Overview of gas boilers Kentatsu

Kentatsu gas boilers are products of a well-known Japanese brand. The company produces floor and wall-mounted devices, classic and condensing. All models are an example of an innovative approach to the creation of heating equipment.

About company. The history of “Kentatsu” began in 1887 with a small workshop. In 1933, the company took the name Kentatsu Denki. She constantly expanded her line of business: she produced typewriters, electrical appliances, equipment for submarines and ships. The brand entered the Russian market only in 2005 and could not but attract the attention of consumers – quality and reasonable price always arouse interest.

Installation options

Wall mounted  

Kentatsu Nobby Smart is the fruit of a collaboration with the German engineering concern Kentatsu Furst. These turbocharged double-circuit boilers work for heating and providing hot water. The control panel is digital, there are recessed knobs for setting parameters. The screen continuously displays the temperature of the heat carrier and water in the DHW circuit.

The series is compact. All have a closed firebox. It is convenient for installation in apartments. All models except 24-1CS are equipped with two separate heat exchangers. The primary is copper, the secondary is traditionally made of stainless steel.

A feature of this series is the ability to work at the lowest water pressure, even at 0,5 bar. In Nobby Smart, you can turn on the bithermic mode (weather-dependent control), this function is available for models included in the TOP segment. Efficiency – 93%.

Condensing

Kentatsu Smart Condens are double-circuit wall heaters that use additional energy for heating and domestic hot water. When fuel is burned, hot exhaust vapors are formed, in the classical design energy is lost, in the condensation design it is directed to heat the coolant and water. This series has a high efficiency – up to 108%, and is represented by modifications of 25, 30, 40 kW. Boilers are suitable for underfloor heating.

Equipped with a turbine – for air injection and vapor removal, and a circulation pump – for forced movement of the coolant. Both devices are modulating, changing power smoothly. This technology allows you to save fuel as much as possible. Work is possible on any type of gas.

Outdoor

The Kobold floor series is made of cast iron. These single-circuit devices are adapted to low and unstable gas pressure in the mains. The manufacturer used Amin Gas technology: hydraulic resistance compensation contributes to uniform heating of the heat exchanger. Power range within 20–000 W.

All modifications are distinguished by a stylish design. Despite the high technology, the devices are easy to operate, any user can handle them. They work singly or in cascade. Parameters are monitored continuously. All modifications are atmospheric – an open combustion chamber. Can be converted to LPG.

Models overview

Kentatsu Furst Nobby Smart 28–2CS 

Wall-mounted boiler of classical type. Turkish collection. 3 years warranty. Two circuits – heating and hot water. Heat exchangers of separate type. This design feature is especially important in hard water areas. It runs on natural gas, but, if the user wishes, it can be easily converted to liquefied gas, you just need to buy jets.

The control board must be powered from the mains 220 V. The manufacturer recommends (this is important for maintaining its warranty obligations) to install a voltage stabilizer. The combustion chamber is closed. There is a fan for supplying outdoor air and removing exhaust gases through a coaxial chimney.

Specifications:

• Economical gas consumption – 2,88 m³ / h.
• It can heat houses up to 280 m².
• Efficiency – 91,5%.
• Power (min / max) – 10,7 / 28,1 kW.
• Expansion tank – 7 l.
• Grundfos circulation pump.
• Heating temperature (min/max) – 35/85°C.
• “Summer” mode.
• DHW capacity – 12/8,6 l at 25/35°C.
• Weight – 35 kg.
• The cost is 29 rubles.
• Dimensions (HxWxD) – 730x403x345 mm.

Smart Condens 25

Condensing type model for heating and hot water heating. Heat exchangers are separate. Turkish collection. Warranty 1 year. Design features:

• weather-dependent control is provided;
• the thermostat is connected;
• turbocharged type;
• pump and burner are modulating.

Technical specifications:

• Gas consumption – 2,37 m³ / h.
• Efficiency – 108%.
• Expansion capacity – 7 l.
• The maximum pressure is 3 bar.
• The maximum heating area is 240 m².
• Weight – 34 kg.
• The cost is 60 rubles.
• Dimensions (HxWxD) – 840x470x420 mm.

Goblin-03

Floor single-circuit heater with cast-iron sectional heat exchanger. Design features:

• There is weather control.
• Worth automation Honeywell.
• Can operate at the lowest gas pressure.
• At the request of the user, an indirect heating boiler is installed.
• The cost is 46 rubles.
• Durability – works for at least 15 years.
• A cast iron heat exchanger is twice as resistant to corrosion as a steel counterpart. Such modifications are allowed to work in low temperature mode.
• Volatile, the control board is connected to the mains. You need a voltage stabilizer.
• Open firebox. Combustion air is taken from the room. Therefore, it must be equipped with ventilation. The products of combustion are discharged through a stationary vertical chimney, thanks to natural draft.
• Power (min / max) – 10,7 / 28,1 kW.
• Expansion tank – missing.
• Grundfos circulation pump.
• Heating temperature (min/max) – 35/85°C.
• “Summer” mode.

Equipment

Consider the configuration of Kentatsu boilers using the example of the Kentatsu Furst wall model:

• French heat exchanger (primary) Gannoni. Transfers heat energy from gas combustion to the heat carrier. Material – copper. There is anti-corrosion protection, aluminum-silicon coating.
• Swedish heat exchanger (secondary) Swep. Heats domestic water. Attaches to two points. The special configuration of the plates increases the performance of the unit, this at low pressure gives high efficiency. The permissible pressure in water pipes is 10 bar.
• Gas valve – modulating (SIT). Thanks to power modulation, it is possible to ensure the stability of water heating.
• Italian burner Polidoro. Air and gas are mixed in advance. The result is silent combustion, modulation in a wide range, a minimum of waste, in accordance with European standards. Made from stainless steel.
• Italian fan Ln2. Removes exhaust gases from the furnace. There is a system that controls the presence of traction. Vibrations are damped, extremely low noise level.
• Danish Grundfos pump for coolant circulation. Several modes that allow you to adapt to any heating systems.
• Swedish pressure switch Huba control. Monitors the smoke exhaust system. In the event of an emergency, turn off the device.

Features of operation

Rules for the user:

• Do not damage or remove labels on equipment.
• Violation of the operating rules may result in damage and void the warranty.
• Installation is carried out by service centers with appropriate permits.
• Gas heaters are powered by electricity. Grounding is required. Connect to the circuit breaker using a cable with a cross section of 1,5 mm.
• It is forbidden to use pipes (gas, water) for grounding.
• When connecting, follow the instructions for the type of gas the equipment will be used with.
• If you have any problems, read the instructions. To repair serious damage, call the service.
• If you smell gas, turn off the gas heater and do not turn on electrical appliances. Shut off the gas with a valve, open all windows and doors in the room.

• Installation is carried out in accordance with project documentation, technical standards and manufacturer’s instructions.
• Hot water is a heat carrier and cannot be used for household needs.
• The water/antifreeze pressure must not drop below 1 bar. You need to check its level on the manometer.
• During a short shutdown, do not turn off the power supply and turn off the tap – so that the frost protection works.
• With a long shutdown, the gas valve is closed, the device is disconnected from the mains. To prevent the boiler, batteries and pipes from freezing, the water must be drained.
• In case of violation of the operating rules and in case of breakdowns resulting from this, the manufacturer disclaims warranty obligations.

Error codes “Kentatsu Furst”

When a malfunction is diagnosed, the key icon appears on the screen. The user needs to press Reset to display the code. The instruction contains a decoding of the codes – having learned the cause of the problem, the user eliminates it. Independently, if the malfunction allows you to manage on your own, or with the help of specialists – in serious cases. To reset the code, press and hold the Reset button.

Possible mistakes:

• LP – coolant pressure has dropped. If it is below ½ bar, the relay contacts are broken. For the control board, this situation is an error. As a result, the burner is blocked. Probable causes of the problem: malfunction of the expansion tank (no air), pressure decreased due to leakage, or the relay itself broke.
• AF – poor removal of combustion products. If the pressure switch contacts do not close when the fan is started, a breakdown of the smoke exhaust system is diagnosed. Causes: improper installation of the chimney, clogging of the fan blades, the fan or pressure switch is broken.
• Ht – the coolant does not circulate. The problem is diagnosed by determining the temperature of the NTC sensor. Causes: clogging of the cleaning filter, pump malfunction, air locks, shutdown of taps in the heating system, clogging of the impeller of the circulation pump.
• HL – overheating. If the water/antifreeze temperature exceeds +94°C, the corresponding sensor will be triggered. The contact is broken, the operation of the boiler is blocked. Reasons: the sensor responsible for overheating broke down, the circulation of the coolant was disrupted, the gas valve was not set to maximum pressure.
• bC – no fire in the burner. Causes: no fuel, tap closed, air lock, no ground loop, gas valve failure.
• GI – the valve modulation coil has broken.
• Fr is the threat of freezing. If the coolant cools down to +1°C, the “key” sign appears, the operation of the device is blocked due to low temperature. The reason is that the device was not switched to winter mode.

Reviews

Nobby Smart 18–2CS: Nikolai G., Kaluga

Reliable mid-range equipment at an affordable price. It heats water perfectly – there are no interruptions and you do not have to wait until it heats up. We connected sensors for the temperature outside – it works economically and maintains a stable temperature in the house. Minus – insufficiently detailed instructions.

Smart Condens 30–2CS: Roman L., Vladimir

Has been working flawlessly for two years now. Handsome in appearance. Functional, economical, does not cause anxiety with its work – it does not make noise, monitors the parameters. No quality issues. 

Kentatsu boilers confirm the reputation of Japanese manufacturers. In the domestic market, they are widely represented by a wide, consumers can choose a device of suitable power and performance. All heaters are characterized by a high level of automation and reliability.