or bathroom. Ariston, not without reason, praises the Italian design of this device, which indeed looks very aesthetic. Inside the elegant case there is a heating system of two tubular copper heating elements. One of them has a power of 2200 W, and the second - 3300 W (the total power of the water heater is therefore 5500 W). To control the operation of the device, two “twists” are used on the front panel. One of them is used to adjust the water pressure and performs the functions of a thermostat (when the knob is turned to the left, the pressure increases and the water temperature decreases, when turned to the right - vice versa). The second handle turns on the heating elements: the first, the second, or both at the same time (in this case, the LEDs on the panel show which of the heating elements is currently turned on). If no water flows through the water heater or the stream is too weak (a flow of at least 2 l/min is needed), then the heating elements will not turn on (this is how protection against overheating is implemented). By turning on both heating elements at the same time and turning the thermostat knob all the way to the right, you can achieve the maximum possible water temperature for this device - 55 °C.

The water heater is attached to the wall with four screws (fasteners of the required size are included in the kit). It must be installed exclusively in a vertical position with the pipes down. The device easily attaches to a standard water pipe with a 1/2″ thread. A tee with a tap and a shower head, which are included in the package of the water heater, is screwed to the second pipe. But the power cable is not included. Due to the power of 5500 W, a separate electrical cable (with a cross-section of at least 4 mm2) must be connected to the installation site of the flow-through heater from the distribution panel. The line must be grounded and protected by a 25 A circuit breaker. Due to the fact that the body of the Hotpoint-Ariston AURES SF 5.5 COM water heater has a high degree of protection (class IP25) from water and splashes, it can not only be suspended above a sink or bathtub, but also installed right inside the shower stall.

Like other water heaters of the same brand, the Bosch Tronic TR 1000 4T flow-through water heater has a very laconic design. It looks like a simple white parallelepiped of small size. But under the discreet body there is something interesting hidden - a heating system of an original design. It is designed as follows: water flows through a copper tube twisted into a spiral. A copper heating element of exactly the same spiral shape is laid between the turns of the spiral. The tube and the heating element are connected to each other using soldering. Thus, the heating element transfers its heat to the tube, which, in turn, heats the liquid. Such a water heater design ensures efficient water heating and gives reason to believe that the device will last a long time.

Water heaters of this series operate in fully automatic mode thanks to sensors that record the speed of water movement through the “insides”. The heating element turns on when the flow rate reaches 1.3 l/min, and turns off when the flow drops to 1 l/min. The standard productivity when heating tap water at a temperature of 12 °C to a comfortable 37 °C is 1.8 l/min. The device's protection systems consist of a temperature limiter, which will prevent the water heater from overheating and burning, and a waterproof housing (IP24D class), which prevents splashes from getting on the electrical components even if the device is doused with water.

The Bosch Tronic TR 1000 4T water heater has pipes facing upward, so it is best to install it under the sink in the kitchen or under the sink in the bathroom. The compact dimensions of the case (250x144x100 mm) make it easy to hide the device in a cabinet. The delivery set includes a mounting template, a set of fasteners (two dowels and two screws), as well as a wire with a plug and an aerator nozzle, which must be put on the faucet to reduce water consumption. The water heater should be connected to a grounded electrical network, protected by a 25 A circuit breaker. Difficulties can only arise when connecting to a cold water pipe. Although this heater can be connected to a pressure water supply, you may need to purchase a special fitting to do so. The fact is that the pipes of the device have a diameter of 3/8″, and the water pipes in your home most likely correspond to the standard size 1/2″.