Combi Boilers Install
Fast, Reliable Combi Boiler Repairs by Markham Heating & Air Conditioning
When your combi boiler stops working, you lose both heat and hot water at the same time. Our certified technicians respond quickly to diagnose and repair all major combi boiler brands and models. At Markham Heating & Air Conditioning, we fix the root cause so your home stays warm and your hot water keeps flowing through Ontario’s coldest months.
Combi Boiler Repair Services
Let Markham Heating & Air Conditioning Restore Your Heat and Hot Water Quickly and Safely
Rapid No-Heat & No-Hot-Water Response
Our technicians arrive quickly with the tools and parts needed to fix most combi boiler problems in one visit, restoring heat and hot water fast.
Pinpoint Fault Diagnosis
We diagnose error codes, low pressure, leaks, and strange noises using manufacturer-approved procedures to find and fix the real problem.
Trusted Local Repair Experts
As a reliable local company, we provide honest assessments, transparent pricing, and lasting repairs you can depend on, with no hidden fees.
Call us, or send us an email for a free estimate
Our Repair Promise
We take pride in delivering fast, honest, and stress-free combi boiler repairs from start to finish. Our technicians explain the problem clearly, give you an upfront quote before any work begins, and make sure your system runs safely and reliably before we leave.
Upfront, Honest Pricing
We explain the problem and give you a clear quote before any work begins, so there are no surprises or hidden fees on your bill.
OEM-Approved Parts
We repair and replace pumps, valves, sensors, and heat exchangers using OEM-approved parts whenever available for lasting results.
Safety & Pressure Testing
After every repair, we test system pressure, gas connections, and venting to confirm your combi boiler is running safely and reliably.
Clean Work & Clear Advice
We leave your home clean, walk you through the repair, and give honest advice on whether future repair or replacement makes more sense.
Combi Boiler Repairs
If your combi boiler isn’t providing heat or hot water, we’re here to help. We service all major brands and provide fast, accurate diagnostics.
Is Your Combi Boiler Acting Up? Run Through This Checklist First
Before calling a technician, take a few minutes to check these items — it could save you the cost of a service call.
- Is the thermostat set correctly? Confirm the thermostat is set to Heat and the temperature is above the current room temperature. Also, check that the hot water temperature setting hasn’t been accidentally lowered.
- Is there an error code on the display? Most combi boilers display a fault code when something is wrong. Take a photo of the code and have it ready when you call — it helps us diagnose faster.
- Has the circuit breaker tripped? Combi boilers run on a dedicated circuit. Check your panel and confirm the breaker is fully on.
- Is the gas supply on? Confirm the gas shutoff valve near the unit is open (handle parallel to the pipe = open). If other gas appliances in your home aren’t working either, contact Enbridge Gas at 1-866-763-5427.
- Is the condensate drain clear? High-efficiency combi boilers produce condensate. A blocked or frozen drain line can trigger a system lockout. Check that the drain line isn’t kinked or obstructed.
- Is the system pressure correct? Check the pressure gauge on the unit — most combi boilers operate between 1 and 1.5 bar when cold. Low pressure can prevent the system from firing. Do not attempt to re-pressurize unless you’re familiar with the process.
If you’ve worked through this list and your combi boiler still isn’t operating properly, give us a call. Markham Heating and Air Conditioning is ready to help — we service all major brands.
Combi Boiler Maintenance & Tune-Up
A combi boiler tune-up is preventative maintenance designed to keep your system delivering reliable heat and on-demand hot water — before small issues become expensive repairs. Regular servicing extends equipment life, helps maintain warranty requirements, and ensures your boiler operates safely and efficiently all year.
When you book a tune-up with Markham Heating and Air Conditioning, a fully licensed technician will perform a thorough inspection of your combi boiler. We service all major combi boiler brands.
Here are a few items covered in our inspection:
| Inspection Item | Why It Matters |
|---|---|
| Thermostat & controls check | Confirms the system responds correctly to heating and hot water calls |
| Gas pressure check & adjustment | Proper gas pressure is critical for safe and efficient combustion |
| Condensate drain inspection | A blocked drain can cause a system lockout — checked and cleared as needed |
| Heat exchanger inspection | Checks for scale buildup or damage that reduces efficiency and heating output |
| Burner & ignition check | Ensures reliable ignition and clean combustion on every firing |
| Flue & venting inspection | Confirms exhaust gases are safely venting outside the home |
| System pressure check | Verifies operating pressure is within the manufacturer's specified range |
A full written report of our findings is available on request after every tune-up, so you always know exactly where your combi boiler stands.
Why it matters
Regular tune-ups help catch worn parts before they fail, keep your system running efficiently, and protect against safety risks. Staying current with annual maintenance can also be a requirement for keeping your equipment warranty valid.
Ready to book your combi boiler tune-up?
Our Brands
Navien
High-Performance Combi Boilers — NCB-H and NFC-H Series