For instant gas continuous flow hot water installations with non-standard pipework, gas supply upgrades, LPG or natural gas requirements, tight access, relocation work, electrical power point requirements, or uncertainty around the correct unit size, our team can confirm the best option before you book.
🏷️ Brand: Thermann
🔢 Model Number:
📦 Volume: 21L
📏 Width: 338 mm
📐 Height: 520 mm
🌍 Manufactured In: China
🛠️ Heat Exchange Material:
🛡️ Cylinder/Heat-Exchange Warranty: 10 Years
🔇 Noise Level: dBa
⚖️ Dry Weight: kg
📡 WiFi Controller: No
⏲️ Built-In Timer: No
💡 LED/LCD Status Indicator: No
📊 Coefficient of Performance (COP):
⚡ Energy Source:
IMPORTANT - Default supply is Natural Gas — please leave a note at checkout if LPG is required where available.
The Thermann 21R Continuous Flow is a gas continuous flow hot water system designed for homes wanting efficient, on-demand hot water without a storage tank. It is a practical option for buyers comparing Thermann 21R installed pricing, Thermann 21R supply and install, or hot water replacement in Brisbane. Like any gas continuous flow hot water system, the right result depends not just on the unit itself, but on whether the installation suits the home, gas supply, pipework layout, and actual hot water demand.
The Thermann 21R Continuous Flow is a gas continuous flow hot water system, which means it heats water on demand as it passes through the unit rather than storing heated water in a tank. It is a 21L per minute class unit designed for homes wanting stronger hot water delivery than a smaller 17L model while still keeping a compact footprint.
This model is part of the Thermann R-Series continuous flow range and is available in both natural gas and LPG, with both 50°C and 60°C options. It is designed for external installation only and is not designed for commercial use.
One of the main reasons people choose the Thermann 21R Continuous Flow is because it offers continuous hot water only when needed, rather than storing and reheating water throughout the day. That makes it a practical option for households wanting lower running costs and better day-to-day efficiency than an older storage-style system.
This model also suits buyers wanting a compact but stronger-performing unit for smaller to medium homes. It is rated for 2 to 3 outlets, has a 6.1 star energy rating, and is built with a small wall-mounted footprint. Controllers can also be installed for accurate temperature delivery where needed.
The Thermann 21R Continuous Flow is generally best suited to homes with light to moderate hot water demand. It is a strong option where more capacity is needed than a 17L unit can comfortably provide, but where a larger 26L or 32L unit may be more than the property actually needs.
Because this is a gas continuous flow hot water system, installation suitability depends on more than just wall space. Gas supply capacity, water pressure, pipe sizing, clearances, electrical supply, and the final mounting location all matter. This model has dimensions of about 170mm deep, 350mm wide, and 520mm high, with a dry weight of about 15kg.
Final installation scope depends on what is already at the property. Some jobs are straightforward replacements, while others may require extra works. Depending on the site, that may include gas line upgrades, valve changes, tempering, pressure control, power connection, or relocation of the unit to a more suitable position.
A cheaper hot water system is not always the better result once installation suitability, efficiency, reliability, and actual household demand are properly considered. With gas continuous flow systems especially, choosing purely on price can lead to undersizing, disappointing performance, or extra upgrade costs later.
The Thermann 21R Continuous Flow is a purpose-built gas continuous flow hot water system designed for compact installation and reliable on-demand hot water in lighter to moderate-demand settings. Its small wall-mounted footprint, continuous heating operation, controller compatibility, and practical sizing for 2 to 3 outlets all help make it a strong option when matched correctly to the property.
That is why JR Gas & Water focuses on the right product and the right installation together, rather than treating hot water replacement like a one-size-fits-all job.
JR Gas & Water provides professional Thermann 21R Continuous Flow installation in Brisbane & Gold Coast, with the installation assessed around the home’s existing hot water setup, gas supply, plumbing layout, available mounting location, and actual hot water demand. Whether it is a hot water replacement in Brisbane or hot water installation on the Gold Coast, the goal is to make sure the system fits the property properly rather than simply swapping one unit for another.
We also service surrounding areas including Logan, Ipswich, Moreton Bay and Redlands. Our approach is practical and installation-led. That means checking whether the gas supply is suitable, whether the home’s usage matches a 21L continuous flow system, and what may need to change to complete the installation safely and compliantly.
Installing the Thermann 21R Continuous Flow involves more than mounting a compact unit on a wall. Because it is a gas continuous flow hot water system, the installation needs to account for gas supply capacity, hot and cold water pipe connections, safe clearances, commissioning, and how the system suits the expected demand at the property.
In a standard installation scenario, the work may include removal of the old hot water system where applicable, mounting the new unit, connecting hot and cold water pipework, completing the gas connection, connecting power, commissioning the unit, and testing operation. Depending on the site, that may also include gas upgrades, valve changes, tempering requirements, pressure control items, or changes to suit the selected mounting position.
This model has a nominal gas consumption of 159MJ/h, a minimum ignition flow rate of 2.5L/min, and a minimum water pressure of 200kPa. Those details matter when checking whether the home is properly suited to the unit.
JR Gas & Water is installation-led, which matters when you are choosing a gas continuous flow hot water system. The real result depends on whether the system suits the home, the gas supply, the plumbing layout, the mounting location, and the way hot water is actually used in the property.
We work with real homes across Brisbane and the Gold Coast, helping customers choose the right setup for their site rather than relying on generic brochure claims. With a model like the Thermann 21R Continuous Flow, that means practical advice, realistic installation assessment, and a stronger focus on whether the unit is the right fit for the expected demand and available services.
Installation cost depends on what is already at the property. A straightforward replacement in a suitable external location with an adequate gas supply is usually simpler than a job needing gas upgrades, plumbing changes, or relocation. Final pricing depends on the site, access, and what is required for a safe and compliant installation.
It can be a strong option for homes wanting a gas continuous flow hot water system for light to moderate demand. It is generally best suited to properties needing hot water across 2 to 3 outlets rather than heavier family demand.
A standard installation typically includes the core labour and materials needed to install the new unit in a suitable external location and connect it to existing services where conditions allow. That may include mounting the unit, plumbing connections, gas connection, power connection, commissioning, and operational checks. Extra works may still be required depending on the site.
This model has a 12 year heat exchanger warranty and 3 year parts and labour warranty for single family dwellings. For other applications, the warranty is 1 year on the heat exchanger and 1 year parts and labour.
JR Gas & Water installs the Thermann 21R Continuous Flow across Brisbane and the Gold Coast, and also services Logan, Ipswich, Moreton Bay and Redlands. Availability depends on the job type, timing, and site conditions, but we regularly handle gas continuous flow hot water installation across these areas.
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Choosing the right instant gas hot water system package depends on your current setup, whether plumbing or gas upgrades are needed, and if any relocation or compliance work is required. Use this guide to compare package levels and find the best match for your home.
We know things don’t always go to plan — and most customers aren’t plumbers — so we’re flexible and happy to adjust your installation package if needed.
IMPORTANT: All online packages are for EXTERNAL installations only. For internal installations, please request a quote.
✅ Base – For compliant replacements of existing identical EXTERNAL instant systems
Best for like-for-like swaps where the existing system is fully compliant and the same make/model/series. No gas line changes, electrical work, or plumbing alterations.
🧰 Example: Replacing a Rinnai B26 with a Rinnai B26 on the same wall with compliant gas supply.
✅ Silver – For minor upgrades
Includes small plumbing adjustments and a new valve kit. No gas line modifications or system disposal. Designed for customers on a budget upgrading to a slightly different model.
🧰 Example: Replacing a Rheem 26 with a Rinnai B26 where the gas line is compliant but pipework needs modifying to suit and valves need replacing for warranty.
🏆 Gold – Best Seller – For standard installations
Covers everything needed for a standard upgrade: removal of old unit, plumbing changes, valves, and a tempering valve.
🧰 Example: Upgrading from an old Bosch 16P Instant to a new Bosch 16H that requires a tempering valve, with full plumbing refresh and removal of old unit.
💰 Sapphire – Best Value – For installations requiring gas upgrades
Everything in the Gold package plus gas line upgrades or a new gas main from meter to unit to ensure safe and compliant installation.
🧰 Example: Switching from a smaller capacity like a 13L to a larger 26L instant system that needs a larger gas main and full plumbing setup.
✅ Diamond – For major gas plumbing overhauls
Adds extended gas runs, upgraded regulators or meter connections and a new power point. Ideal for homes switching to gas or where old systems were severely non-compliant.
🧰 Example: Changing from electric to gas in a home with no current gas line in the right location, requiring a full line upgrade.
✅ Platinum – The ultimate package
Includes everything: relocation, extensive plumbing, and full gas installation or rerouting. Ideal for complex installs or new system placements.
🧰 Example: Moving the hot water system to the opposite side of the home and running a new gas line with full setup and all compliance.
Here’s your revised Package Comparison Guide with the new line added as the third row, directly under “Existing System Must Be Same Type & Location”:
| Feature | Base | Silver | Gold 🏆 | Sapphire 💰 | Diamond | Platinum |
|---|---|---|---|---|---|---|
| ✅ Existing System Must Be Identical Make/Model as Purchase with Compliant Installation | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ |
| ⚠️ Includes gas supply upgrade to suit larger capacity unit (e.g. 16L replaced with 16L or larger) | ❌ | ❌ | ❌ | ✅ | ❌ | ✅ |
| ✅ Existing System Removal & Form 4 (Compliance Certificate) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| 🔧 Pipework Alterations | ❌ | ✅ | ✅ | ✅ | ✅ | ✅ |
| 🔧 Valve Kit | ❌ | ✅ | ✅ | ✅ | ✅ | ✅ |
| 📏 Pipework Included (m) | ❌ | 2m | 4m | 14m | 4m | 24m |
| 🧱 Support Base (if ground is soft/uneven) | ❌ | ❌ | ✅ | ✅ | ✅ | ✅ |
| 🗑️ FREE Old System Disposal (EXCLUDES ANY AND ALL ROOF MOUNTED COMPONENTS) | ❌ | ❌ | ✅ | ✅ | ✅ | ✅ |
| 🔧 Powerpoint | ❌ | ❌ | ❌ | ✅ | ✅ | ✅ |
| 🔥 Gas Line Upgrade / New Gas Main | ❌ | ❌ | ❌ | ✅ | ❌ | ✅ |
| 📦 System Relocation | ❌ | ❌ | ❌ | ❌ | ❌ | ✅ |
| ✅ Requires Compliant Existing Install | ✅ | ✅ | ❌ | ❌ | ❌ | ❌ |
We only use high-grade parts from reputable manufacturers:
Valves – AVG, RMC, Rye Metal
Copper Pipe – Kembla Type B, Crane
PEX Plumbing – Ezipex
Insulation – eFlex, K-Flex
Brassware – Brasshards
Gas Components – Bromic, EziPress, Viega
Sealants – Loxeal
Let us know if you have any specific brands or components you’d like us to use.
Still unsure which package is right for your home?
The JR Gas & Water team is here to help.
ZipPay allows you to buy now and pay later, offering flexible, interest-free payments for up to 6 months on all JR products. It’s easy to set up, and you can customize your repayment schedule to suit your budget. Payments can be made weekly, fortnightly, or monthly, with a $6 fee if the balance isn’t paid off by the due date.
Humm provides interest-free payment plans on purchases up to $30,000, perfect for both small and large buys. For items over $2,000, you can spread payments over 12 months. Humm also offers flexibility in scheduling payments based on when you get paid
With Afterpay, spread the cost of purchases across four equal installments, due every two weeks, over an 8-week period. There’s no interest, and as long as payments are made on time, there are no fees. Perfect for purchases between $100 and $1,500
Plenti Finance is available exclusively for Reclaim Energy systems. This option offers tailored repayment terms with competitive interest rates, helping make eco-friendly choices more affordable. For more detailed information on Plenti’s terms and eligibility for Reclaim systems, visit the Reclaim Energy finance page
If you're in Queensland and considering a new electric hot water system, JR Gas & Water is the company to choose. Here's why:
Experience and Expertise: JR Gas & Water has over 10 years of experience in the gas and plumbing industry. Their team of licensed and insured professionals is highly skilled and knowledgeable about all aspects of electric hot water system installation, maintenance, and repair. They can provide expert advice on the best system for your needs and ensure a smooth installation process.
Quality Products: JR Gas & Water uses only high-quality products from trusted brands to ensure your electric hot water system is reliable and efficient. They also offer a range of options to suit different budgets and requirements.
Competitive Pricing: JR Gas & Water offers competitive pricing for their electric hot water systems, ensuring that you get a great value for your investment. They also provide a detailed quote upfront, so there are no surprises or hidden costs.
Customer Service: JR Gas & Water is committed to providing excellent customer service. They are always available to answer any questions or concerns you may have and are committed to ensuring your satisfaction.
Local Business: JR Gas & Water is a locally owned and operated business in Queensland. By choosing them for your electric hot water installation, you are supporting a local business and contributing to the local economy.
Warranty and Guarantee: JR Gas & Water provides a warranty and guarantee on all their products and services, giving you peace of mind knowing that your system is covered in case of any issues.
Energy Efficiency: Electric hot water systems can be energy efficient, and JR Gas & Water can help you choose the right system for your needs. They can provide advice on energy-saving features and options, such as timers and thermostats, to help you save on your energy bills.
Safety: JR Gas & Water is committed to safety and ensuring that all installations are done to the highest safety standards. They are also familiar with local safety regulations and requirements, ensuring that your electric hot water system is installed safely and in compliance with all relevant codes.
JR Gas & Water is a reliable and experienced choice for your electric hot water system installation in Queensland. With a commitment to quality products, competitive pricing, excellent customer service, and safety, they can help you make the switch to a more efficient and cost-effective solution for your hot water needs. Contact them today to learn more about their services and how they can help you.
