Hot Water Outlet | Supply only | Natural gas
Rinnai Hotflo 135L Natural Gas Storage Hot Water System – GHF4135N
Buy the Rinnai Hotflo 135L Natural Gas water heater from Hot Water Outlet. Designed as an outdoor gas storage replacement for medium-sized Australian households, model GHF4135N combines a 135-litre tank with 209 litres of first-hour delivery, 4.7-star gas efficiency and durable vitreous enamel cylinder protection. Product supply only; installation is not included.
About the Rinnai Hotflo 135L Natural Gas
The Rinnai Hotflo GHF4135N is a natural gas-fired storage heater for outdoor residential applications. Unlike a continuous-flow heater, it stores a reserve of heated water ready for household use while the gas burner reheats the tank as hot water is drawn.
Rinnai rates this medium-capacity model for up to five people in warmer climates and up to four in cooler climates under its published sizing assumptions. Household demand, shower flow rates and duration, water temperature and simultaneous tap use all influence the best system size.
This page is exclusively for the GHF4135N natural gas model. If your property uses bottled LPG, this is not the correct fuel variant; choose the separately listed LPG model GHF4135L. Only an appropriately licensed gas fitter should verify the connection and installation.
Eight reasons to choose the Hotflo 135L
135L gas storage
Mains-pressure storage for medium-sized households already using natural gas.
209L first-hour delivery
Combines stored hot water and burner recovery under Rinnai test conditions.
4.7-star gas rating
Manufacturer-rated gas energy performance for the Hotflo 135L.
17 MJ/h natural gas input
Specified gas consumption for the GHF4135N natural gas variant.
Vitreous enamel protection
Glass-like tank lining and a sacrificial anode help protect the steel cylinder.
Outdoor model
Designed for external placement with compliant flue, access and clearances.
Replacement-friendly sizing
420mm wide, 508mm deep and 1579mm high; confirm the existing footprint.
8-year cylinder guarantee
For eligible domestic cylinder failures; coverage and labour conditions vary by year.
Order the Rinnai Hotflo 135L supply only
What you are buying
Hot Water Outlet supplies the Rinnai Hotflo GHF4135N natural gas water heater as a standalone product. Supply-only purchasing suits customers who already have an independent licensed gas fitter or plumber organised.
- GHF4135N natural gas storage water heater
- Manufacturer-supplied components according to the product packing list
- Selected-area delivery subject to postcode confirmation
What is not included
The listed supply price does not include labour or ancillary site work unless an offer expressly specifies otherwise.
- Plumbing, gas connection, commissioning and compliance work
- Replacement valve sets, pressure controls or additional fittings
- Existing heater disconnection, removal or disposal
- Base, drainage, pipework and site alterations
- Installer charges or permits where applicable
Natural gas model and fuel suitability
Rinnai manufactures gas-specific 135L Hotflo variants. This product is GHF4135N — natural gas. It must be matched to the fuel shown on the household supply and the appliance rating plate. Do not assume an LPG unit and a natural-gas unit are interchangeable.
| Variant | Fuel | Is this the product? |
|---|---|---|
| GHF4135N | Natural gas | Yes — this listing |
| GHF4135L | Propane / LPG | No — a separate fuel-specific model |
Rinnai lists 17 MJ/h gas consumption for the 135L model in both gas configurations; the fuel-specific appliance code remains essential.
Rinnai Hotflo 135L natural gas specifications
Figures below are drawn from current Rinnai Hotflo gas storage product material and its gas storage installation manual. Site conditions and manufactured versions should be checked against the delivered unit and its supplied instructions.
| Specification | GHF4135N natural gas |
|---|---|
| Brand | Rinnai |
| Series | Hotflo gas storage |
| Product | Hotflo 135L Natural Gas Storage Water Heater |
| Product code | GHF4135N |
| Fuel | Natural gas (NG) only |
| Alternative LPG model | GHF4135L — a separate product; not included here |
| Technology | Mains-pressure gas storage |
| Nominal storage capacity | 135L |
| First-hour hot-water delivery | 209L; manufacturer test conditions |
| Recovery rate at 45°C temperature rise | 74L per hour |
| Energy rating | 4.7 Star |
| Gas consumption, natural gas | 17 MJ/h |
| Gas consumption, LPG | Not applicable to this natural-gas product |
| Typical sizing, warm climate | Up to 5 people depending on demand |
| Typical sizing, cool climate | Up to 4 people depending on demand |
| Location | External / outdoor installation only |
| Tank construction | Vitreous enamel-lined steel |
| Cylinder protection | Inbuilt sacrificial anode |
| Heating control | Thermostatically controlled gas burner; safety temperature shut-off |
| Hot and cold water connections | Rp 3/4 (20mm) |
| Natural gas connection | Rp 1/2 (15mm) |
| PTR valve relief setting | 1000kPa |
| Expansion control valve setting, if required | 850kPa |
| Maximum supply pressure with ECV | 680kPa |
| Maximum supply pressure without ECV | 800kPa |
| Recommended pressure-limiting valve, if required | 500kPa |
| Overall height | 1579mm |
| Unit width | 420mm |
| Unit depth | 508mm |
| Hot water outlet height | 1316mm from base |
| Cold water inlet height | 328mm from base |
| Gas fitting height | 276mm from base, Rinnai technical brochure |
| Empty weight | 68kg |
| Domestic parts and labour warranty | 1 year, subject to terms |
| Domestic cylinder replacement guarantee | 8 years including first year, subject to terms; later-year labour and transport excluded |
| Commercial warranty | 1 year parts and labour, subject to Rinnai definition and terms |
All dimensions are approximate planning figures. Do not use product dimensions alone as minimum installation clearances; refer to the relevant Rinnai installation manual and local gas standards.
209L first-hour delivery and rapid recovery
The 135L tank is backed by a gas burner that heats incoming cold water as hot water is used. Rinnai lists 209 litres of first-hour hot-water delivery and a 74L/hour recovery rate at a 45°C temperature rise. These are manufacturer testing figures, not a guarantee of identical output at every home.
First-hour delivery is different from physical tank capacity. The 135L figure is the stored water volume; 209L is an indication of hot water supplied over the first hour while reheating takes place. Actual shower performance also depends on mixing temperature, fixture flow rates and timing of demand.
4.7-star natural gas efficiency
Rinnai rates the Hotflo 135L at 4.7 gas energy stars, with a listed natural-gas consumption of 17 MJ/h. The system is intended as a familiar gas storage replacement for suitable homes using mains natural gas.
Operating expense depends on gas tariffs, daily hot water consumption, standing heat losses, cold water temperature, age and condition of the existing heater, and installation quality. Gas stars should not be read as a guaranteed percentage saving against an individual existing system.
Planning an outdoor replacement
Fit, connections and access
- Confirm the 1579mm height and 420 × 508mm footprint
- Check the existing Rp 1/2 natural gas and Rp 3/4 water connections
- Allow space above for sacrificial anode maintenance
- Check gas flue separation from windows, doors and openings
- Provide an approved, stable, level and well-drained support surface
Valves and compliance
- Have a licensed installer confirm inlet water pressure
- Use compliant temperature and pressure relief arrangements
- Assess any expansion control or pressure limiting valve requirements
- Check tempering/mixing requirements at personal hygiene fixtures
- Check site drainage, safe tray requirements and access for servicing
The GHF4135N is not an indoor gas appliance. Rinnai specifies external installation and the current installation manual sets flue and service access conditions. Installation, gas testing and commissioning must be performed by an authorised professional.
Vitreous enamel lining and anode protection
The Hotflo 135L cylinder is steel lined with vitreous enamel, a glass-like layer intended to protect the tank's internal surface. An inbuilt sacrificial anode provides a further layer of cylinder corrosion protection. Both features support tank durability when the system is correctly selected, installed and maintained.
Water quality and maintenance matter. Rinnai's manual includes guidance on anode selection in harsh-water areas and recommends authorised servicing of safety valves and anodes at approximately five-year intervals, or more frequently under specified adverse water conditions. The appropriate service schedule should be confirmed against the supplied manual and local water quality.
Rinnai Hotflo 135L or 170L?
If your current gas storage heater is undersized or your household has grown, compare Rinnai's two Hotflo gas storage capacities before ordering.
| Manufacturer figure | Hotflo 135L NG | Hotflo 170L NG |
|---|---|---|
| Natural gas model | GHF4135N | GHF4170N |
| Tank capacity | 135L | 170L |
| First-hour delivery | 209L | 257L |
| Gas stars | 4.7 | 4.0 |
| Natural-gas consumption | 17 MJ/h | 20.5 MJ/h |
| Overall height | 1579mm | 1915mm |
| Empty weight | 68kg | 83kg |
These are manufacturer range figures for comparison only. The Hotflo 170L is a different product and is not included with this listing.
Supply-only delivery and optional quote assistance
Hot Water Outlet offers supply-only ordering with delivery to selected metropolitan areas, potentially including eligible addresses in Brisbane, the Gold Coast, Sydney and Melbourne. Delivery is not guaranteed for every postcode, and pricing, freight handling and timelines must be confirmed before an order is finalised.
HWO does not install gas hot water systems. In selected service areas, customers may request help obtaining separate quotes from independent licensed plumbing and gas-fitting businesses. Installer availability and quote assistance are not guaranteed and are not an installation contract with Hot Water Outlet.
Manufacturer warranty — understand what is covered
First year
Rinnai's Hotflo gas storage warranty specifies a comprehensive one-year parts-and-labour warranty for eligible defects in materials or workmanship, subject to the policy terms.
Years 2–8: eligible domestic cylinder failure
Rinnai guarantees a replacement hot-water unit for a qualifying inner-cylinder failure during the remaining seven years of eligible domestic cover. Transport, installation, disconnection and replacement labour are the owner's cost during this extended period.
Rinnai distinguishes domestic-use and commercial-use definitions. Commercial applications generally have one year of parts-and-labour cover, without the eight-year domestic cylinder replacement guarantee. Coverage is subject to installation, water conditions, maintenance, exclusions and Australian Consumer Law rights. Read the current warranty accompanying your product.
Frequently asked questions
Is this the natural gas or LPG Rinnai Hotflo 135L?
This listing is specifically for GHF4135N, the natural gas model. The separately coded GHF4135L is for LPG. Check the existing gas supply and the unit rating plate before ordering.
What is the model code?
GHF4135N. It is the 135L, natural gas, external-storage variant.
Can I buy the Rinnai Hotflo 135L natural gas supply only?
Yes. Hot Water Outlet sells the unit supply only, with delivery subject to your address and service availability. Plumbing and gas installation are excluded.
Does Hot Water Outlet install the product?
No. Hot Water Outlet does not directly install hot water systems. In selected areas, customers can request help seeking quotes from independent licensed installers.
Can HWO assist with an installation quote after purchase?
In selected metro areas HWO may be able to help you request quotes from independent licensed plumbers or gas fitters. This depends on location and availability, and is not part of the supply-only purchase.
Does supply only include a valve kit or removal of the old unit?
No. Supply only covers the selected heater. Fitting, gas and plumbing works, additional valves, removal, disposal and any site or compliance work are separate.
Is delivery available in Brisbane, the Gold Coast, Sydney and Melbourne?
Selected metropolitan delivery areas may be serviced, but availability, cost and timing depend on postcode and product logistics. Confirm delivery before ordering.
What is the storage capacity?
The tank stores 135 litres of hot water.
What is the first-hour delivery?
Rinnai lists 209 litres in the first hour under its stated test conditions. This includes stored hot water and recovery as water is used.
What is the heating recovery rate?
Rinnai lists 74 litres per hour for a 45°C water temperature rise under its brochure test conditions.
What is its gas rating?
The Hotflo 135L is rated 4.7 stars under the relevant gas energy rating system.
How much natural gas does it consume?
The GHF4135N has a listed maximum gas consumption of 17 MJ per hour. Actual consumption depends on demand and operating time.
Can this unit be connected to LPG?
No. This is the natural gas variant. For bottled LPG applications, a properly selected LPG model is required. Gas type must be verified by a licensed gas fitter.
Can the heater be installed indoors?
No. Rinnai specifies external installation only, with applicable outdoor flue and service clearances.
What size is the unit?
Rinnai lists 1579mm overall height, 420mm width and 508mm depth. Allow additional room for valves, service access and required flue clearances.
How much does the heater weigh?
The manufacturer lists an empty weight of 68kg. Handling and supporting surfaces must accommodate the unit when full of water.
What gas and water connection sizes are specified?
Rinnai lists Rp 1/2 (15mm) gas connection and Rp 3/4 (20mm) water connections. A licensed installer should verify actual pipework requirements.
What water pressure limits apply?
Rinnai specifies a maximum of 680kPa with an expansion control valve and 800kPa without one, with a 1000kPa pressure-temperature relief valve. A licensed plumber must select compliant pressure controls.
Does it have corrosion protection?
Yes. The steel tank has vitreous enamel lining and a sacrificial anode. Service needs depend on water chemistry and the manufacturer instructions.
What servicing does Rinnai recommend?
Rinnai recommends authorised servicing of safety valves and anodes at approximately five-year intervals, with shorter intervals in some harsher water conditions. Follow the supplied installation and service manual.
Is this model suitable for a four- or five-person household?
Rinnai lists up to five people in warmer climates and up to four in cooler climates under its sizing assumptions. Shower duration, flow rates and daily usage can change suitability.
Is the Rinnai Hotflo 170L a better option?
The 170L model has higher storage and first-hour output (170L and 257L respectively). Consider household usage, available space and compatible gas services before choosing.
Does the heater deliver mains-pressure water?
It is a mains-pressure storage design. Actual flow and pressure at taps depend on property pipework, available mains pressure and simultaneous fixture use.
What is the eight-year cylinder warranty?
For qualifying domestic applications, Rinnai includes a one-year comprehensive parts-and-labour warranty and guarantees a replacement unit for an eligible inner-cylinder failure in years two to eight. Replacement labour, transport and installation are the owner’s responsibility during the extended period.
Does the eight-year guarantee cover rental or commercial applications?
Application classifications vary under Rinnai’s definitions: some accommodation uses are defined as domestic while certain centralised and business uses are commercial. Commercial use has different coverage; review the complete warranty before relying on an eight-year guarantee.
Do I need a licensed gas fitter?
Yes. Gas appliance installation, commissioning, alteration and removal must be completed by appropriately licensed or authorised professionals under the applicable regulations and manufacturer instructions.
Should I check the gas type before ordering?
Yes. Confirm your property has natural gas, your current appliance rating plate and the selected replacement model code GHF4135N before purchasing.
Is stock or next-day delivery guaranteed?
No. Stock, delivery availability and lead times are subject to confirmation for your postcode and the chosen model.
Buy Rinnai Hotflo 135L Natural Gas – Supply Only
Order the GHF4135N natural gas storage water heater through Hot Water Outlet and confirm delivery availability for your postcode. Arrange installation separately with an appropriately licensed gas fitter, or ask whether HWO can assist with independent quote requests in your area.
Before ordering: confirm natural gas availability, model code, outdoor installation space, suitable existing connections and any required additional fittings.
Manufacturer source references: Rinnai Hotflo 135L product page · Rinnai gas storage technical brochure · Rinnai gas storage operation and installation manual, including warranty.
*Manufacturer warranty is subject to the full terms and conditions. Product data is not a substitute for the installation manual; specifications and product versions may change. Supply only: Hot Water Outlet does not directly perform installation.
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.
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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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