Viessmann Vitodens 100-W B1HE Heat-Only Boiler – Supplied & Professionally Installed by 4Most Energy
The Viessmann Vitodens 100-W B1HE is a wall-mounted, high-efficiency condensing heat-only boiler for residential hydronic space heating. The series is available in four sizes — B1HE-85, B1HE-120, B1HE-150 and B1HE-199 — with maximum inputs from 85,000 to 199,000 BTU/h, so the boiler can be matched to the home's calculated heat loss rather than oversized.
Every model is rated at 95% AFUE and combines Viessmann's Inox-Radial stainless-steel heat exchanger with a modulating MatriX-Plus stainless-steel cylinder burner. On the B1HE-85, -120 and -150, the burner modulates across an approximately 10:1 range, lowering its firing rate when demand drops to reduce short cycling and improve part-load efficiency. The condensing design performs best with low return-water temperatures, such as in radiant in-floor systems.
The B1HE is a heat-only boiler, not a combi. Domestic hot water is provided by pairing it with a properly sized indirect water heater. It can serve radiant in-floor heating, hydronic baseboard, hot-water radiators, multi-zone systems, and air handlers with hydronic coils, and it runs on natural gas or liquid propane, subject to correct setup and commissioning.
Rated efficiency depends on correct installation. Sizing, near-boiler piping, zoning, controls, venting, and condensate management all affect real-world performance. Professional installation addresses heat-loss calculation, gas and hydronic connections, approved venting, condensate drainage, controls setup, and commissioning in line with the manufacturer's instructions and applicable local codes.
Its compact wall-mounted cabinet, quiet operation, and built-in Wi-Fi with ViCare app compatibility (confirmed in supplier data for the B1HE-85 to B1HE-150) make it a practical replacement for older floor-standing boilers.
4Most Energy will assess the home and confirm the correct B1HE size, installation scope, and any required system modifications before work begins. Final sizing should be based on a building heat-loss calculation, not square footage alone.
Why Install the Viessmann B1HE with 4Most Energy?
Key Features of the Viessmann Vitodens 100-W B1HE
- 95% AFUE efficiency condensing technology across all four sizes for efficient fuel use.
- Four sizes from 85,000 to 199,000 BTU/h B1HE-85, B1HE-120, B1HE-150 and B1HE-199 inputs to match a range of calculated heating loads.
- Up to 10:1 modulation on the B1HE-85, -120 and -150, adjusting burner output to demand to reduce short cycling.
- Inox-Radial stainless-steel heat exchanger designed for condensing operation and backed by a 10-year heat exchanger warranty.
- MatriX-Plus stainless-steel cylinder burner fully modulating burner for controlled, efficient combustion.
- Lambda Pro Plus combustion control adapts to natural gas or propane without mechanical adjustment (B1HE-120 supplier data).
- Natural gas or liquid propane dual-fuel capability, subject to correct setup and commissioning.
- Built-in Wi-Fi, 3.5-inch LCD and ViCare app connected monitoring and control, with weather-responsive heating-water temperature adjustment.
- Indirect hot-water ready heat-only design pairs with a properly sized indirect water heater for domestic hot water.
- Compact wall-mounted, quiet design space-saving installation with low sound levels at partial load.
Technical Specifications
| Specification | B1HE-85 | B1HE-120 | B1HE-150 | B1HE-199 |
|---|---|---|---|---|
| Max. input | 85,000 BTU/h | 120,000 BTU/h | 150,000 BTU/h | 199,000 BTU/h |
| Min. input (natural gas) | 8,500 BTU/h | 12,000 BTU/h | 15,500 BTU/h | Confirm with manufacturer data |
| Heating output | Approx. 80,000 BTU/h | Approx. 113,000 BTU/h | Approx. 141,000 BTU/h (DOE) | Approx. 187,000 BTU/h (DOE) |
| Net AHRI rating | 70,000 BTU/h | 98,000 BTU/h | Confirm with manufacturer data | Approx. 163,000 BTU/h |
| AFUE | 95% | 95% | 95% | 95% |
| Modulation | 10:1 | 10:1 | Approx. 10:1 | Wide modulation range |
| Flow rate (GPM) | 4.8 | 6.2 | 8.8 (max. boiler flow) | 10.6 |
| Fuel | Natural gas / LP | Natural gas / LP | Natural gas / LP | Natural gas / LP |
| ENERGY STAR (per supplier listing) | Yes | Yes | Yes | Yes |
Specifications compiled from supplier listings for each model. Heating output and net AHRI ratings differ from maximum input; confirm final
ratings against current Viessmann product data before sizing. Minimum LP input on the B1HE-150 is listed at 22,700 BTU/h.
| Installation & Physical Data | B1HE-85 | B1HE-120 | B1HE-150 | B1HE-199 |
|---|---|---|---|---|
| Dimensions (H × W × D) | 33.75 × 17.75 × 19.75 in. | 33.75 × 17.75 × 19.75 in. | 39 × 17.75 × 21.75 in. | 39 × 17.75 × 21.75 in. |
| Weight | Approx. 108 lb | Approx. 108 lb | Approx. 179 lb | Approx. 179 lb |
| Electrical | 120 VAC / 1 ph / 60 Hz | 120 VAC / 1 ph / 60 Hz | 120 VAC / 1 ph / 60 Hz | 120 VAC / 1 ph / 60 Hz |
| Max. operating pressure | Confirm | 60 PSI | 60 PSI | Confirm |
| Sound level | 52 dB full / 34 dB partial | 59 dB full / 34 dB partial | Not listed | Not listed |
| Heat exchanger | Inox-Radial stainless steel | Inox-Radial stainless steel | Inox-Radial stainless steel | Inox-Radial stainless steel |
| Controls | Wi-Fi, 3.5-in. LCD, ViCare | Wi-Fi, 3.5-in. LCD, ViCare | Wi-Fi, 3.5-in. LCD, ViCare | Smart controls, outdoor reset |
| Mounting | Wall-mounted | Wall-mounted | Wall-mounted | Wall-mounted |
The B1HE is a condensing appliance. Approved vent materials, configuration, diameter, maximum length (up to 180 ft / 60 m listed for the B1HE-150),
clearances, and condensate drainage must follow the manufacturer's installation manual and applicable local codes. Natural gas or propane
setup is confirmed against the exact appliance configuration before installation.
Which Viessmann B1HE Size Is Right for Your Home?
The B1HE series is sized by the home's calculated heat loss, not by matching the old boiler or by square footage alone. Older boilers were often oversized, and an oversized boiler cycles more and loses efficiency.
| Model | Capacity | Typical application (preliminary guidance) |
|---|---|---|
| B1HE-85 | Up to 85,000 BTU/h input | Smaller, medium, and energy-efficient homes with relatively low heat loss |
| B1HE-120 | Up to 120,000 BTU/h input | Typical medium-sized homes with moderate heating loads |
| B1HE-150 | Up to 150,000 BTU/h input | Medium-to-large homes with moderate-to-high heating loads |
| B1HE-199 | Up to 199,000 BTU/h input | Larger homes and high heating loads |
Sizing Considerations
- Heat loss: a room-by-room or whole-home heat-loss calculation sets the required output.
- Distribution: radiant in-floor, baseboard, radiators, and air-handler coils each affect supply temperatures and condensing efficiency.
- Zoning: multi-zone systems benefit from the B1HE's wide modulation range.
- Domestic hot water: if an indirect water heater is added, its demand is included in the selection.
These ranges are preliminary guidance, not manufacturer-rated home sizes. 4Most Energy confirms the final B1HE size with a heat-loss calculation before ordering.
Our Installation Journey
| Phase | Description & Key Requirements | |
|---|---|---|
| Step 1 | Request an Installation Quote | Provide the existing heating system details, property information, and project requirements. |
| Step 2 | System Sizing Consultation | Evaluate building heat loss, existing hydronic distribution, fuel supply, venting, and electrical requirements. |
| Step 3 | Equipment Recommendation | Confirm the correct B1HE size (85, 120, 150 or 199) and whether an indirect water heater or other system changes are needed. |
| Step 4 | Installation Scheduling | Agree on the project scope, equipment availability, site requirements, and installation date. |
| Step 5 | Removal of Existing Equipment | Disconnect and remove the existing boiler and associated equipment where included in the approved quotation. |
| Step 6 | Installation & System Connection | Mount the boiler and complete the specified heating, gas, venting, condensate, electrical, and control connections. |
| Step 7 | Safety & Operational Testing | Check the required safety functions, combustion setup, gas connections, water connections, and system operation. |
| Step 8 | Final Commissioning | Configure the controls, verify heating operation, and explain the system's basic operation to the homeowner. |
What Installation Includes
The exact inclusions depend on the approved quotation. A typical installation scope may include:
- Supply of the specified Viessmann B1HE boiler.
- Removal of existing equipment if expressly included.
- Standard boiler mounting and required system connections.
- Approved venting and condensate arrangements within the quoted scope.
- Connection to existing compatible heating distribution piping.
- Controls setup, testing, and commissioning.
What May Be Excluded
Unless specifically included in writing, additional work may be charged separately for:
- Major gas-line upgrades or meter-related work.
- Electrical service upgrades or new circuits.
- Extensive vent-route modifications or structural alterations.
- Hydronic piping replacement, additional zones, or major system redesign.
- Remediation of existing code violations.
- Water treatment, chimney work, drywall repairs, painting, or other finishing work.
- Permits, inspection fees, or third-party services not included in the quotation.
Payment Process
- Receive and review the written quotation and installation scope.
- Confirm the project schedule and any required deposit.
- Pay according to the agreed payment milestones.
- Settle the remaining balance according to the written terms.
Manufacturer Warranty
| Component | Warranty Period |
|---|---|
| Parts warranty | 5 years |
| Heat exchanger warranty | 10 years |
Coverage depends on appliance registration, installation requirements, application, and current Viessmann warranty documentation. 4Most Energy completes the required start-up documentation to support warranty coverage. 4Most Energy's installation labour warranty terms are provided in writing with your quotation.
Warranty Claim Process
- Contact 4Most Energy with the model, serial number, installation date, and description of the issue.
- Provide proof of purchase and installation records where requested.
- Arrange an inspection or diagnostic visit if required.
- Determine whether the issue falls under manufacturer parts coverage, installer labour coverage, or a separate paid service.
- Submit the applicable claim through the manufacturer's authorized process.
- Complete the approved repair or replacement in accordance with the applicable warranty terms.
Warranty approval, covered expenses, and replacement decisions remain subject to the responsible provider's terms.
Optional Maintenance Plans
Maintenance plans starting from $12.99/month — keep your heating system operating as intended with a maintenance plan tailored to your equipment and service needs. Potential plan benefits, subject to the plan selected, may include:
- Scheduled preventive maintenance.
- Inspection of system operation and safety components.
- Review of boiler controls and operating performance.
- Early identification of service concerns.
- Maintenance records and service reminders.
- Access to plan-specific service benefits.
Annual maintenance should follow the manufacturer's requirements and the installed system's operating conditions. Contact 4Most Energy to confirm current plan pricing, covered services, eligibility, and enrollment terms.
Service Area
Greater Toronto Area (GTA) and surrounding regions
Toronto, Markham, Richmond Hill, Vaughan, Aurora, Newmarket, Scarborough, Brampton, and Mississauga.
Extended Service Area: Stouffville, Oshawa, Barrie, Orangeville, Hamilton, St. Catharines, Guelph, Kitchener.
Frequently Asked Questions
Is the Viessmann B1HE a combi boiler?
No. The B1HE is a heat-only boiler for hydronic space heating. Domestic hot water is provided by pairing it with a properly sized indirect water heater.
Which B1HE size do I need?
It depends on your home's calculated heat loss. The B1HE-85 suits smaller or energy-efficient homes, the B1HE-120 typical medium-sized homes, the B1HE-150 medium-to-large homes, and the B1HE-199 larger homes with high heating loads. 4Most Energy confirms the size with a heat-loss calculation.
How efficient is the Viessmann B1HE?
All four sizes are rated at 95% AFUE. Modulation of up to 10:1 on the B1HE-85, -120 and -150 lets the burner lower its output when demand drops, reducing short cycling.
Can the B1HE run on propane?
Yes. The B1HE is designed for natural gas or liquid propane, subject to correct setup and commissioning. 4Most Energy verifies the fuel configuration before installation.
What heating systems does the B1HE work with?
It can serve radiant in-floor heating, hydronic baseboard, hot-water radiators, multi-zone systems, and air handlers with hydronic coils. It is most efficient in low-temperature systems such as radiant in-floor.
