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Bosch Gas Continuous Hot Water

Yunca Group are distributors of the Bosch comprehensive range of Gas Water Heaters, providing continuous hot water at mains pressure.

Why Bosch Hot Water?

  • ECONOMY: You only pay for what you use, as you use it. (Rather than paying to heat and maintain all the water in storage, regardless of how much you use).
  • NO MORE ripple control! What you need, when you need it.
  • MAINS PRESSURE hot water for your shower.
    • Full 10-Year (parts) Warranty on the Heat Exchanger system (this is a full replacement warranty, not pro rata). The full replacement warranty has been offered since 1990.
    • 3 Year (parts and labour) Warranty

When it comes to lighting the imagination, BOSCH is at the forefront of innovation. Use the quick links to the left of this page to take you directly to the sections below.

BOSCH HydroPower - The new generation of hot water systems.

Internal Compact or External

BOSCH HydroPower (Internal)BOSCH HydroPower (External)

Enjoy the convenience of a hot water system that needs no power or battery to operate!

That's right - No power connection required, so you can forget about installing a power outlet next to your new hot water system, replacing batteries that have died or trying to light an extinguished pilot light. Installation costs are reduced, still plenty of hot water, and did we tell you it works when the power is off.

HydroPower needs no additional energy source – only water and gas are required, ensuring easy installation and reduced energy consumption.

HydroPower from Bosch is the answer.

Introduced in New Zealand in 2003 exclusively by Bosch, HydroPower uses the energy created by water flow to ignite the burner and begin the heating process. The revolutionary Bosch HydroPower ignition system means you can still have a hot shower, even in the most remote areas or when mains power is not available. The unit only ignites when a hot water tap is opened, providing endless hot water at the turn of a tap. Once the hot water is turned off, the unit turns itself off. Simple.

The HydroPower range can be operated in relatively low water and gas pressure areas. Capable of providing from 10 – 16 litres per minute, they are able to suit many domestic applications. Higher flow rates can be achieved by manifolding (coupling) two or more units together.

All Internal heaters must be flued (purchased separately), every part of the flue must be in the vertical plane.

  • Energy Efficient - up to 5.3 star rating for economical operating costs
  • Environmentally Friendly - water is heated only as required, unit made from 100% recycled materials
  • Continuous Flow - Heats up to 960 litres of hot water per hour
  • HydroPower Ignition - requires no pilot light and saves on gas
  • Ideal for Holiday Houses - with gas turned off unit can be safely left for long periods
  • Flame Failure Device - gas supply shut-off if flame extinguishes
  • Copper Heat Exchanger - ensures long life
  • Can Replace Other Hot Water Systems - provided water and LPG or Natural gas connections exist
  • Available in Natural or LPG gas

Internal models are:

  • Designed to mount on an Internal Wall - needs no special mounting but all internal units require a vertical flue system (purchased separately).
  • Small, compact design – perfect for small homes where space is limited.
  • Temperature Control and digital display - user friendly controls select desired temperature and flow rate

External models are:

  • Designed to mount on an outside wall (a heat shield accessory is required for combustible surfaces, e.g. weatherboards).
  • An Anti frost Exogel valve is essential for External models in areas where the temperature drops below zero for short periods. In those areas where extended periods of very low temperatures are experienced then the Internal Compact models are recommended.

The following tables list specifications for the HydroPower models.

Compact Internal HydroPower SPECIFICATIONS
  Model Ci10 Ci13 Ci16
  Part # GWH10-2G GWH13-2G GWH16-2G
  Input Mj/Hr 79 100NG / 97LPG 127
  Flow Rate 25 degrees C Rise (min) 10L 13L 16L
  Star Rating 5.3 4.5 4.6
  Gas Type NG, LPG NG, LPG NG, LPG
  Min. water pressure 50 kPa 50 kPa 50 kPa
  Min constant water pressure for Max. Flow 100 kPa 140 kPa 170 kPa
Piping Dimensions Gas NG 20mm (3/4") 20mm (3/4") 20mm (3/4")
  Gas LP 15mm (1/2") 15mm (1/2") 15mm (1/2")
  Cold water 15mm (1/2") 15mm (1/2") 15mm (1/2")
  Hot water 15mm (1/2") 15mm (1/2") 15mm (1/2")
Unit Dimensions Height (mm) 580 655 655
  Width (mm) 310 350 425
  Depth (mm) 220 220 220
  Flue pipe size 100 125 125
Warranty (Domestic use) Parts & Labour
3 Years
  Heat Exchanger
(Part only – full cost)
10 Years
External HydroPower SPECIFICATIONS
  Model 10H 13H 16H
  Part # TF-250-8G TF325-8G TF-400-8G
  Input Mj/Hr 79 104 130
  Flow Rate 25 degrees C Rise (min) 10L 13L 16L
  Star Rating 5.1 4.6 5
  Gas Type NG, LPG NG, LPG NG, LPG
  Min. water pressure 50 kPa 50 kPa 50 kPa
  Min. water pressure for Max. flow 60 kPa 100 kPa 130 kPa
Piping Dimensions Gas NG 20 mm (3/4") 20 mm (3/4") 20 mm (3/4")
  Gas LP 15 mm (1/2") 20 mm (3/4") 20 mm (3/4")
  Cold water 15 mm (1/2") 20 mm (3/4") 20 mm (3/4")
  Hot water 15 mm (1/2") 20 mm (3/4") 20 mm (3/4")
Unit Dimensions Height (mm) 845 845 936
  Width (mm) 405 405 460
  Depth (mm) 265 265 265
Warranty Parts & Labour
3 Years
  Heat Exchanger (Part only - full cost)
10 Years
Accessories Antifrost Exogel Valve
H 707 060 151
  Heat Shield
9 708 01 400

The Highflow Electronic Ignition Range (External)

The Highflow Electronic Ignition 26eThe Highflow Electronic Ignition 26 eco+

Size Matters!

Bosch are proud to present the latest technology in hot water systems, the Bosch Highflow. These gas water heaters are now the most compact of their type on the New Zealand market today. All models boast compact dimensions so your hot water heating is now even less obtrusive.

More control!

These technologically advanced units are electronically controlled and are most effective when coupled with optional controllers. Up to four controllers can be fitted to deliver temperatures accurate to single degrees, and thereby achieving considerable savings in gas costs during high demand (bathing and showering). The controllers can be installed in the kitchen (or laundry), the bathroom and the ensuite. The units can also be installed without controllers and the water temperature is then determined by mixing the cold water tap at each outlet by the user.

More Choice!

Our premium appliances will provide unlimited hot water for your hot water applications. The Bosch Highflow Electronic Range can cater perfectly to your demands - from 17 to 26 litres of hot water per minute. For higher flow rates, units of the same model can be manifolded (coupled) together. Older models can easily be adapted to use as solar booster for hassle free solar hot water options.

Solar Compatible!

In 2011 all Bosch Highflow units will be solar compatible. This means you will no longer incur the additional expense of a separate solar transfer valve when linking to a solar hot water system.

The 21e is already solar compatible, the 26e units will be compatible early in 2011, followed by the 17e later in the year. If you particularly require solar compatible units, please make sure you are supplied the correct model type (identified by the letters RAH after the model number. (excludes ECO models).

More Efficient!

The Highflow range is extremely efficient and delivers hot water at a predetermined temperature selected by the consumer. For added safety all Bosch Electronic water heaters come factory set to 55°c. The temperature can also be adjusted at the unit to cater for various specialist applications such as Child Care Centres (37°c), Nursing Homes (43°c) and higher temperatures for Commercial Kitchens (75°c).

NEW! BOSCH 26 ECO+ with 6.9 Star Energy Rating!

Condensing technology utilises exhaust temperatures in a secondary heat exchanger for maximum efficiency. The ONLY gas hot water system that includes a neutraliser (heat from the exhaust gas is collected within the secondary heat exchanger, condensation occurs, and resulting acidic water is drained. Neutraliser is specifically designed to transform the condensate into a neutral, environmentally friendly emission).

Accessories (available on Highflow models only) include Recess Boxes - meaning your hot water system can be built into the wall, and Pipe Covers - for covering pipe work underneath the appliance.

  • Continuous Flow Hot Water - heated only as required, up to 26 litres/min.
  • Energy Efficient means lower operating costs – Better than 5.5 star rating for 17e, 21e and 26e models. The ECO26+ has a Star Energy Rating of 6.9
  • Unique Bath Filling /Water stop function (when controllers fitted) - Stops the water flow and alerts you when the desired volume and temperature is reached
  • Digital Display Controllers - including time of day and water temperature
  • Priority switch - will override main controller if safety is threatened
  • Call Button on Controllers - for elderly or disabled requiring assistance in the bathroom
  • Constant Water Temperature - computer controlled
  • Fault Diagnostic Display - in-built computer control checks functions and records any problems
  • 3 year warranty on parts and labour. 10 years on heat exchanger (part only)
Highflow Electronic Ignition SPECIFICATIONS
  Model 17e 21e 26e 26eECO+
Part Number YS1770RAH YS2170RAH YS2670RAH BC2600RA
Solar Compatible Mid 2011 YES Early 2011 NO
Input Mj/Hr 135 170 200 178
Flow Rate 25o C Rise (min) 17L 21L 26L 26L
Star Rating 5.66 5.56 5.53 6.9
Gas Type
Standard - Electronic
Min. operating inlet water pressure
Min. water pressure for Max. flow 100kPa 130kPa 230kPa 200kPa
Unit Dimensions Height (mm) 520 520 600 600
Width (mm) 350 350 350 350
Depth (mm) 170 170 170 260
Piping Dimensions Gas NG
20 mm (3/4")
Gas LP
20 mm (3/4")
Cold water
20 mm (3/4")
Hot water
20 mm (3/4")
Warranty (Domestic) Parts & Labour
3 Years
Heat Exchanger
10 Years
Accessories Max. Number of controllers
Recess Box
RBHF304WD (n/a for ECO26)
Pipe Cover
YPHC304 (n/a for ECO26)



In addition to our impressive range of domestic gas hot water heaters is the next generation of commercial hot water heating technology, the Bosch 32 series. Featuring heavy duty heat exchangers and special coatings, the 32 series is available in the following models:
KM3211WH (power flue),
KM3211WHQ (ringmain unit with built in pump and power flue), and
BC32OORA (ECO condensing).

All models may be installed internally (flue system required) or externally, and are available in either LPG or NG. The Bosch 26e (external only) may be adapted for commercial use, allowing a temperature range between 37 and 75 degrees. For specifications please refer to the table above.

Internal / External Applications - Unique to Bosch!

The Bosch units can be installed either internally (requires 100mm twin wall flue), or externally with the additional Bosch accessory, Vent Cap (KMVC100) making the Bosch 32 series the most flexible units on the market.A range of accessories are available to further enhance your options and comfort.

The 32 litre commercial units are specifically designed for New Zealand commercial use. Options include one unit through to a fully manifolded system. The Bosch commercial units have all your applications covered. The 32 series has a coated copper heat exchanger to prevent corrosion and deterioration and the internal copper piping is 25% thicker than residential models to extend the life of the product. In addition, the Quick Connect Cord (KMQC0703339) is available for easy installation of 2 units manifolded for heavier applications. The Bosch 32 and 32Q will, with a controller attached, reactivate within 1 minute of the power coming back on after a power outage and go back to the settings that it had before the loss of power (great for sporting complexes).

Both the 32 and 32Q feature the same physical dimensions. Antifrost comes as a standard option with the 32 series.

The 32 series are most effective when coupled with the temperature controllers. The controllers offer fingertip water temperature control, accurate to single degrees. The commercial controller gives you the advantage of not having to mix hot water with cold water as this is done automatically inside the unit. Bosch has also developed a range of Professional Packs, including burner and tank, available to be shipped to your site for installation. The packs come in a range of different sizes from a 250ltr tank + 200mj burner to a 315ltr tank + 250mj burner.

The unique features of the Bosch 32 and 32Q include:

  • 32 litres per minute.
  • Main and sub remote controllers and cables (as accessories)
  • Either LPG or NG.
  • External applications with vent cap accessory
  • Internal applications with standard flueing (e.g. available from any plumbing outlet).
  • 4.8 stars.
  • Wall mounted.
  • Minimum pressure - 200 kPa.
  • Capacity range 3.5 - 32ltrs minute.
  • Direct ignition
  • Temperature settings - 37-48, 50, 55, 60, 65, 70, 75, 80 C
  • Safety devices - flame rod, thermal fuse, pressure relief valve, lightning protection device (ZNR), electric leakage prevention device, overheat prevention device, freezing prevention device, fan rotation detector
  • 25 degree rise @ 32ltrs per minute
  • Compact design
  • Easy installation

Additional Features of the 32Q

  • Main controller (RCM3211) included as standard with 32Q models
  • Internal Pump - The internal pump is the additional benefit of the 32Q unit. This enables the consumer to not require an external pump for the system saving initial setup costs, space and for ease of installation for recirculating systems.
  • Recirculation feature means there is always hot water in the pipes
  • Circulation Mode - Main controller has a built in timer for recirculation pump

Additional features of the 32C Condensing

  • The new Bosch 32C sits at the top of the range as the most efficient Commercial gas hot water unit on the market today.
  • 6 Star energy rating
  • This product innovation utilises a dual heat exchanger created from a fusion of stainless steel and copper heat exchangers. The 100% stainless steel component captures the residual heat from the exhaust gas to preheat the incoming water prior to the water entering the main copper heat exchanger - making the appliance over 94% efficient.
    • Has the ability to operate with solar hot water/warm water return systems making it compatible with high efficient solar systems.
    • In-built neutraliser for the safe release of condensate (ph neutral condensate)
  Model 32 32Q 32C
Part # KM32111WH KM32111WHQ BC3200RA
Input Mj/Hr 250 250 200
Flow Rate 25 C Rise (min) 32L 32L 32L
Star Rating 4.8 4.8 6
Gas Type NG, LPG
Antifrost Standard
Type Internal (100mm twin wall flue req'd) or External
Air Supply / Exhaust Power vented
Min. water pressure for Max. flow 200 kPa
Min flow rate 3.5 L / minute 3.5 L / minute 2.5 L / minute
Piping Dimensions Gas 20 mm (3/4")
  Cold water 20 mm (3/4")
Hot water Outlet 20 mm (3/4")
Hot water Return - 15 mm (1/2") -
Unit Dimensions Height (mm) 615
  Width (mm) 464
Depth (mm) 240
Warranty: COMMERCIAL Parts & Labour 2 Years
  Heat Exchanger (Part only) 5 Years
Warranty: DOMESTIC Parts & Labour 3 Years
  Heat Exchanger (Part only) 10 Years
Accessories: Max. Number of controllers 3


Enhance your hot water supply system by manifolding units together and/or combining with Bosch Everlast tanks.

Manifold two units together using Quick Connect cable (part number KMQC0703339).

3 – 6 units can be manifolded using a System Controller with either a 3m or 5m cable.



Bosch Everlast storage tanks are made of Marine Grade 316 Stainless Steel. The advantages are many: Stainless steel is approximately twice as strong as mild steel, used by glass lined (vitreous enamel) cylinders. Stainless steel is a natural barrier to corrosion and rust. Stainless steel can withstand temperatures up to 100°C (Glass lined cylinders can start dissolving between 70°C and 85°C and can start to crack the glass as expansion and contraction occurs). Stainless steel does not require sacrificial anodes to protect against rust. Stainless steel tanks do not introduce any contaminates such as rust or anode residue into the water, which can happen with glass lined cylinders.

  • Two models of stainless steel tanks are available, both are 315 litres with either 32mm ports (315C2) or 50mm ports (315C250)
  • Tanks can be purchased separately


A wide of range of commercial applications can be achieved. From a single unit (either internal or external) to manifolded systems with or without storage tanks.

To view the range of commercial application options download the Commercial brochure in pdf format here.



All Bosch Highflow units will soon be Solar Compatible, without the need for special Solar Boost valves. 21e units are already compatible, the 26e will be compatible early 2011, and the 17e by mid 2011. Solar compatible units feature "RAH" after the model number.

Those units not yet compatible may have a solar valve connected to enable solar boost.

Your Solar Hot water systems will work for you 24 hours a day, every day, regardless of weather conditions or high demand usage.

For safety reasons a tempering valve is required to ensure a maximum 55°c, whether boosted or not.

  • For those that want to get the most out of their solar hot water system Solar Boost provides the best option for year round, night and day, hot water. As the Boost ONLY operates when the solar hot water is below temperature – and then only enough to restore it – it is the most efficient and economical solution available.
  • External mains power connection required for Highflow unit.
  • Solar collector, storage and valves purchased separately.


The Bosch range of premium accessories caters for the extra needs of today’s modern hot water consumer.

Bosch water heater units are able to operate in relatively low water pressure areas and in near freezing weather temperatures by utilising Bosch Accessories.

Optional Bosch temperature controllers, recess boxes, pipe covers and various other accessories all feature in this category to enhance your water heating experience!




The Bosch Highflow range is most effective when coupled with optional premium temperature controllers.

The controllers offer fingertip water temperature control, accurate to single degrees and provide the added feature of Bosch Water Saver. Achieve savings on gas costs by heating only to the temperature required during heavy use (showering or bathing). E.G. Heat water to 39°c for a shower / bath, then revert to normal temperature use (50 or 55 degrees).

  • Available for all Bosch Highflow appliances - 17e, 21e and 26e.
  • Option of up to four Temperature Controllers (Main / Bathroom / Sub Control)
  • Digital Display Controllers - including time of day and water temperature
  • Unique Bath Filling function - stops water flow and alerts you when the desired volume and temperature is reached (Main and bathroom controls only)
  • Call Button on Controllers - for elderly or disabled requiring assistance in the bathroom
  • Constant Water Temperature - set and forget.
  • Achieve savings on gas costs by heating only to the temperature required during heavy use.
  • Fault Diagnostic Display - in-built computer control checks functions and records any problems

Almost completely conceals unit, the housing is built into the wall. Conceals the plumbing to the unit.
Saves space. Available for non-recessed units
Ready painted. Easy access.



  • Only available for the Bosch External HydroPower Ignition Range
  • Prevents freezing water from damaging the appliance.
  • Designed for units installed in areas susceptible to frost and freezing temperatures however antifrost valves DO NOT provide protection against extreme (sub zero) or prolonged low temperatures (below 3 degrees). In such cases consider installing Internal HydroPower units.
  • Part Number H 707 060 151


  • Use where External HydroPower unit is to be installed on a combustible surface (eg. weatherboard)
  • 850mm x 400mm
  • Part number 9 708 061 400.7G1


Remote Controllers

The Bosch 32 series is most effective when coupled with temperature controllers. The controllers offer fingertip water temperature control, accurate to single degrees. The commercial controller gives you the advantage of not having to mix hot water with cold water as this is done automatically inside the unit.

Main Remote Controller

  • Timer display (current time)
  • Error display
  • High temperature display
  • Temperature setting e.g. 40°c
  • Burner on display eg. this is displayed when the burner is on
  • Circulation mode - this is displayed when circulation mode is on
  • On / off button
  • Cannot have a sub controller without a main controller
  • Maximum of 3 controllers can be fitted to the 32, 32Q and 32C, being 1 Main controller and up to 2 Sub controllers

Sub Controller

  • On / off button
  • Burner on display eg. this is displayed when the burner is on
  • Temperature setting eg. 40°c
  • Error display
  • Priority indicator

Vent Cap

  • For external installations only
  • KMVC (pictured) for 32, 32Q
  • BCVC-100C for 32C

Flue Kits (Bosch 32 internal installations)

FKV32LTR (vertical flue kit) and FKH32LTR (horizontal flue kit, vent cap also required) are available for internal installation of the Bosch 32 / 32Q models. A polypropylene flue is required for 32C, refer to Yunca for pricing and details).

Quick Connection Cable KMQC0703339

  • For 2 units manifolded together

System Controller KMSC201

  • For manifolds of 3 - 6 units

Cable for system controller (3 or 5 metres)

  • KM0700073 (3m)
  • KM0700075 (5m)