Combi Boiler Services Calgary
Combi Boiler Installation & Repair in Calgary
Heating and hot water from a single wall-mounted unit — no separate hot water tank, no wasted space. DHL Mechanical installs, repairs, and services combi boilers sized specifically for Calgary's cold groundwater and long heating season.
Combi Boiler at a Glance
What Is a Combi Boiler & Why Is It Popular in Calgary?
A combi (combination) boiler is a single wall-mounted unit that provides both space heating and domestic hot water on demand — without a separate hot water tank. When you turn on a tap, the boiler instantly switches from heating mode to hot water mode, heating cold water directly as it flows through the unit.
Combi boilers are the fastest-growing boiler type in Calgary for good reason: they're compact enough to fit in a utility closet, eliminate the floor space a hot water tank occupies, and deliver 95%+ AFUE efficiency. They're particularly popular in condos, townhouses, and homes under 2,000 sq ft where space is limited and hot water demand is moderate.
The critical factor in Calgary is proper sizing for cold groundwater. Incoming water temperatures drop to 3–4°C in winter, requiring the boiler to raise water temperature by roughly 50°C to reach a comfortable tap temperature. A combi sized for milder climates will underperform in Calgary. DHL Mechanical calculates the actual flow rate you'll get at Calgary winter conditions — not the manufacturer's headline number.
Why Sizing Matters in Calgary
Manufacturers publish flow rates at a 25–35°C rise. In Calgary's winter, you need a 50°C+ rise — cutting the published flow rate nearly in half. We size based on real Calgary conditions to prevent lukewarm water complaints.
Combi Boiler: Great Fit or Wrong System?
A combi boiler is an excellent system — for the right home. Here's how to know if it's the right choice for yours.
A Combi Boiler Is Right If…
- Home is under 2,000 sq ft
- 1–2 bathrooms with standard fixtures
- Condo, townhouse, or small bungalow
- You want to eliminate a hot water tank
- You need both heating + hot water
- You want radiant floor heating + DHW from one unit
A Combi Boiler May Not Be Right If…
- Home is over 2,500 sq ft with high heat load
- 3+ bathrooms or a large soaker tub
- Multiple people shower simultaneously
- You run a dishwasher during showers
- You only need hot water (furnace handles heat)
For larger homes, a system boiler with indirect tank provides higher hot water output. Need hot water only? A tankless water heater is the right choice.
Combi Boiler Services
DHL Mechanical provides complete combi boiler service — from new installations and system conversions to annual maintenance and emergency repair.
- New Installation — Heat-loss calculation, unit selection, all venting, gas piping, magnetic filter, permits, old system removal, and commissioning.
- Tank-to-Combi Conversion — Replacing a conventional boiler + hot water tank with a single combi unit. Includes all piping modifications and disposal.
- Repair & Diagnostics — Diverter valve, flow sensor, plate heat exchanger, ignition, control board, and all other combi-specific repairs. Same-day dispatch.
- Annual Maintenance — Heat exchanger descaling, plate heat exchanger flush, combustion analysis, condensate inspection, and safety check. Required for warranty compliance.
Combi Boiler Pricing Guide
| Service | Typical Range |
|---|---|
| New combi boiler installation | $7,500 – $10,500 |
| Tank-to-combi conversion | $8,500 – $11,500 |
| Annual maintenance / descaling | $180 – $280 |
| Diagnostic & repair | From $180 + parts |
| Diverter valve replacement | $300 – $500 |
| Plate heat exchanger replacement | $400 – $700 |
All prices include labour, materials, and applicable permits. Exact pricing provided after assessment.
Combi Boiler Brands We Install in Calgary
Unlike UK-based guides that recommend Worcester, Vaillant, or Baxi (brands not available in Canada), DHL Mechanical installs brands that are actually sold, supported, and stocked in Alberta. These are the combi boilers we recommend based on real-world performance in Calgary's climate.
IBC
Stainless steel fire-tube heat exchanger. Excellent hard-water tolerance. Strong cold-climate performance. Canadian-made.
NTI
Compact, high-BTU output for its size. Stainless steel heat exchanger. Strong warranty and local parts availability.
Navien NCB Series
Built-in recirculation pump eliminates cold water sandwich. Great value. Dual stainless steel heat exchangers handle hard water.
Viessmann
Premium German engineering. Vitodens 100-W is one of the most efficient combis available. Inox-Radial heat exchanger.
See our full brand comparison guide for detailed breakdowns, or Viessmann vs. NTI head-to-head.
Combi vs. System Boiler vs. Tankless
- Combi boiler — heating + hot water from one unit. Best for smaller homes. $7,500–$10,500.
- System boiler + indirect tank — heating + high-volume hot water. Best for larger homes. $9,000–$14,000+.
- Tankless water heater — hot water only (no heating). For homes with furnaces. $3,500–$6,500.
Not sure which system is right? Call us — we'll assess your home and recommend the right fit.
Combi Boiler Questions
The most common questions Calgary homeowners ask about combination boilers.
A professionally installed combi boiler in Calgary typically costs $7,500–$10,500, depending on the unit and installation complexity. This includes the boiler, old system removal, venting, gas piping, magnetic dirt filter, permits, and commissioning. Converting from a conventional boiler + tank to a combi may add $500–$1,500 for piping modifications.
A combi boiler is ideal for smaller to mid-sized homes (under 2,000 sq ft) with 1–2 bathrooms and moderate hot water demand. If you have 3+ bathrooms, a soaker tub, or multiple people showering simultaneously, a system boiler with an indirect tank is a better choice. Combi boilers heat water on demand and can only supply one major hot water fixture at a time in Calgary's cold groundwater conditions.
Yes, but sizing is critical. Calgary's groundwater drops to 3–4°C in winter, requiring the boiler to raise temperature by approximately 50°C for domestic hot water. This reduces flow rate significantly compared to manufacturer specs at warmer inlets. DHL Mechanical sizes every installation for Calgary's actual winter conditions.
We most commonly install IBC (Canadian-made, stainless steel, hard-water tolerant), NTI (compact, high output, strong warranty), Navien NCB (built-in recirc pump, great value), and Viessmann Vitodens (premium efficiency). The right brand depends on your home's size, hot water demand, and budget.
A tankless water heater provides hot water only. A combi boiler provides both hot water and space heating (radiators, baseboard, or radiant floor heating) from one unit. If your home has a furnace and you only need hot water, go tankless. If you need hydronic heating plus hot water, go combi.
Annual maintenance is required for warranty compliance and safe operation. Calgary's hard water (11–15 grains/gallon) makes annual descaling of the plate heat exchanger especially important. Our service includes heat exchanger cleaning, combustion analysis, condensate inspection, and a full safety check.
Yes — it's one of the most common configurations. Combi boilers are well-suited for radiant floors because radiant systems operate at low water temperatures (30–45°C) where condensing combis achieve peak efficiency. For smaller homes, a combi powering radiant floors while also providing domestic hot water is an excellent, space-saving setup.