RANGE OF AVAILABLE REPLACEMENT SYSTEMS
Rinnai Hotflo 135L Natural Gas Storage Hot Water System – GHF4135N
The Rinnai Hotflo 135L Natural Gas Storage Hot Water System is an outdoor mains-pressure water heater designed for medium-sized households wanting conventional stored hot water with natural gas recovery.
The GHF4135N provides 135L storage capacity, 209L first-hour delivery, approximately 74 L/hr recovery at a 45°C temperature rise and a 4.7 Star energy rating. Rinnai lists the 135L Hotflo for up to 5 people in warm climates and up to 4 people in cool climates under its published sizing guidance.
Installed Today offers the Rinnai Hotflo 135L Natural Gas as a supply-only water heater or with supply and installation across eligible Brisbane and Gold Coast service areas.
About the Rinnai Hotflo 135L Natural Gas Water Heater
The Hotflo 135L stores heated water in a vitreous-enamel-lined steel cylinder and automatically operates its gas burner to reheat the tank as the stored-water temperature falls.
Unlike a continuous-flow gas system, the Hotflo keeps a reserve of hot water ready for use. This makes it particularly relevant when replacing an existing external Natural Gas storage water heater without changing to instantaneous gas, electric storage or heat-pump technology.
The 135L is the smaller model in Rinnai's current Hotflo gas-storage range, with a larger 170L model available where greater storage and first-hour delivery are required.
Who Is the Rinnai Hotflo 135L Natural Gas Best For?
Medium-Sized Households
Rinnai lists the 135L Hotflo for up to five people in warm climates and up to four people in cool climates, depending on hot-water usage.
Natural Gas Storage Replacements
The GHF4135N is particularly relevant where an existing outdoor Natural Gas storage water heater is being replaced and the gas supply, plumbing and location remain suitable.
Multiple Hot-Water Outlets
Rinnai designs the Hotflo range for mains-pressure hot-water delivery to multiple outlets. Actual fixture flow still depends on incoming pressure and the property's plumbing.
Rinnai Hotflo 135L Natural Gas Key Details
*Rinnai provides a comprehensive one-year parts-and-labour warranty and, for domestic use as defined by Rinnai, an additional replacement guarantee if the inner cylinder fails within eight years. Replacement transport, installation and labour after Year 1 are subject to Rinnai's full warranty terms.
GHF4135N Natural Gas Configuration
This page covers the GHF4135N Natural Gas model only.
Rinnai publishes Natural Gas consumption of approximately 17 MJ/hr for the 135L Hotflo.
The appliance must be connected to the correct gas supply specified on its data label and installed and commissioned by an authorised person.
If the property uses bottled LPG rather than mains Natural Gas, the GHF4135N is not the correct variant. The LPG version is a separately configured appliance.
How Many People Does the Rinnai Hotflo 135L Suit?
Warm Climate
Rinnai lists the 135L model for up to 5 people in warm-climate conditions.
Cool Climate
Rinnai lists the 135L model for up to 4 people in cool-climate conditions.
Rinnai's published sizing assumes efficient outlets. Actual suitability depends on shower duration, fixture flow rates, baths, kitchen and laundry use and how closely household demand occurs together.
209L First-Hour Delivery
Rinnai publishes 209 litres of first-hour delivery for the Hotflo 135L.
First-hour delivery combines available stored hot water with water reheated by the burner during the first hour of draw-off.
Rinnai's Hotflo gas-storage technical information also publishes a recovery rate of approximately 74 L/hr at a 45°C temperature rise.
Rinnai's first-hour performance figures are based on stated test conditions and should not be interpreted as a guaranteed volume at every household fixture.
Key Features of the Rinnai Hotflo 135L Natural Gas
4.7 Star Gas Storage
Rinnai publishes a 4.7 Star energy rating for the current 135L Hotflo gas-storage model.
Vitreous Enamel Cylinder
The steel storage tank uses a vitreous-enamel lining designed to help protect the internal cylinder surface.
Sacrificial Anode Protection
An internal sacrificial anode forms part of the tank's corrosion-protection system and is replaceable as part of scheduled servicing.
Mains-Pressure Hot Water
The Hotflo is designed to provide mains-pressure stored hot water to connected household outlets.
Thermostatic Gas Control
The gas system is thermostatically controlled and incorporates safety temperature shut-off protection.
Lead-Free Compliance
Rinnai's current installation documentation states that the Hotflo gas-storage range complies with the lead-free requirements of the National Construction Code Volume 3.
Rinnai Hotflo 135L Natural Gas Specifications
| Specification | GHF4135N |
|---|---|
| Brand | Rinnai |
| Range | Hotflo Gas Storage |
| Product Code | GHF4135N |
| Gas Type | Natural Gas |
| System Type | Gas storage hot-water system |
| Installation | External / outdoor only |
| Storage Capacity | 135L |
| First-Hour Delivery | 209L |
| Recovery Rate | 74 L/hr at 45°C rise |
| Energy Rating | 4.7 Star |
| Warm-Climate Guide | Up to 5 people |
| Cool-Climate Guide | Up to 4 people |
| Natural Gas Consumption | 17 MJ/hr |
| Hot & Cold Water Connections | Rp 3/4 / 20mm |
| Gas Connection to Gas Controller | Rp 1/2 |
| Relief Valve Connection | Rp 1/2 |
| PTR Valve Setting | 1000 kPa |
| Expansion Control Valve | 850 kPa where required |
| Maximum Water Pressure With ECV | 680 kPa |
| Maximum Water Pressure Without ECV | 800 kPa |
| Recommended PLV | 500 kPa where required |
| Tank Construction | Vitreous-enamel-lined steel |
| Anode Protection | Sacrificial anode |
| Empty Weight | 68kg |
| Full Weight | 203kg |
| Domestic Warranty | 1 year parts and labour plus inner-cylinder replacement guarantee through Year 8 |
Rinnai Hotflo 135L Dimensions
| Dimension | Measurement |
|---|---|
| Overall Height | 1579mm |
| Overall Width | 420mm |
| Overall Depth | 508mm |
| Cold Water Inlet Height | 328mm |
| Hot Water Outlet Height From Ground | 1316mm |
| Hot Water / PTR Port Height Above Cold Inlet | 988mm |
| Gas Pipe Height | 276mm |
| Gas Pipe Depth | 459mm |
| Water / PTR Port Depth | 210mm |
| Empty Weight | 68kg |
| Full Weight | 203kg |
Allow additional room for gas pipework, water valves, the flue terminal and future servicing. Rinnai also requires overhead access for sacrificial-anode replacement.
The Rinnai Hotflo 135L Natural Gas Is External Use Only
The GHF4135N must be installed outdoors. It is not designed for internal installation.
Rinnai requires the appliance to stand on a permanently level, stable and clean-draining surface suitable for the water heater.
The flue terminal must maintain the required clearances from windows, doors, building openings and other structures in accordance with Rinnai's installation instructions and applicable gas-installation requirements.
Allow Space Above the Water Heater
The sacrificial anode is accessed through the top of the appliance.
Rinnai specifies approximately 50% of the water-heater height as overhead clearance for anode replacement.
For the 1579mm-high 135L model, this means the position beneath eaves, shelves or other permanent obstructions should be checked carefully before installation.
Natural Gas Supply & Connection Requirements
The GHF4135N must be connected to a suitable Natural Gas supply and installed by an authorised person.
Rinnai specifies gas-pipe sizing in accordance with applicable gas-installation requirements. The gas pipework must also be clean and correctly purged before the water heater is commissioned.
The data label on the appliance must be checked to confirm the gas type before installation.
Rinnai Hotflo 135L Water Pressure Requirements
Rinnai specifies a maximum direct water-supply pressure of 800 kPa where an expansion-control valve is not fitted.
Where an 850 kPa expansion-control valve is fitted, the published maximum supply pressure is 680 kPa.
Rinnai recommends a 500 kPa pressure-limiting valve where pressure limiting is required. The final valve arrangement must comply with the manufacturer's instructions and applicable plumbing requirements.
1000 kPa Pressure & Temperature Relief Valve
Rinnai supplies the Hotflo gas storage water heater with a 1000 kPa Pressure & Temperature Relief valve.
The PTR valve must be installed directly into its designated connection and connected to a compliant drain line that continuously falls toward the discharge point.
The appliance must not be operated without the correctly rated relief valve installed and operational.
Mains-Pressure Hot Water to Multiple Outlets
Rinnai describes the Hotflo gas-storage range as providing mains-pressure hot water to multiple taps.
The 135L storage tank and gas recovery can support normal household demand across showers, kitchens and laundries where the system is correctly sized.
Actual flow and pressure at individual fixtures still depend on incoming pressure, valves, pipe sizing and the property's plumbing layout.
Stored Water Temperature & Scald Protection
The Hotflo gas storage system uses thermostatic temperature control together with safety temperature shut-off.
Stored hot water can reach temperatures capable of causing serious scalding, so appropriate delivery-temperature control must be provided for relevant personal-hygiene outlets where required.
The final temperature-control arrangement should be determined by the licensed installer in accordance with current plumbing requirements.
Sacrificial Anode & Water Quality
The Hotflo 135L uses a sacrificial anode as part of the cylinder's corrosion-protection system.
Rinnai supplies a magnesium-alloy anode for typical water supplies. Where Total Dissolved Solids exceed 600 mg/L, Rinnai specifies an aluminium-alloy anode where the water remains within the manufacturer's permitted water-quality limits.
Water quality can affect servicing requirements, cylinder life and warranty eligibility.
Rinnai Hotflo 135L vs 170L Gas Storage
| Feature | Hotflo 135L | Hotflo 170L |
|---|---|---|
| Storage Capacity | 135L | 170L |
| First-Hour Delivery | 209L | 257L |
| Recovery @ 45°C Rise | 74 L/hr | 87 L/hr |
| Warm-Climate Guide | Up to 5 people | Up to 6 people |
| Cool-Climate Guide | Up to 4 people | Up to 5 people |
| Energy Rating | 4.7 Star | 4 Star |
| Overall Height | 1579mm | 1915mm |
The larger 170L model provides more stored water and higher first-hour delivery. Correct sizing should consider actual household demand rather than household size alone.
What Is Required to Install the Rinnai Hotflo 135L Natural Gas?
Rinnai requires the appliance to be installed, commissioned, serviced and removed by an authorised person.
- GHF4135N Natural Gas model matched to the property
- Outdoor-only installation location
- Permanent level and stable supporting surface
- Compliant flue-terminal clearances
- Rp 3/4 compatible hot and cold water pipework
- Correct Natural Gas pipe sizing and isolation
- 1000 kPa PTR valve installation
- Suitable isolation and non-return valve arrangement
- 850 kPa expansion-control valve where required
- Pressure limiting where incoming pressure requires it
- Compliant PTR drainage
- Suitable delivery-temperature control
- Safe tray where required by the installation conditions
- Access to gas controls and service components
- Overhead clearance for sacrificial-anode replacement
- Installation compliant with applicable plumbing and gas requirements
Buy the Rinnai Hotflo 135L Natural Gas Supply Only
Choose supply only if you require the GHF4135N and already have an appropriately licensed plumber or gas fitter arranged.
The supply-only price covers the selected water heater itself. Installation, site-specific valves, gas fitting work, plumbing alterations, pressure-control equipment, drainage, supporting-base work, old-system removal and disposal are separate unless specifically included in the order.
Before ordering, confirm that the property is connected to Natural Gas and that the existing installation position and services are suitable for the GHF4135N.
Rinnai Hotflo 135L Natural Gas Supplied & Installed
Supply Only
Order the GHF4135N where suitable licensed Natural Gas installation is already arranged.
Brisbane Installation
Eligible Brisbane customers can check supply-and-install options for replacement of a compatible external Natural Gas storage water heater.
Gold Coast Installation
Eligible Gold Coast customers can also check installation options including gas supply, pipework, water pressure, valves, access and compliance requirements.
Buy the Rinnai Hotflo 135L Natural Gas Across Australia
Installed Today offers supply-only ordering across supported Australian delivery areas, subject to product availability, with local supply-and-install options available in eligible Brisbane and Gold Coast locations.
Customers outside the local installation area can arrange compliant installation with an appropriately licensed local gas fitter or plumber.
Rinnai Hotflo 135L Natural Gas Installation Brisbane
Eligible Brisbane customers can order the GHF4135N with a local installation option where available.
A compatible replacement is generally more straightforward where the existing appliance is already an external Natural Gas storage system and the gas pipe sizing, water pipework, valves, pressure, supporting surface and flue clearances remain suitable.
The unit is approximately 1579mm high × 420mm wide × 508mm deep and approximately 68kg empty, so delivery access and servicing clearance should be checked before ordering.
Rinnai Hotflo 135L Natural Gas Installation Gold Coast
Eligible Gold Coast customers can also check supplied-and-installed options for the GHF4135N.
Before installation, confirm the property has Natural Gas and check the existing gas supply, pipe sizing, water pressure, valves, supporting base, external clearances and removal requirements for the old water heater.
Check These Items Before Ordering Installation
- Relocating the gas water heater
- Existing property uses LPG rather than Natural Gas
- Gas pipework alterations or resizing
- Gas isolation or compliance work
- Old, missing or non-compliant water valves
- Additional hot or cold water pipework
- Pressure-limiting or expansion-control equipment
- PTR drain alterations
- Tempering or delivery-temperature compliance work
- Unsuitable supporting base or plinth
- Restricted service or overhead access
- Non-compliant flue-terminal location
- Safe-tray work where required
- Removal and disposal of the existing water heater
Rinnai Hotflo 135L Maintenance
Every 6 Months
Rinnai instructs the owner to operate the PTR-valve easing lever for approximately 10 seconds and confirm that water discharges correctly and the valve closes again.
Major Service Every 5 Years
Rinnai recommends a licensed-trade service including replacement of the PTR valve and sacrificial anode together with draining and flushing of the storage tank.
Where Total Dissolved Solids exceed 600 mg/L, Rinnai recommends the major service interval be reduced to approximately 3 years.
Rinnai Hotflo 135L Natural Gas Warranty
Rinnai's current warranty provides different coverage depending on the application.
| Coverage | Domestic Use as Defined by Rinnai | Commercial Use |
|---|---|---|
| Parts & Labour | 1 year | 1 year |
| Inner Cylinder | Replacement guarantee if the inner cylinder fails within 8 years | No additional 8-year domestic cylinder guarantee |
| Replacement Installation After Year 1 | Subject to Rinnai's warranty terms and owner costs | Subject to commercial warranty terms |
For domestic use as defined by Rinnai, the manufacturer provides a comprehensive one-year parts-and-labour warranty and a guarantee to replace the hot-water unit if the inner cylinder fails within eight years.
Rinnai's definition of domestic use extends beyond ordinary houses to certain accommodation applications. Other commercial applications receive different coverage.
Always refer to Rinnai's complete current warranty terms for eligibility, exclusions, water-quality requirements and replacement costs.
Questions About the Rinnai Hotflo 135L Natural Gas
What is the Natural Gas product code?
The Natural Gas model is GHF4135N.
Is this page for the LPG version?
No. This page is specifically for the Natural Gas GHF4135N. Properties using LPG require the separately configured LPG model.
How much water does the Hotflo 135L store?
Rinnai specifies a 135 litre storage capacity.
What is the first-hour delivery?
Rinnai publishes 209 litres of first-hour delivery.
What is the recovery rate?
Rinnai publishes approximately 74 L/hr at a 45°C temperature rise.
How many people is the Rinnai Hotflo 135L suitable for?
Rinnai lists the 135L model for up to 5 people in warm climates and up to 4 people in cool climates, depending on usage.
What is the energy rating?
Rinnai publishes a 4.7 Star energy rating for the 135L Hotflo.
What is the Natural Gas consumption?
Rinnai specifies approximately 17 MJ/hr.
Can the GHF4135N be installed indoors?
No. Rinnai specifies the Hotflo gas-storage range for external use only.
Does it provide mains-pressure hot water?
Yes. Rinnai describes the Hotflo range as providing mains-pressure hot water to multiple outlets. Actual fixture performance depends on incoming pressure and household plumbing.
What are the dimensions?
The water heater is approximately 1579mm high × 420mm wide × 508mm deep.
How much does it weigh?
Rinnai specifies approximately 68kg empty and approximately 203kg full.
What water connections does it use?
The hot and cold water connections are Rp 3/4 / 20mm.
What is the gas connection?
Rinnai specifies an Rp 1/2 connection to the gas controller, with final pipe sizing determined by the licensed gas installer.
What is the PTR valve setting?
The supplied Pressure & Temperature Relief valve is rated at 1000 kPa.
What is the expansion-control valve setting?
Where an ECV is required, Rinnai specifies 850 kPa.
What is the maximum water pressure?
Rinnai publishes 680 kPa maximum with an ECV and 800 kPa maximum without an ECV.
What pressure-limiting valve does Rinnai recommend?
Rinnai publishes a recommended 500 kPa PLV where pressure limiting is required.
Does the Hotflo 135L have an anode?
Yes. The tank uses a sacrificial anode as part of its corrosion-protection system.
How much overhead service access is required?
Rinnai specifies approximately 50% of the water-heater height above the appliance for sacrificial-anode replacement.
Does the GHF4135N require professional installation?
Yes. Rinnai states that installation, commissioning, servicing and removal must be completed by an authorised person.
How often should the PTR valve be checked?
Rinnai specifies operation of the PTR easing lever approximately every 6 months.
How often is major servicing recommended?
Rinnai recommends a major service approximately every 5 years, reduced to 3 years where Total Dissolved Solids exceed 600 mg/L.
What is the warranty?
For domestic use as defined by Rinnai, the system receives 1 year parts and labour plus an inner-cylinder replacement guarantee if the cylinder fails within 8 years, subject to Rinnai's complete terms.
Can I buy the Rinnai Hotflo 135L Natural Gas supply only?
Yes. Installed Today offers a supply-only pathway where suitable licensed installation is already arranged.
Can Installed Today install the GHF4135N?
Supply-and-install options are available in selected Brisbane and Gold Coast service areas. Final requirements depend on Natural Gas availability, gas pipework, water pressure, valves, outdoor clearances, access and applicable compliance requirements.
Why Order the Rinnai Hotflo 135L Natural Gas From Installed Today?
Installed Today provides a clear pathway to order the Rinnai Hotflo 135L Natural Gas as a product-only purchase or combine it with an eligible local installation option. Confirm Natural Gas supply, household sizing, water pressure, gas pipework, valves, outdoor clearances, service access and old-system removal requirements before checkout.
Is the Rinnai Hotflo 135L Natural Gas Right for You?
The Rinnai Hotflo GHF4135N is suited to medium-sized households wanting to retain a conventional outdoor Natural Gas storage hot-water system. Its 135L tank, 209L first-hour delivery, 4.7 Star rating and mains-pressure operation make it particularly relevant as a replacement for an existing external Natural Gas storage heater.
Before ordering, confirm that the property is connected to Natural Gas and check household demand, gas pipework, water pressure, installation clearances and future service access. Choose supply only where compliant licensed installation is already arranged, or check Installed Today's Brisbane and Gold Coast installation options.
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DELIVERY TIMES WITH INSTALLATION - HOT WATER SYSTEMS EXC. HEAT PUMPS
Greater Brisbane and Gold Coast (EXCLUDING BAY ISLANDS) - up to 2 business days
Toowoomba, Tweed Heads and Sunshine Coast - up to 3 business days
DELIVERY TIMES WITHOUT INSTALLATION - HOT WATER SYSTEMS EXC. HEAT PUMPS
Greater Brisbane and Gold Coast (EXCLUDING BAY ISLANDS) - up to 3 business days
Toowoomba, Tweed Heads and Sunshine Coast - up to 5 business days
Harvey Bay, Cairns and Townsville - up to 5 business days
Metropolitan Cities - up to 5 Business Days
Listed Metropolitan Centers - up to 10 Business Days
DELIVERY TIMES WITH INSTALLATION - HEAT PUMPS
Greater Brisbane and Gold Coast (EXCLUDING BAY ISLANDS) - up to 2 business days
Toowoomba, Tweed Heads and Sunshine Coast - up to 5 business days
DELIVERY TIMES WITHOUT INSTALLATION - HEAT PUMPS
Greater Brisbane and Gold Coast (EXCLUDING BAY ISLANDS) - up to 5 business days
Toowoomba, Tweed Heads and Sunshine Coast - up to 5 business days
Metropolitan Cities - up to 5 Business Days
Listed Metropolitan Centers - up to 10 Business Days
DELIVERY TIMES WITH/WITHOUT INSTALLATION - PUMPS AND WATER FILTERS
Greater Brisbane and Gold Coast - up to 5 business days
Toowoomba, Tweed Heads and Sunshine Coast - up to 5 business days
Harvey Bay, Cairns and Townsville - up to 10 business days
**PLEASE NOTE ORDERS OUTSIDE OF THESE AREAS WILL BE REFUNDED AS SOON AS POSSIBLE**
SERVICED METROPOLITIAN CENTRES & CITIES
-Brisbane (EXCLUDING BAY ISLANDS)
-Gold Coast
-Sunshine Coast
-Toowoomba
-Coffs Harbour
-Tamworth
-Canberra
-Sydney (EXCLUDING ISLANDS)
-Bathurst
-Melbourne
-Ballarat
-Geelong
-Adelaide
-Perth
-Darwin
-Cairns
-Townsville
-Harvey Bay
-Rockhampton
-Bundaberg
-Tweed Heads
-Wollongong