Tankless Water Heater Repair in Calgary
Running out of hot water? We diagnose and fix your tankless or on-demand water heater the same day — with upfront pricing and no surprises.
Common Tankless Water Heater Problems We Fix in Calgary
1. Scale & Mineral Buildup — Calgary's #1 Tankless Problem
Hard water deposits build up inside your heat exchanger over time, reducing efficiency and eventually causing your unit to shut down. Annual descaling keeps it running like new.
2. Ignition Failure
Your unit fires up, but no hot water comes out. Ignition failures are often caused by a dirty or faulty igniter, gas supply issues, or a tripped safety sensor — all diagnosable in one visit.
3. Cold Water Sandwich Effect
You get a brief blast of hot water, then cold, then hot again. This known tankless quirk gets worse as internal components wear out — and it’s fully fixable.
4. Venting & Exhaust Blockage
Blocked or improperly installed venting shuts your unit down as a safety measure. Common in Calgary homes after winter debris accumulates in outdoor vent caps.
5. Flow Sensor Failure
Your heater needs to detect water flow before it fires. A worn or dirty flow sensor means your unit doesn’t know when to turn on — leaving you with cold water every time.
6. Electric Element Burnout
For electric tankless units, heating elements wear out over time. We stock common replacement elements for all major brands and can usually complete repairs same-day.
What Does Tankless Water Heater Repair Cost in Calgary?
Repair costs vary depending on what’s wrong with your unit. Here’s a realistic breakdown of what Calgary homeowners typically pay — no fluff, no bait-and-switch.
| System Type | Typical Range (CAD) |
|---|---|
| Diagnostic / Service Call | $100 – $150 |
| Flow Sensor Replacement | $150 – $300 |
| Scale Flush / Descaling Service | $150 – $250 |
| Igniter / Ignition Module | $200 – $400 |
| Circuit Board / Control Module | $300 – $600 |
| Heat Exchanger Repair | $400 – $800+ |
| Full Unit Replacement (installed) | From $4,980 |
Before we touch anything, we give you a clear, written quote. No work starts until you approve it.
If the repair cost doesn't make sense relative to the age of your unit, we'll tell you honestly — even if that means recommending a replacement instead.
No pressure. No upsell. Just straight talk.
We Repair All Major Tankless Water Heater Brands in Calgary
Our technicians are factory-trained on all major brands installed in Calgary homes. We carry OEM-compatible parts for the most common makes in our service vehicles.
Rinnai
Calgary's most popular tankless brand. We repair all Rinnai series including the RL, RU, and Sensei lines, and diagnose all Rinnai error codes.
Navien
Condensing tankless and combi units. We diagnose Navien error codes and repair heat exchanger and control board issues.
Noritz
High-efficiency gas tankless units. We carry common Noritz parts and offer fast turnaround on most repairs.
Rheem
Both gas and electric tankless models. We service the full Rheem Performance and Platinum series across all Calgary homes.
Bosch
Electric and gas tankless units. We fix Bosch Tronic and Greentherm series with same-day parts availability.
IBC
Combi-boiler and tankless hybrid systems. We have extensive experience with IBC's combined heating and hot water units.
Don’t see your brand?
Call us at (403) 399-7903 — if it's a tankless or on-demand water heater, we can fix it.
Signs Your Tankless Water Heater Needs Repair
Most Calgary homeowners don’t think about their hot water heater until something goes wrong — usually mid-shower. If you’re noticing any of these warning signs, don’t wait. Call us before a small fix turns into a full replacement.
Your tap runs cold no matter how long you wait. This usually points to an ignition failure, gas supply issue, or a tripped error code — all fixable with a same-day service call.
One minute it's hot, the next it's cold. Fluctuating temps are a classic sign of a failing flow sensor or mineral buildup blocking consistent heat output — both common in Calgary.
Rinnai, Navien, Noritz, and Rheem all use error codes to flag specific faults. If your unit is flashing a code, that's your heater telling you exactly what's wrong — and we know how to read every one of them.
Banging, rumbling, or hissing coming from your on-demand water heater usually means scale buildup from Calgary's hard water, or a pressure relief valve issue.
Even a small drip around your tankless unit shouldn't be ignored. Leaks can damage walls, floors, and the unit itself. We locate and fix the source fast — most leaks are fixed same-day.
If your gas or electricity bill is climbing but your usage hasn't changed, your tankless heater may be working overtime to compensate for a failing component — costing you money every day.
Should You Repair or Replace Your Tankless Water Heater?
Tankless water heaters last 15–20 years with proper maintenance. But if yours is older or the repair cost is high, replacement might be the smarter move. Here’s a quick way to think it through.
Repair If…
- Your unit is under 10 years old
- The repair cost is less than 50% of a new unit installed
- The problem is a single component — sensor, igniter, or element
- This is the first time you've needed a repair
Consider Replacing If…
- Your unit is over 12–15 years old
- You've had multiple repairs in the last two years
- The heat exchanger is cracked or corroded
- Repair cost exceeds 50% of a new unit installed
Our technicians give you an honest, no-pressure assessment on-site. If replacement makes more sense, we'll walk you through your options. See our tankless water heater installation page →
How Our Hot Water Tank Installation Works
Fast. Transparent. Done right the first time. Here’s what to expect when you call Comfort Union.
You Call, We Show Up
Call (403) 399-7903 and we'll schedule you same-day or next-day. We serve all Calgary neighbourhoods — NW, NE, SW, and SE — with no extra travel fees.
Fast, Accurate Diagnosis
Our technician arrives with a fully stocked van. We run a complete diagnostic, identify the exact fault — error code, failed component, or Calgary hard water issue — and explain it in plain language.
Upfront Quote Before Any Work
You get a written quote before we start. No surprises on the invoice. If we find anything additional during the repair, we tell you first — always.
Repair Done, Follow-Up Included
Most repairs are completed in a single visit. Once done, we test the unit fully, walk you through what was fixed, and share simple tips to extend the life of your heater.
Before & After — Tankless Water Heater Repairs in Calgary
Real jobs. Real results. See the difference a proper repair makes.
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Why Calgary Homeowners Choose Comfort Union for Tankless Repair
There’s no shortage of plumbers in Calgary. Here’s why thousands of homeowners call us first — and keep calling us back.
We've been in Calgary homes since 1995. We know how hard water here affects tankless units — and we fix it every day across every neighbourhood.
Every technician holds a Red Seal HVAC/R certification and Gas Fitting ticket. No apprentices working unsupervised on your home.
We carry parts for Rinnai, Navien, Noritz, Rheem, and IBC on every van. Most repairs are completed in a single visit — no waiting around for parts.
If a repair isn't worth it, we'll tell you. We'd rather earn your trust with an honest answer than push a repair that won't last.
What Calgary Homeowners Are Saying
Great experience with Comfort Union! My tankless system was making strange noises and not performing well. They diagnosed the problem quickly and got it running like new again. Very knowledgeable team and excellent customer service.
Comfort Union saved me from a cold shower nightmare. Booking was easy, they arrived on time, and the repair was done efficiently. I really appreciated how they took the time to explain maintenance tips to prevent future issues. Will definitely use them again!
I had an issue with my tankless water heater suddenly losing hot water, and Comfort Union came through fast. The technician was professional, explained everything clearly, and had it fixed the same day. Pricing was fair and transparent. Highly recommend their service!
Tankless Water Heater Repair FAQ — Calgary
Everything Calgary homeowners ask before booking a repair. Don’t see your question? Call us at (403) 399-7903 — we’re happy to help.
How much does it cost to repair a tankless water heater in Calgary?
Most repairs range from $150 to $600 depending on the issue. A diagnostic service call typically runs $100–$150, which is applied toward your repair if you proceed. We give you a written quote before starting any work — no surprises.
How do I know if my tankless water heater needs repair or replacement?
If your unit is under 10 years old and the repair is under 50% of replacement cost, repair usually makes sense. Over 12–15 years with recurring issues, replacement is often the smarter call. We’ll give you an honest, no-pressure recommendation on-site.
Do you offer emergency tankless water heater repair in Calgary?
Yes. We offer 24/7 emergency service across all Calgary neighbourhoods. Call (403) 399-7903 any time — we’ll get a technician to you as fast as possible. No one should go without hot water longer than they have to.
What brand of tankless water heater do you repair?
We service all major brands including Rinnai, Navien, Noritz, Rheem, Bosch, and IBC. If it’s a tankless or on-demand water heater, we can fix it. Call us if you’re unsure about your specific brand or model.
What does it mean when my tankless water heater shows an error code?
Error codes are your unit’s way of flagging a specific fault — like a flow sensor issue, ignition failure, or overheating. Rinnai, Navien, and Noritz each use their own code systems. Our technicians are trained on all of them and arrive equipped to diagnose and fix in one visit.
What does my hot water keep going cold then hot again?
This is called the cold water sandwich effect — a known quirk of tankless systems that gets worse as components wear out. It can also be caused by a failing flow sensor or a dirty heat exchanger. Both are repairable and we fix them regularly across Calgary.
Does Calgary’s hard water damage tankless water heater?
Yes — and faster than most homeowners realize. Calgary has naturally hard water, which causes mineral scale to build up inside your heat exchanger over time. This reduces efficiency and can permanently damage your unit if left too long. Annual descaling is the best prevention — we offer it as a standalone service.
How long does a tankless water heater repair usually take?
Most repairs are completed in a single visit — usually 1 to 2 hours. Our vans are stocked with common parts for all major brands, so we rarely need to make a second trip. Complex heat exchanger work may take longer.
Can a tankless water heater be repaired, or do, I need to replace it?
In most cases, yes — a tankless water heater can be repaired. The main exception is a cracked or corroded heat exchanger, which is usually not cost-effective to fix. We’ll tell you honestly which situation you’re in — no guesswork, no pressure.
How often should a tankless water heater be serviced in Calgary?
Once a year is ideal — especially in Calgary where hard water accelerates scale buildup. Annual maintenance includes a flush and descale, filter cleaning, and a full system inspection. It extends the life of your unit and keeps your manufacturer warranty valid.
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