Hot Water Outlet | Gas storage hot water | Supply only
Rinnai Hotflo 135L Gas Storage Hot Water System
Buy the Rinnai Hotflo 135L as a supply-only gas storage water heater from Hot Water Outlet. Designed for outdoor replacement installations and medium-sized households, it combines 135L storage, 209L first-hour delivery and a 4.7 Star gas-efficiency rating. Select the correct natural gas or LPG model for your property.
Product overview
What is the Rinnai Hotflo 135L?
The Rinnai Hotflo 135L is a mains-pressure, outdoor gas storage hot water system. It retains hot water in a vitreous enamel-lined tank and uses a gas burner to replace heat as water is drawn, making it a practical candidate for replacing an existing external gas storage appliance.
Rinnai publishes a 209L first-hour delivery figure under a 45°C temperature-rise test. That figure differs from the tank’s 135L physical storage: first-hour delivery includes the hot water recovered during the hour, not additional tank volume.
For household sizing, Rinnai indicates use by up to five people in warmer climates or up to four in cooler climates, depending on flow rates and water-use patterns. Your licensed installer should confirm appropriate capacity and gas supply for the property.
HWO supplies the product — installation is separate
Hot Water Outlet does not directly install, connect or commission hot water systems. Customers may organise their own licensed gas fitter and plumber. In selected metro areas, HWO may assist with requesting quotes from independent licensed installers after purchase.
Benefits
Why choose the Hotflo 135L gas storage system?
A focused blend of capacity, controlled recovery, outdoor durability and connection details makes this model worth considering for like-for-like gas storage replacements. Every feature below relates to the 135L Hotflo rather than the larger 170L variant.
135L gas storage
Designed for households that prefer the familiarity of stored gas hot water, with hot water ready for showers, kitchen and laundry use.
209L first-hour delivery
Combines stored hot water and burner recovery. Rinnai tests first-hour output with a 45°C temperature rise from a 15°C cold-water supply.
4.7-star gas rating
Rinnai’s published energy-efficiency rating for this 135L Hotflo gas storage model; actual operating costs depend on demand, fuel price and conditions.
Natural gas or LPG
Choose GHF4135N for natural gas or GHF4135L for LPG/propane. Fuel types are separate product variants, not a universal gas setting.
External installation only
This gas storage system is designed for outdoor locations that meet Rinnai’s flue, ventilation, access and clearance requirements.
Vitreous enamel cylinder
A protective glass-like internal lining on the steel tank, with a sacrificial anode providing an additional corrosion-protection measure.
Automatic safety controls
Thermostatic temperature regulation and safety temperature shut-off support controlled gas water heating.
Replacement-friendly size
Its narrow case profile and defined connection positions are useful when assessing replacement of an existing outdoor gas storage heater.
Choose the correct fuel
Rinnai GHF4135N vs GHF4135L — natural gas or LPG
This product range is offered in two fuel-specific versions. Check your existing appliance’s data plate and the property’s available gas before ordering. A natural gas model must not be assumed to work on LPG, or vice versa.
GHF4135N — Natural Gas
Fuel: mains natural gas, where available and suitable.
Nominal burner gas consumption: 17 MJ/h.
Best suited to existing natural-gas storage replacement work where the gas pipework, regulator and installation location are compliant.
GHF4135L — LPG / Propane
Fuel: LPG / propane from a suitable approved supply.
Nominal burner gas consumption: 17 MJ/h.
Has LPG-specific gas-control commissioning requirements. An appropriately licensed gas fitter must verify gas pressure and the correct regulator arrangement.
Gas type must be confirmed before purchase
Both 135L fuel versions are rated at 17 MJ/h; this does not mean the units are interchangeable. The corresponding 170L Hotflo models have different gas consumption values and should not be used to specify this 135L heater.
Technical data
Rinnai Hotflo 135L technical specifications
Values are from Rinnai’s model-specific Hotflo gas storage product page, technical brochure and installation instructions. Appliance measurements are not a substitute for the complete site-clearance requirements.
| Specification | Rinnai Hotflo 135L / GHF4135 |
|---|---|
| Brand | Rinnai |
| Range | Hotflo Gas Storage |
| Product class | 135L external gas storage hot water system |
| Natural gas model | GHF4135N |
| LPG / propane model | GHF4135L |
| Gas variants | Fuel type is fixed by ordered model; confirm data plate |
| Stored water capacity | 135L |
| First-hour delivery | 209L at 45°C temperature rise, 15°C inlet |
| Recovery rate | 74L/h at 45°C temperature rise |
| Efficiency rating | 4.7 Star (gas storage) |
| Input — natural gas | 17 MJ/h |
| Input — LPG | 17 MJ/h |
| Installation location | External / outdoor only |
| Cylinder construction | Vitreous enamel lined steel |
| Corrosion protection | Internal sacrificial anode |
| Burner operation | Thermostatically controlled |
| Safety | High-temperature safety cut-out |
| Overall height | 1579mm |
| Overall width | 420mm |
| Overall depth | 508mm |
| Cold-water inlet height | 328mm from ground |
| Hot-water outlet height | 1316mm from ground |
| Gas inlet height | 276mm from ground |
| Gas connection | Rp 1/2 (15mm) |
| Hot and cold connections | Rp 3/4 (20mm) |
| Relief valve connection | Rp 1/2 |
| Empty unit weight | 68kg |
| Nominal full tank weight | At least 203kg for water plus dry unit, excluding fittings and other loads; installer to assess supporting base |
| Pressure and temperature relief valve | 1000kPa relief-valve setting |
| Expansion control valve (where required) | 850kPa setting |
| Maximum supply pressure with ECV | 680kPa |
| Maximum supply pressure without ECV | 800kPa |
| Pressure-limiting valve (if required) | 500kPa recommended |
| Indicative household size — warmer climate | Up to 5 people per Rinnai sizing guide |
| Indicative household size — cooler climate | Up to 4 people per Rinnai sizing guide |
| Domestic warranty — general parts & labour | 1 year, subject to Rinnai conditions |
| Domestic cylinder replacement guarantee | Up to 8 years total: replacement unit in years 2–8; owner pays transport, fitting and removal costs |
| Commercial use warranty | 1 year parts and labour as defined in Rinnai warranty booklet |
First-hour and recovery figures are manufacturer-rated test figures at a 45°C temperature rise; actual delivered hot water depends on inlet temperature, usage pattern and installation. Dimension diagrams and current data plates govern final fit.
Capacity and performance
135L storage versus 209L first-hour delivery
A storage system has two important numbers: how much heated water it holds and how quickly its burner replaces it. The Hotflo 135L stores 135 litres and is rated to provide 209 litres during the first hour under the specified testing conditions. Rinnai also lists a 74L/h recovery rate at a 45°C temperature rise.
Storage: 135L
This is the hot water capacity held in the insulated cylinder. It is relevant when showers or taps are used close together before the burner has had time to replenish the hot water supply.
First-hour rating: 209L
This is a manufacturer test measure that includes burner recovery while the unit is supplying water. It is not the size of the tank and should not be treated as a guaranteed daily delivery volume.
Households should be sized for actual fixture flow rates, incoming water temperature, overlapping shower use, demand patterns and local gas availability rather than using the number of occupants alone.
Placement and planning
Outdoor installation, measurements and connection checks
The Hotflo GHF4135 is an outdoor-only gas storage appliance. The manufacturer lists an overall height of 1579mm, a cabinet footprint of approximately 420mm wide × 508mm deep and 68kg empty weight. Gas-flue clearance, servicing access, drainage and a sound supporting surface must be assessed separately.
Before ordering
- Confirm natural gas GHF4135N or LPG GHF4135L.
- Check actual access routes and gate or path width for the delivery and future maintenance.
- Check the available space, heater flue position and the current Rinnai clearance diagram.
- Compare the existing plumbing and gas connection positions, plus the base and nearby openings.
- Confirm water pressure, safety valves, tempering protection and drainage needs.
Installer checks
- Licensed gas fitting and compliance to current gas standards.
- Correct regulator arrangement and gas pressure for the exact gas type.
- Proper support for the weight of a water-filled storage tank.
- Safe discharge from the temperature and pressure relief valve.
- Anode / water-quality suitability and appropriate service clearances.
Never install this model indoors
The GHF4135 appliance is specified for external use only. A location in a garage, enclosed alcove or other partially enclosed area must not be considered acceptable without formal assessment against Rinnai’s manual and applicable gas-installation rules.
Construction and maintenance
Vitreous enamel tank, sacrificial anode and safety protection
The steel cylinder incorporates vitreous enamel lining to protect its water-contact surfaces. The heater also contains a sacrificial anode, which helps protect metal components from corrosion and is a normal service item over the life of the heater. Water chemistry, pressure and maintenance affect cylinder life.
Rinnai lists a 1000kPa relief-valve setting, with an 850kPa expansion control valve where required. The manufacturer’s documentation shows a maximum supply pressure of 680kPa when an ECV is installed and 800kPa without an ECV; a 500kPa pressure-limiting valve is recommended where necessary. These are appliance specifications, not instructions for self-installation.
The licensed installer must select and install all required valves, discharge lines and tempering protection in accordance with the current Rinnai manual, local water conditions and applicable standards.
Which size?
Rinnai Hotflo 135L versus Hotflo 170L gas storage
Both belong to the Hotflo outdoor gas-storage family, but they serve different hot-water demand levels. Do not substitute the 170L dimensions, first-hour ratings or burner inputs for the 135L appliance.
| Comparison | Hotflo 135L — this product | Hotflo 170L |
|---|---|---|
| Storage capacity | 135L | 170L |
| First-hour delivery | 209L | 257L |
| Gas efficiency rating | 4.7 Star | 4.0 Star |
| Natural-gas burner input | 17 MJ/h | 20.5 MJ/h |
| LPG burner input | 17 MJ/h | 19.5 MJ/h |
| Overall height | 1579mm | 1915mm |
| Width × depth | 420 × 508mm | 420 × 508mm |
| Empty weight | 68kg | 83kg |
| Indicative warm-climate suitability | Up to 5 people | Up to 6 people |
| Indicative cool-climate suitability | Up to 4 people | Up to 5 people |
Rinnai’s household recommendations are indicative and depend on real demand. The 170L is a separate product requiring its own gas type and sizing checks.
Retailer terms
Buy Rinnai Hotflo 135L from HWO — supply only
Hot Water Outlet supplies the Rinnai Hotflo 135L as a standalone product for customers who want to organise licensed gas fitting and plumbing separately. This supports customers arranging their own preferred trades and those planning a like-for-like replacement.
What supply-only means
- The selected Rinnai Hotflo GHF4135 gas-storage water heater.
- Correct natural gas or LPG variant as specified on the order.
- Manufacturer-supplied components for that product configuration.
- Delivery when a supported postcode, freight route and address are confirmed.
What is not included unless quoted
- Gas fitting, plumbing labour or commissioning.
- New gas pipework, regulator work or compliance alterations.
- Temperature and pressure control/tempering valve kits or drainage changes.
- Removal/disposal of the existing appliance or base preparation.
- Travel, access, electrical or other site-specific work.
Product configuration, freight, accessory inclusions, prices and stock must be confirmed on the current HWO checkout listing. The product description does not promise that a particular accessory or service is supplied.
Delivery and separate trades
Metro delivery and independent installation quotes
HWO may offer delivery in selected metro areas around Brisbane, the Gold Coast, Sydney and Melbourne, with other locations subject to enquiry. Freight coverage, lead times, stock, site access and any delivery fee are confirmed for the actual delivery address; delivery is not guaranteed Australia-wide.
Hot Water Outlet does not directly provide installation services. Customers may independently engage licensed plumbers or gas fitters. In selected metro regions, after purchase, HWO may assist customers in requesting installation quotes from independent licensed local contractors. Availability and quote terms depend on location and the installer.
Ordering tip
Before paying, confirm gas type, selected product code, delivery postcode, access to the heater location and the installer’s requirements for valves, pressure controls and clearances. This reduces the risk of ordering an incompatible gas variant.
Warranty explained
Rinnai Hotflo 135L warranty and replacement guarantee
Rinnai’s GHF-series booklet distinguishes the first-year comprehensive warranty from the longer domestic cylinder guarantee. The eight-year claim is not an eight-year parts-and-labour warranty.
Year 1: covered parts and labour
The appliance and components have a manufacturer’s one-year parts-and-labour warranty for eligible manufacturing or workmanship defects, subject to Rinnai’s conditions and exclusions.
Years 2–8: domestic inner-cylinder replacement
Where the inner cylinder fails from a covered cause during this period, Rinnai provides a replacement water heater at the nominated approved point. The owner is responsible for the transport, removal, installation and labour costs associated with replacement.
Commercial use as defined by Rinnai generally receives one year of parts-and-labour coverage rather than the extended domestic cylinder guarantee. Rinnai’s definition of domestic use includes some residential accommodation settings, so assess the actual application using the warranty booklet. Water quality, proper installation, pressure, unauthorised modifications and maintenance requirements can affect eligibility.
The manufacturer’s written terms and consumer guarantees under Australian law prevail. Always review the warranty booklet applicable to the unit supplied.
Answers
Frequently asked questions — Hotflo 135L
Helpful answers for choosing the correct Rinnai Hotflo 135L gas storage system, arranging supply-only delivery, and preparing for a separately licensed installation.
Can I buy the Rinnai Hotflo 135L from HWO supply only?
Yes. Hot Water Outlet sells the unit as a supply-only product. Plumbing and gas fitting are separate from the product purchase.
Does Hot Water Outlet install this hot water system?
No. HWO does not directly install hot water systems. Where available in selected metro areas, HWO may help customers request installation quotations from independent licensed trades after purchase.
Can I get an installation quote after I buy?
Customers in eligible locations may request assistance sourcing an installation quote from a separate licensed plumber or gas fitter. Availability is not guaranteed and any quoted installation is independent of supply.
Is Australia-wide delivery guaranteed?
No. Delivery is available in selected metro service areas and depends on product availability, freight access and the delivery address. Confirm costs and availability before ordering.
What is the difference between GHF4135N and GHF4135L?
GHF4135N is for natural gas and GHF4135L is for LPG/propane. Choose the variant that matches the property’s gas supply and have it confirmed by a licensed gas fitter.
Can I use the natural gas model with bottled LPG?
No. Do not assume the gas variants are interchangeable. Buy the correct factory-specified gas model for the site. Gas work and any authorised conversion must only be considered under Rinnai instructions and applicable regulations.
Can the Hotflo 135L be installed indoors?
No. Rinnai specifies external installation only for the GHF4135 range.
How much water does the tank hold?
The rated storage capacity is 135 litres.
How much hot water is delivered in the first hour?
Rinnai publishes 209 litres for the first-hour delivery test at a 45°C rise from 15°C inlet water. This is a test figure, not a promise of 209 litres at every draw temperature or usage pattern.
What is the recovery rate?
Rinnai lists 74L per hour at a 45°C temperature rise. Recovery can vary with gas supply and operating conditions.
What gas efficiency rating applies?
The Rinnai Hotflo 135L is rated 4.7 Star under its published Australian gas storage rating.
What is the gas consumption for natural gas?
The GHF4135N is rated at 17 MJ/h.
What is the gas consumption for LPG?
The GHF4135L is also rated at 17 MJ/h. The fuel-specific ratings differ for the larger 170L model, so do not mix the two model specifications.
How tall is the Rinnai Hotflo 135L?
The overall height is 1579mm. Allow for access and the installation clearances required by Rinnai; do not treat the appliance dimensions as minimum cavity dimensions.
What are the width and depth?
The published cabinet width is 420mm and depth is 508mm. Nearby walls, flue position and gas connections may require more working space.
How much does the unit weigh?
The dry, empty appliance weight is 68kg. The filled system will be substantially heavier; a suitable level base is required.
Which water connections are fitted?
Hot and cold connections are Rp 3/4 (20mm). The external gas inlet is specified as Rp 1/2 (15mm) in the installation guide.
What pressure relief valve setting does it use?
The Rinnai-listed pressure and temperature relief valve setting is 1000kPa. The installer must follow all valve and discharge requirements in the current manual.
Do I need an expansion control valve or pressure-limiting valve?
This depends on water pressure, local plumbing rules, the site and water supply. Rinnai lists an 850kPa expansion control valve where required and recommends a 500kPa pressure-limiting valve where required.
Is it suitable for a household of four or five?
Rinnai indicates up to five people in warm-climate use and up to four in cool-climate use. Demand, shower duration, flow rates and daily usage determine whether this size is appropriate.
What is the cylinder warranty?
For domestic use as defined by Rinnai, the first year has a comprehensive parts-and-labour warranty. If the inner cylinder fails due to a covered fault during the following seven years, Rinnai provides a replacement unit but the owner pays associated removal, delivery, installation and labour costs. Conditions apply.
Does the eight-year warranty cover labour for eight years?
No. The extended domestic cylinder guarantee provides a replacement unit for eligible faults, not eight years of free replacement labour or transport.
Does commercial use receive an eight-year cylinder guarantee?
Not under the warranty booklet for the GHF range. Rinnai describes a one-year parts-and-labour warranty for applications it defines as commercial use. Some accommodation use is defined separately as domestic use; consult the booklet.
Can it replace a different brand of 135L gas storage heater?
It may be suitable where the gas supply, outdoor clearances, plumbing connections, pressure, base, access and compliance requirements all match. The existing system’s dimensions alone are not enough to confirm a straightforward replacement.
What is different about the Hotflo 170L?
Rinnai’s 170L model stores more water and has 257L first-hour delivery, compared with 135L and 209L on this model. It is taller and uses different gas inputs depending on fuel.
Does a 4.7-star rating guarantee a particular gas bill?
No. The rating supports model comparison. Actual cost depends on tariffs, usage, ambient conditions, hot-water temperature and other factors.
What maintenance should be planned?
Have the unit checked and serviced in accordance with the Rinnai manual by qualified personnel, including anode condition and safety-valve requirements. Water quality can affect cylinder life and warranty coverage.
Is the pressure-temperature relief valve included?
Rinnai identifies a pressure and temperature relief valve with the system. Other valves, fitting kits, pipework and compliance upgrades should not be assumed to be included in HWO’s supply-only offer.
Can I install the water heater myself?
No. Gas storage systems require appropriately licensed gas-fitting and plumbing work carried out to the manufacturer’s instructions and Australian standards.
Does HWO guarantee delivery to Brisbane, Gold Coast, Sydney or Melbourne?
HWO may deliver to selected metro areas around these cities, but coverage, stock, access, fees and timing must be confirmed for the address before ordering.
Tempering Valve and Element Information
*Element size information:
All electric hot water units are supplied as standard with a 3.6kW element unless otherwise stated on the product page, invoice, or order confirmation.
If a different element configuration is requested, such as 1.8kW or 2.4kW, the hot water unit may still arrive with the standard 3.6kW element fitted from the manufacturer. The requested 1.8kW or 2.4kW element will be supplied separately with the order for installation by a suitably licensed electrical contractor or licensed electrical licence holder.
Any element changeover, electrical connection, disconnection, wiring, testing, or modification must be carried out by a licensed electrical contractor or licensed electrical licence holder. Elements must not be changed, connected, modified, or tested by an unlicensed person.
Alternative elements supplied for non-standard configurations may be generic replacement elements and may not be the same brand as the hot water unit unless specifically stated. Generic elements are supplied to suit the requested element size and electrical configuration, but final suitability must be checked by the licensed installer before installation.
1.8kW and 2.4kW elements supplied separately with a hot water unit include a 12-month supply-only parts warranty from the date of purchase, provided the element has been correctly installed by a licensed electrical contractor or licensed electrical licence holder and used under normal operating conditions.
This element warranty covers the replacement supply of the element only. It does not include labour, call-out fees, electrical work, plumbing work, fault finding, removal, reinstallation, testing, travel, downtime, damage caused by incorrect installation, or any other associated costs. Warranty may be declined where the element has been incorrectly installed, dry-fired, modified, damaged, connected to incorrect voltage or wiring, affected by power issues, used in unsuitable water conditions, or installed by an unlicensed person.
Proof of purchase, installer details, electrical licence details, photos, and/or return of the faulty element may be required before a warranty claim is approved.
**Tempering valve information:
Where a hot water system is capable of delivering water above 50°C, a compliant tempering valve must be installed to control the temperature delivered to personal hygiene fixtures such as showers, baths, basins, and bathroom outlets. This helps reduce the risk of scalding and assists with meeting plumbing compliance requirements.
A tempering valve blends hot and cold water to deliver a safer controlled outlet temperature to required fixtures. The hot water unit itself may store water at a higher temperature, but the water delivered to personal hygiene outlets must be controlled where required by plumbing regulations.
If your property already has a suitable, compliant tempering valve installed, your licensed plumber can assess whether it is appropriate for use with the new hot water system. Existing valves may not always be suitable due to age, condition, compliance requirements, valve type, location, or system compatibility.
If a compliant tempering valve is not already installed, or if the existing valve is unsuitable, one must be supplied and installed by a licensed plumber as part of the hot water installation.
Tempering valves are not automatically included with every supply-only hot water unit unless specifically selected, listed as included, or purchased as part of a suitable valve kit. If a tempering valve is required, please purchase the appropriate valve kit with your order or arrange for your licensed installer to supply and install the correct tempering valve on site.
It is the customer’s responsibility to ensure the installation is completed by appropriately licensed trades and that all required valves, fittings, electrical work, plumbing work, and compliance requirements are allowed for as part of the installation.
Buying a new hot water system or hot water part should be simple. Hot Water Outlet helps you compare hot water systems, valves, thermostats, elements, pipework and fittings in one place, so you can choose the products that suit your home, budget and hot water needs without the back and forth.
Whether you already know exactly what you need or you are still comparing electric, gas, instant gas, gas storage or heat pump hot water options, Hot Water Outlet makes it easier to order with confidence.
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Key specs, sizing details, tank capacity, flow rate, gas type, energy source, dimensions, warranty information, product features and suitability notes are shown clearly, so you can compare hot water systems properly before you buy.
Valves and Accessories Available
Where relevant, you can add common hot water parts such as tempering valves, pressure relief valves, duo valves, non-return valves, thermostats, elements, pipework and fittings to help complete your order.
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Important Note
Product suitability can vary by property, existing services, energy source, gas type, available space, connection points, pressure requirements and local compliance requirements. Always check product specifications carefully and confirm the selected hot water system, valves, fittings and accessories are suitable for your property before ordering.
Standard Delivery: 2–8 business days
Express Delivery: 1–4 business days
90% of products are delivered the next business day where stock, postcode eligibility and freight availability allow.
Delivery timeframes are estimates and may vary by product, stock location, delivery postcode, carrier availability and order timing. Wet weather, storms, flooding or unsafe site access may delay delivery and are additional to any advertised or guaranteed freight timeframes.
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