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The Rinnai I-Series Plus IP150199C delivers 150,000 BTU of heating power and 199,000 BTU of high-demand domestic hot water in one compact unit. Perfect for larger properties and high-demand households.
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Big home comfort without the big utility bill. Larger homes often struggle with efficient heating, relying on massive, wasteful boilers. The Rinnai I-Series Plus IP150199C is the solution.
Engineered for performance, this unit steps up the heating capacity to 150,000 BTU, ensuring consistent warmth even in spacious properties during the harshest Canadian winters. Yet, it retains the compact, space-saving design of a modern combi unit. With a 96% AFUE rating, it captures heat that older systems waste, turning 96 cents of every dollar spent on gas directly into comfort.
Warranty: Heat Exchanger: 15 Years (Residential Applications) - Parts: 5 Years - Labor: 1 Year (Standard Rinnai Coverage)
Is this the right unit for your home? The IP150199C with 150,000 BTU heating is designed for homeowners who need that extra punch of heating power without sacrificing hot water performance.
Home Sizing: Ideally suited for larger homes up to 3,500 sq. ft.
Heating Versatility: This high-output unit handles complex zones effortlessly:
Large Air Handlers: Capable of supplying multiple air handlers or hybrid systems (mixing air handlers and in-floor heating), providing the high BTU output needed to maintain temperature across all zones.
Extensive In-Floor Heating: Capable of driving heat through larger hydronic floor loops in basements or main floors, including multi-zone systems or applications mixed with other heating methods.
Cast Iron Radiators: Compatible with any type of radiator, including cast iron, baseboard, aluminum, and multi-zone systems.
Important Note for Cast Iron Systems: If you are connecting to an old cast iron radiator system, specific protection devices are required to shield the new boiler from corrosion and dirt.
Enjoy luxury hot water performance without a tank.
Capacity: 199,000 BTU dedicated to hot water means you can run 3+ showers simultaneously.
Flow Rates:
Max Flow: Up to 9.8 Gallons Per Minute (GPM).
Real-World Output: Delivers a robust 5.1 GPM at a 70°F temperature rise, ensuring reliable hot water even when groundwater is freezing cold.
High Demand Options: Ideal for homes with luxury master suites, soaking tubs, or high-flow rain showers. Can be paired with a buffer tank for extreme demands.
Proudly Local: We are based in and proudly serve the Greater Toronto Area and Southern Ontario.
15+ Years of Experience: We have specialized in Boiler and Tankless systems for over 15 years. We aren't generalists; we are experts.
High-Quality Installation Materials: We don't cut corners. We use premium piping, valves, and fittings to ensure your system is leak-free and built to last.
Transparent Pricing: No hidden fees or surprise upcharges. We provide clear, upfront quotes so you know exactly what you are paying for.
Guaranteed Satisfaction: We stand behind our work with a 100% Customer Satisfaction Warranty and a 30-Day Return Policy for your peace of mind.
Fully Certified & Insured: Our technicians are fully licensed and insured, protecting you and your home throughout the installation process.
Rinnai Parts & Repair Availability: We provide comprehensive after-sales support, including full access to genuine Rinnai parts and expert repair services, so you are never left without heat or hot water.
From your first call to final start-up, 4Most Energy certified boiler experts handle everything
We install the new high-efficiency boiler on a secure plywood mounting board and connect it to the gas, venting, and hydronic system. Dual PVC vent pipes (intake and exhaust) are routed through the side wall for proper airflow. The installation also includes setting up a drain system for condensate management and installing all the necessary devices and piping to ensure safe operation. After installation, we perform a full leak test and air bleeding process to remove trapped air and verify system pressure. All connections meet Ontario safety standards, and the system is purged, pressure-tested, and fully optimized for performance.
Complete installation package with all required components.
Enhance your boiler’s efficiency, comfort, and reliability with professional upgrades by 4Most Energy.
| Feature | Specification |
|---|---|
| Model | IP150199C (I-Series Plus) |
| System Type | Combi Boiler (Space Heating + Domestic Hot Water) |
| Rec. Home Size | Up to 3,500 Sq. Ft. |
| Heating Input | 15,000 - 150,000 BTU/h |
| DHW Input | 15,000 - 199,000 BTU/h |
| Flow Rate (70°F Rise) | 5.1 GPM |
| Max Flow Rate | 9.8 GPM |
| Efficiency (AFUE) | 96% (Energy Star Most Efficient) |
| Fuel Type | Natural Gas or Propane (Field Convertible) |
| Dimensions | 18.5" W x 29.1" H x 11.4" D |
We perform proper sizing based on the number of bathrooms, fixtures, gas line capacity, venting, and your home's heat loss. This ensures the Rinnai Combi Boiler is the perfect match for your needs.
We handle the safe disconnection, draining, removal, and eco-friendly disposal of your old boiler, tankless unit, or hot water tank.
Includes professional wall preparation, mounting brackets, clearance verification, and setup for optimal servicing and performance.
We install new PVC/CPVC/S636 venting, upgrade gas lines if needed, set up fresh air intake, and ensure proper condensate drainage with a neutralizer.
We install new isolation valves, clean hot/cold domestic connections, and professionally configure the piping to integrate with your specific heating system (Air Handler, Rads, or In-Floor).
A critical step for safety: We perform gas/water leak checks, startup diagnostics, combustion analysis, flow rate adjustments, and temperature calibration.
We leave the work area spotless, remove all old equipment, provide full homeowner training on the new system, and register the warranty under your name.
When installed by a 4Most Energy certified technician, your Rinnai I-Series Plus includes industry-leading coverage:
We go beyond the manufacturer's warranty to ensure your complete peace of mind:
To keep your warranty valid and your efficiency at 96%, Rinnai recommends professional maintenance. We suggest scheduling this before the heating season to ensure you have smooth, uninterrupted comfort all winter.
At 4Most Energy, we proudly provide professional HVAC, Boiler, Tankless, Furnace & Heat Pump installation across the Greater Toronto Area and Southern Ontario.
Greater Toronto Area: Toronto, Mississauga, Brampton, Markham, Vaughan, Richmond Hill, Aurora, Newmarket, Scarborough.
Extended Service Area: Stouffville, Oshawa, Barrie, Orangeville, Hamilton, St. Catharines, Guelph, Kitchener.
Our certified technicians offer fast response, transparent pricing, and warranty-backed installation wherever you are.
A Rinnai Combi (Combination) Boiler is a single, compact unit that handles two major jobs for your home:
Central Heating: It heats the water that circulates through your Air handler, Furnace, radiators or radiant floor heating system.
Domestic Hot Water (DHW): It acts as a tankless water heater, providing continuous hot water for showers, taps, and appliances.
Unlike traditional systems that require a massive boiler plus a separate hot water storage tank, the Rinnai I-Series (and M-Series) does it all in a wall-mounted unit roughly the size of a suitcase.
A Heat-Only boiler (like the Rinnai I-Series Heating models) is a dedicated engine for warming your home via radiators or in-floor loops. It does not produce tap water directly. A Combi boiler does both jobs (heating + hot water) in one box. You should choose a Heat-Only model if you have a large home with high hot water demand and prefer using a separate Indirect Hot Water Tank for better volume.
One of the biggest advantages of the Rinnai I-Series Plus is its ability to deliver simultaneous home heating and hot water.
The Problem with Older Combis: Traditional combi boilers often prioritize hot water. If someone takes a shower, the house heating pauses.
The Rinnai Solution: The I-Series uses advanced logic to maintain your home's temperature while ensuring your shower stays hot. It essentially multitasks, ensuring comfort isn't compromised during high-demand times like morning routines.
Yes, in two significant ways:
Energy Efficiency: Rinnai Combi Boilers are condensing units with up to 96% AFUE (Annual Fuel Utilization Efficiency). This means for every dollar you spend on natural gas, 96 cents goes directly into heating your home and water. Older boilers often operate at 60-80% efficiency.
Space Savings: By eliminating the hot water tank, you free up roughly 12-16 square feet of floor space—valuable real estate in Toronto condos and townhomes.
The Rinnai I-Series features a Self-Cleaning Stainless Steel Heat Exchanger.
Design: Unlike competitors that use aluminum (which can corrode) or standard stainless steel, Rinnai uses a unique down-fired ceramic burner design.
Self-Cleaning Action: By firing downwards, condensation naturally drains out of the unit, flushing away sediment and preventing mineral buildup on the heat exchanger walls. This design significantly extends the lifespan of the unit compared to traditional up-fired boilers.
The down-fired ceramic burner is a key design element of the Rinnai I-Series.
Vertical Integration: The burner is located at the top of the heat exchanger, firing flame downwards. This maximizes heat transfer as the hot gases travel through the stainless steel tubes.
Modulation: The burner design allows for an incredibly high Turndown Ratio (up to 10:1). This means the boiler can run at just 10% of its power on mild Spring days, avoiding the "short-cycling" (turning on and off rapidly) that wears out other boilers.
Yes, absolutely. However, retrofitting a modern high-efficiency boiler to a vintage cast-iron system requires expert design to ensure longevity.
System Design (Primary/Secondary Loop): A boiler expert must design the piping using a primary/secondary loop. This is critical to ensure the correct flow rate through the boiler while maintaining the high-volume circulation required to heat heavy cast-iron radiators evenly.
Boiler Protection (Dirt Collector): Old radiators often contain decades of sludge and sediment. A Dirt Collector (Magnetic Filter) is mandatory to trap this debris before it enters the new boiler, preventing damage to the sensitive heat exchanger.
Air Elimination: It is vital to install an Air Eliminator to scrub oxygen from the water. Oxygen is the primary cause of corrosion in cast-iron systems.
Sizing: As always, the unit must be accurately sized for both the home's heat loss and your domestic hot water demand.
Feel free to get free professional advice from our boiler experts at 4Most Energy, serving the Greater Toronto Area and Southern Ontario.
The Rinnai I-Series offers a maximum flow rate of 9.8 Gallons Per Minute (GPM), providing superior performance compared to other brands. However, capacity depends on seasonal water temperatures:
Performance depends heavily on the model's BTU capacity and seasonal water temperatures:
160,000 BTU Models: These units are specifically designed for small condos and townhouses. They provide less hot water capacity and are recommended for homes with a maximum of 1 shower running at a time.
199,000 BTU Models: These larger units offer a maximum flow rate of 9.8 Gallons Per Minute (GPM). Even in winter, as the inlet water temperature drops, they adjust to approximately 5.1 GPM, which can easily handle two showers simultaneously.
Capacity: Even at this winter rate, the Rinnai can easily handle two showers simultaneously without losing pressure or heat.
Large Home Recommendation: For larger homes with more than two showers, we recommend installing a buffer tank. This addition handles higher demand and provides faster hot water delivery, ensuring peak performance even during the coldest Canadian winter days.
Important: Always ask 4Most Energy boiler experts to calculate the specific temperature rise and domestic hot water flow rate for your home before buying a combi boiler. Incorrect sizing can lead to significant hassles and inadequate hot water.
Yes, absolutely. For Ontario condos, townhouses, and homes where space savings, high capacity, and efficiency are critical, this combination offers the perfect all-in-one solution.
Rinnai Combi Boilers are designed to provide the perfect water temperature to maximize the efficiency of hydronic heating applications. They pair perfectly with:
High-Velocity Systems: Brands like MAX AIR, iFLOW, Spacepak, The Unico System, and Enerzone.
Low-Velocity Systems: Traditional systems from brands like Carrier, Trane, and Lennox.
One-Stop Shop: 4Most Energy is an expert in these integrated heating solutions. We not only specialize in Rinnai Combi Boilers but also supply and install high-performance air handlers, ensuring your entire system is optimized for comfort and efficiency.
Yes, Rinnai Combi Boilers are excellent for these applications, but the system must be designed by an expert to ensure efficiency and prevent damage.
Slab Protection: Precise temperature control is required to prevent the concrete slab from cracking due to thermal shock.
Smart Circulation: A variable speed pump is essential to automatically adjust water circulation based on pipe resistance in different zones.
Hydraulic Separation: For multi-zone systems, using proper manifolds and a Low Loss Header is critical to decouple the boiler flow from the system flow. A bypass loop may also be necessary depending on the setup.
Advanced Sensing: The system should utilize communicating slab sensors and an outdoor reset sensor to modulate heat output according to the actual weather conditions.
Sizing & Capacity: It is most important to calculate the Domestic Hot Water (DHW) demand to choose the right unit. In some cases, a buffer tank is needed to compensate for high demand.
4Most Energy Professional Services: We provide all necessary devices, expert system design, and free consultations for in-floor heating projects.
The Rinnai I-Series is engineered as a superior retrofit solution for replacing older technology or failing combi boilers. It is an ideal, high-efficiency upgrade for homeowners currently using:
Flow Max
Baxi
Viessmann
Bosch
Navien
Older Rinnai models
Get Instant Professional Advice: Feel free to get professional advice right away! Talk with an expert on WhatsApp for free to discuss replacement options for your specific unit.



Our quote is customized based on your current situation or specific new application needs to ensure system optimization. For customers in Toronto, Southern Ontario, and surrounding areas, our comprehensive proposal covers everything required to run the boiler reliably:
Core Installation: Removal/disposal of the old unit and professional installation of the Rinnai boiler with S636 venting.
Essential Hydronic Components: Installation of all critical devices needed to run the boiler, such as the Recirculation Pump, Expansion Tank, Feeder, and Isolation Valves.
System Protection: Inclusion of Air Eliminators or Dirt Collectors to protect the new heat exchanger, plus a full system flush.
Advanced Piping (As Needed): Setup of a Primary/Secondary Loop, and Zone/Pump Controllers depending on your specific application.
Safety & Setup: Post-install gas/CO safety checks, followed by expert programming and balancing.
We follow a strict, safety-first protocol to ensure a smooth upgrade for your home. Here is our step-by-step process:
Site Preparation & Safety: We park safely to avoid blocking your neighbors. Inside, we cover floors and steps with protective runners and organize the boiler room to create a safe workspace for gas and plumbing work.
Removal & Disposal: We carefully drain and disconnect your old unit to prevent any water damage. We then remove it and transport it to a proper dump station—we never leave old equipment on your driveway or curb.
Mounting & Rough-In: We build a sturdy plywood platform on the wall to securely mount the new boiler and support all piping and devices. We use only high-quality fittings and piping.
Safety Precautions: If soldering is required, we temporarily cover smoke detectors to prevent false alarms and take full fire-safety precautions.
Gas & Wiring: We connect the gas lines and perform a preliminary pressure test to ensure no leaks. We then connect all thermostats, zone controllers, and pumps.
Venting (Critical Step): We install System 636 PVC venting with the correct slope to ensure condensation drains back to the unit. We use heavy-duty core bits to drill through your exterior wall, ensuring no damage to bricks or wooden structures.
Commissioning & Testing:
Leak Checks: We fill the system and check for water leaks.
Gas Calibration: We run the boiler for at least one hour, calibrating gas pressure and performing a carbon monoxide (CO) safety analysis.
Joint Inspection: We inspect all joints under heat stress to ensure they don't crack or leak.
Drainage: We verify the high-efficiency condensation drains properly to the floor drain or pump.
Tagging & Handover: Once the system passes all tests, our Gas Technician tags the pipe. We then walk you through the new system, showing you how to adjust temperatures and perform basic maintenance.
Post-Install Support: It is possible for minor adjustments to be needed after a fresh install. As a reputable contractor, we stand behind our work—if you see a leak or issue, we fix it fast (same day or next morning). Finally, we register your unit to officially start your warranty.
Most residential replacements are completed in one day (approx. 6–8 hours). Our team arrives in the morning with all necessary parts and aims to have your heat running by the evening.
The final cost depends entirely on the boiler size, required hydronic items, and heating application. Upgrading from a low-efficiency or older unit is complex; it often requires upgrading plumbing using high-grade materials like copper, stainless steel piping, oxygen-barrier PEX, and premium fittings.
Starting Price: A professional installation by a Master Technician using high-quality materials starts at $2,000 (labor & material). This price increases as the boiler system becomes more complex (e.g., adding zoning or indirect tanks).
The "Cheap Quote" Warning: It is critical to avoid contractors offering suspiciously low prices. A boiler installed incorrectly often doesn't show symptoms right away but can suffer critical damage in less than 4 years. Furthermore, improper installation voids the manufacturer's warranty. Boiler installation requires a specialized Hydronic Expert, not just a general gas technician or plumber.
When installed by a licensed professional like 4Most Energy, the Rinnai I-Series typically comes with industry-leading coverage:
Heat Exchanger: 12 Years
Parts: 5 Years
Labour: 1 Year (Standard)
Extended Labor Warranty Option: You can extend your labor warranty coverage up to 10 years. Ask the 4Most Energy sales department for details on our protection packages.
Understanding Your Coverage:
What "Labor Warranty" Means: If a part covered by the manufacturer's warranty fails, you do not pay for the labor to replace it.
After Warranty Expires: Once the labor warranty period ends, you are responsible for paying the service call fee and the labor cost for replacing any parts.
4Most Energy - Authorized Warranty Support: As an Authorized Rinnai Service Provider, 4Most Energy handles the entire warranty process for our clients. If a defect arises, we can directly claim, supply the parts, and replace the defective items, ensuring a seamless and hassle-free experience for you.
Yes, absolutely. We stand behind our craftsmanship.
The 4Most Energy Installation Guarantee: Beyond the boiler unit itself, 4Most Energy covers installation-related issues for one year after installation. This includes:
Drain line issues
Support and mounting stability
Wiring connections
System calibration
Plumbing connections
We ensure the system is set up perfectly so you don't have to worry about the "small stuff" causing big headaches.
Annual maintenance is strictly recommended to ensure you have smooth heating and hot water during cold weather. It is essential to improve performance, reduce the risk of gas or water leaks, and increase the lifespan of your unit.
Our expert service includes:
Descaling/Flushing: Circulating a solution to remove internal mineral buildup.
Filter Cleaning: Cleaning the air intake filter and the domestic cold water inlet filter.
Ignition Check: Inspecting and cleaning the spark igniter and flame rod.
Safety Check: Verifying there are no gas or exhaust leaks to ensure your family's safety.
Combustion Analysis: Measuring CO and CO2 levels to ensure the unit is burning fuel safely and efficiently.
Some areas of Ontario have moderately hard water.
The Risk: Without regular flushing, calcium and magnesium minerals precipitate out of the water and stick to the inside of the heat exchanger (scale).
The Damage: This scale acts as an insulator, trapping heat in the metal. This causes "thermal stress," leading to premature cracks and leaks in the heat exchanger—damage that is not covered by warranty.
Yes, it can. Warranty coverage is contingent on proper care and use of the unit. Your warranty may be voided due to:
Poor Maintenance: Failures caused by scale buildup or poor water quality are strictly not covered.
Unauthorized Installation: Units must be installed by a licensed professional. DIY or unauthorized installations often void warranty terms.
Improper Usage/Application: Using residential equipment for commercial applications (e.g., in a busy restaurant or hotel) or operating the unit outside of its design specifications.
Lack of Maintenance: Failure to perform annual service can lead to premature failure that manufacturers will not cover.
Regular annual maintenance by an authorized provider is the only way to prove you have cared for the unit, protecting both your investment and your warranty coverage.
We are not just a general HVAC company; we are Authorized Rinnai Hydronic Experts serving homeowners across the Greater Toronto Area and Southern Ontario.
Fair Price & 5-Star Quality: We are not the "cheap guy" who cuts corners, nor are we an overpriced corporation. We offer fair, transparent pricing for high-quality craftsmanship, always striving to earn a 5-Star Review after every job.
Local Stock & Reliability: We stock critical Rinnai parts in our local warehouse. If your heat goes out in January, we minimize downtime from days to hours.
Direct Access to Experts: You deal directly with a Master Technician, not a commission-based salesperson. We design your system correctly from Day 1.
Warranty Guardianship: We handle your unit registration and stand as your advocate with the manufacturer.
4Most Energy customers get priority support. You speak directly to a boiler expert, not a call center. Because we stock genuine Rinnai parts locally, we can often diagnose and fix issues faster than companies that have to wait for shipments.
Yes. We are comprehensive hydronic specialists. We service, repair, and maintain all major makes and models, including:
Viessmann
Flowmax
Baxi
Navien
NTI
And many others. The Rinnai Advantage: While we are experts on all brands, for Rinnai systems specifically, we stock all parts locally. This means if you have a Rinnai boiler, we can typically solve your issue on the very first visit without waiting for parts to ship.
Yes. We offer flexible payment plans, including 3 Months No Payments/No Interest or low monthly payments for up to 24 months, helping you upgrade to high-efficiency comfort without the upfront stress.
Yes. We offer a "Supply Only" service. We provide the full kit (Boiler + Venting + Valve Kits) and offer free sizing consultation to ensure you buy the right model. We also provide technical support if you get stuck during your install.
Live Chat via WhatsApp. We offer free consultation and troubleshooting directly through WhatsApp. You can send us photos of your current setup, and a Master Technician (not a sales rep) will provide a rough estimate or technical advice instantly.
Posted on FoadTrustindex verifies that the original source of the review is Google. Excellent service at a very reasonable price! The team was professional, efficient, and really went above and beyond to make sure everything was done right. I’m very happy I found them—working with people who truly care about their customers makes all the difference. I wouldn’t hesitate to recommend their services to anyone looking for great quality and value.Posted on Eddy LeeTrustindex verifies that the original source of the review is Google. Fantastic service. On a Friday (before a long weekend and with a planned pool party) I noticed my pool heater was not working and have an ignition error. I called up 4Most Energy and they had someone out there that same day at 7PM to diagnose and fix the issue. Great prompt service!Posted on E LTrustindex verifies that the original source of the review is Google. Rey and his technician were prompt, knowledgeable and helpful thoughout the process of assessing the heating needs for my pool. My pool heater had gone end of life and they patiently walked me through options and I settled on a new pool heater. He came the next day to install and even optimized the pipping that my pool maintenance company had previously put in. Highly recommend 4Most Energy and Rey.Posted on ness malTrustindex verifies that the original source of the review is Google. 4most energy came to change my furnace. From the onset Ray provided excellent customer service and took the time to explain everything. He was honest and upfront. His team showed up on time and completed the work professionally. Would recommend them for anyone looking to upgrade their furnace.Posted on Vignesh BharadwajTrustindex verifies that the original source of the review is Google. It was a delight to work with 4most Energy from the day I first spoke to Rey over the phone to the day my boiler installation was done. The guy did not compel me to haggle or think twice about anything, whether the cost or the quality of the brand. He was happy to answer my million questions. The day of the installation was just as smooth. The team of two showed up right on time, and finished the job by evening as promised. The guys did an amazing job - very neat work, left the place tidy, took away my old unit and cleaned up everything without a spot on their way out. Really appreciate their professionalism. My full marks to 4most Energy - keep up the great work guys!Posted on Manuel PereiraTrustindex verifies that the original source of the review is Google. The job was great. They were very clean and fast. We are very happy with the service. Thank you!Posted on Matti SaranTrustindex verifies that the original source of the review is Google. Sam and the team were excellent were amazing explained things very well. Thank you so muchPosted on C.J. CroccoTrustindex verifies that the original source of the review is Google. Rey and his team were amazing! They were able to come in and find the issue with my heater. Replaced a week later and works like a charm. They are super knowledge and give you every option to work within your budget.Posted on Sarina TakiTrustindex verifies that the original source of the review is Google. I had an exceptional experience with 4mostenergy for my recent AC installation. From start to finish, the service was top-notch. The team arrived on time, worked efficiently, and the installation was flawless. They were incredibly professional and attentive to every detail, ensuring that everything was set up perfectly. I highly recommend 4MostEnergy for their outstanding service and expertise!Posted on Ivan SingTrustindex verifies that the original source of the review is Google. Attention to detail and friendly service. Honest pricing. Cleaned up after completion of installation. Highly recommend.
Off-season pricing means the best deals of the year on high-efficiency air conditioners.
Save Big on Lennox Furnaces — Limited Time!
Get a new high-efficiency Lennox furnace with no payments for up to 6 months. Premium comfort, top-tier performance.
Simple estimates, flexible payments, pro installation, and industry-leading warranties.