Get fast, reliable tankless (on-demand) water heater repair from certified pros—condensing and non-condensing, any brand. This guide explains when to call, what we fix, how our diagnostics work, and how to prevent future issues. We serve homes and businesses across the Greater Toronto Area (GTA).
Quick Highlights
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24/7 emergency tankless repair & same-day service
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Licensed, insured technicians for gas & electric tankless systems
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Upfront, no-surprise pricing before any work begins
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OEM-grade parts and code-compliant workmanship
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Post-repair performance testing (GPM @ ΔT, combustion/electrical, condensate & venting)
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Optional Tankless Water Heater Protection Plan to prevent repeat issues
Signs You Need Tankless Service
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No hot water, temperature swings, or “cold-water sandwich”
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Unit shuts off mid-shower or displays error codes
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Low flow at taps/showers despite good cold-water pressure
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Scale buildup symptoms: loud burner/fan, oscillating temps, frequent lockouts
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Water leaks at isolation valves, condensate lines, or vent joints
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Exhaust/vent smell, backdraft alarms, or visible corrosion on venting
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Unusual noises: whistling, chattering, rattling, or fan roar
Safety note: If you smell gas, shut off the gas supply, ventilate the area, and call your utility and us. If you notice electrical burning smells, turn the unit off at the breaker.
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Hydronic & Combustion: gas valves/regulators, ignition electrodes, flame sensors, burner assemblies, fans/blowers
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Controls & Sensors: PCBs, thermistors, flow sensors/turbines, pressure switches, dip switches/firmware resets
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Heat Exchanger & Scale: chemical descaling/flush, isolation valve service, screen/strainer cleaning
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Expansion & Mixing: mixing/tempering valves, recirculation pumps/controls, bypass valves
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Venting & Condensate: direct/concentric vent leaks, termination issues, traps, neutralizers, condensate pumps
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Gas/Electrical: line sizing & pressure verification, dedicated circuit checks (electric tankless), grounding/fusing
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Water Quality Issues: odour/discolouration diagnostics (anode interaction upstream, stagnation), hardness mitigation advice
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Diagnosis & Safety Check
Retrieve error history, test gas pressure & combustion, verify electrical supply, inspect venting/clearances, measure inlet temperature and ΔT. -
Clear Options & Pricing
You’ll receive a written estimate with good/better/best repair paths (when applicable) and parts availability. -
Expert Repair
We install OEM-grade parts (or approved equivalents), correct code issues, and clean work areas. -
Commissioning & Verification
We confirm GPM at your target ΔT (to ~120°F/49°C), stabilize outlet temperature, verify recirculation (if present), and validate condensate/neutralizer operation. -
Prevention Tips & Warranty
We explain root cause (e.g., scale, undersized gas, venting), outline maintenance, and record/register applicable warranties.
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Flat, upfront quotes before any work—no hidden fees
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If repair costs approach replacement value, we’ll provide a repair vs. replace comparison (efficiency, comfort, available incentives) so you can choose confidently
Considering an upgrade? Explore Get a Tankless Water Heater for sizing, recirculation options, financing, and rebates.
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Annual descaling/flush (more often in hard water)
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Clean inlet screens/flow sensors and check recirculation settings
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Inspect condensate traps/neutralizer media (condensing models)
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Verify vent termination & clearances; keep intake/exhaust clear of debris/snow
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Maintain setpoint around 120°F / 49°C unless higher temps are needed with a mixing valve
Add our Tankless Water Heater Protection Plan for annual descaling, priority service, repair discounts, and safety/venting checks—including flow-sensor cleaning and combustion analysis. Preventive maintenance extends unit life, maintains peak efficiency, and keeps your hot water endless and reliable.
Proudly serving the Greater Toronto Area (GTA) and surrounding communities. Contact us to confirm availability in your neighborhood.
- Get a Tankless Water Heater
- Tankless Water Heater Repair
- Tankless Water Heater Rebates & Incentives
- Tankless Water Heater Buyer’s Guide
Why does my tankless shut off mid-shower?
Likely scale buildup, a dirty inlet screen/flow sensor, undersized gas line, or a failing sensor/PCB. We descale, clean screens, and verify gas/controls.
I’m getting hot–cold–hot swings. What causes that?
Common causes include scale, improper minimum flow, incorrect recirculation setup, or sensor drift. We stabilize flow/temperature and recalibrate.
There’s water under the unit—do I need a new heater?
Not always. It could be condensate, fittings, or heat-exchanger seals. We locate the source and advise on repair vs. replacement.
Do you service condensing units?
Yes—venting, condensate traps/neutralizers, and heat exchangers are all part of our diagnostics and repairs.
How long does a repair take?
Many are same-day. Special-order parts or concealed vent/gas issues may require a follow-up.
Will repairs affect my warranty?
We follow manufacturer procedures and use OEM-grade parts to help preserve eligible warranties.
Keep it running like new
Add our Tankless Water Heater Protection Plan for annual descaling/flush, priority service, repair discounts, and safety/venting checks—including flow-sensor cleaning and combustion analysis. Preventive maintenance extends unit life, maintains peak efficiency, and keeps your hot water endless and reliable.
Ready for quieter, more efficient heat? Book your free in-home quote today.
- Phone: (905) 895-7787
- Email Us: Send Email
- Service Area: Greater Toronto Area
At Coffee Heating and Air Conditioning, we proudly offer a full spectrum of residential and commercial HVAC services across Toronto and the Greater Toronto Area. From expert installation of high-efficiency furnaces, air conditioners, boilers, and water heaters to precision repairs, emergency service calls, and routine system maintenance, our certified technicians ensure year-round comfort and safety for every client. We also specialize in air quality improvements, duct cleaning, smart thermostat integration, and energy-saving upgrades tailored to your home or business. Whether you’re building new, upgrading, or need fast repairs, our team delivers responsive, reliable solutions backed by industry expertise and a commitment to excellence.
