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Boiler Experts › Boiler Repair Markham

Boiler Repair
Markham — Unionville, Cornell & Berczy

Mazgan Inc. is a G1-licensed, Navien-certified boiler specialist serving all of Markham — Unionville, Cornell, Berczy Village, Milliken, Angus Glen, Cathedraltown, and beyond. Same-day emergency response. Owner-operated. Every brand serviced.

G1 Licensed Navien Certified NTI Certified Same-Day Service Owner-Operated
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Local Boiler Service

Markham Boiler Service — Unionville to Cornell

Markham has one of the most diverse housing mixes in York Region when it comes to boiler work. Historic Unionville has character homes from the 1800s and early 1900s with original or rebuilt heating systems — some still on cast iron radiators. Cornell and Berczy Village are packed with 2000s and 2010s-era builds, many with Navien NCB combi boilers and radiant or hydronic heating. And Angus Glen has custom estate properties with complex multi-zone systems.

We know Markham's water hardness varies by area — Milliken and Buttonville tend to have harder water than the Cornell area, and we account for that in our maintenance recommendations. Annual descaling on Navien units in these harder-water areas is especially important.

  • Boiler repair — no heat, ignition failure, lockout codes Details →
  • Combi boiler repair — no heat, no hot water, diverter valve Details →
  • Navien boiler repair — all error codes, certified technician Details →
  • Radiant floor heat — zone failure, pump, zone valve Details →
  • Glycol testing & flush — protect your heat exchanger Details →
  • Annual maintenance — combustion analysis, full inspection Details →
  • Boiler replacement — all brands, full installation

Neighbourhoods We Service in Markham

We service every Markham community for boiler repair, annual maintenance, and installation.

UnionvilleCornellBerczy VillageMillikenAngus GlenCathedraltownGreensboroughButtonvilleOld Markham VillageWismerBox GroveCornell Rouge
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Owner Does the Work
No subs. The licensed tech who answers is the one who shows up.
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Same-Day Response
No-heat calls get priority. We carry parts for same-visit repairs.
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Navien & NTI Certified
Factory-trained — not just general HVAC experience.

Boiler Emergency in Markham?

Same-day response. G1 licensed. Parts on the truck. Call now and we'll give you an honest ETA.

📞 647-699-2474
FAQ — Markham Boiler Repair

Common Questions from Markham Homeowners

Yes — Unionville is one of our regular service areas. The heritage properties in historic Unionville often have older boiler systems — some original equipment, some replaced with mid-efficiency units in the 90s and 2000s. We service all ages and generations of gas boilers, including older atmospheric units with standing pilots and cast iron heat exchangers.
Yes — factory-certified Navien service technician. Cornell has a high concentration of Navien NCB combi boilers installed in the 2010s that are now entering their first major service cycle. E003, E012, E110, E407 — we diagnose Navien error codes accurately, carry the right parts, and follow Navien's service procedures to keep your warranty intact.
Yes — radiant floor and multi-zone hydronic heating is common in Berczy Village and Angus Glen's larger custom properties. Zone not heating, circulator pump failure, zone valve replacement, glycol testing — all handled. We also service snowmelt systems on driveway aprons in these communities.
Markham's water hardness — particularly in Milliken and Buttonville — accelerates scale buildup inside Navien and NTI heat exchangers. Scale reduces efficiency and causes the boiler to overpressure and fault. We include a heat exchanger inspection and descaling check at every annual maintenance visit in Markham. Annual glycol testing is also important for closed-loop systems.
Yes — all of Markham including Cathedraltown, Greensborough, Wismer, Box Grove, and Cornell Rouge. We don't limit by community — if you're in Markham, we come to you. Same-day emergency service available for no-heat calls throughout Markham.
Free Quote

Get a Quote for Boiler Repair in Markham

Fill out the form and we'll get back to you fast — usually within the hour during business hours. For emergencies, always call directly at 647-699-2474.

  • ✓ G1 Licensed — all gas boiler work in Ontario
  • ✓ Navien & NTI factory certified
  • ✓ All brands — Navien, NTI, Viessmann, Weil-McLain, IBC
  • ✓ Radiant floor, baseboard, combi, multi-zone
  • ✓ Upfront pricing — no surprises

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Free estimate — Markham, Ontario
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More Services

Boiler Services Available in Markham

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Combi Boiler Repair
No heat, no hot water, diverter valve, pressure issues — all combi brands.
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Navien Boiler Repair
Factory-certified Navien service — error codes, sensors, heat exchangers.
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Radiant Heating Repair
Zone failures, circulator pumps, zone valves, glycol — all hydronic systems.
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Ignition Failure Repair
Boiler won't fire? Lockout codes? Full ignition system diagnosis.
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Glycol Testing & Flush
Protect your heat exchanger from corrosion — annual glycol service.
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Annual Maintenance
Full pre-season tune-up — combustion analysis, inspection, glycol test.