Most tankless water heater breakdowns are not random — they're the predictable result of neglected maintenance. Here's the progression that plays out in unserviced units across Ontario every year:

Year 1–2: Scale Begins Accumulating

Ontario's water supply — particularly across the GTA, Hamilton, and surrounding areas — contains dissolved minerals, primarily calcium and magnesium. Every litre of water that passes through your tankless heater deposits a microscopic layer of these minerals inside the heat exchanger. It's invisible at first, and the unit runs normally. But the accumulation is constant.

Year 2–4: Efficiency Begins to Drop

As scale builds on the heat exchanger's internal surfaces, it acts as an insulating barrier between the burner's heat and the water passing through. The unit must work harder — burning more gas and running longer cycles — to deliver the same output temperature. You may notice slightly higher gas bills or a subtle drop in hot water temperature under peak demand. The unit is still working, but it's working harder than it should.

Year 3–6: Audible Warning Signs Appear

Significant scale buildup causes the heat exchanger to overheat locally, creating the rumbling, kettling, or popping sounds that homeowners often notice and dismiss as normal. These sounds are not normal — they are your unit telling you it's under stress. Error codes begin appearing with increasing frequency. Hot water temperature becomes inconsistent. Efficiency losses of 15–25% are common at this stage.

Year 5–8: Component Failures Begin

Chronic overheating from scale insulation damages thermistors, triggers thermal fuse failures, and stresses the heat exchanger itself. Repair calls become more frequent. Each repair addresses a symptom without fixing the underlying cause — scale. If the heat exchanger develops a crack from repeated thermal stress cycles, the unit typically cannot be repaired economically and must be replaced years before the end of its designed lifespan.

The Warranty Problem

Most major tankless water heater manufacturers — including Rinnai and Navien — require documented annual maintenance as a condition of their heat exchanger warranty. A heat exchanger failure on a unit that has no maintenance records is frequently denied under warranty, leaving the homeowner responsible for the full replacement cost. One annual maintenance visit per year is typically all that's required to keep your warranty intact.

Each maintenance visit is performed by a licensed HVAC technician and covers every critical system in your tankless water heater. Here's exactly what happens during your annual service:

The most common objection to a maintenance plan is: "My unit seems fine — why pay for service I don't need?" Here's what the numbers actually look like when you skip maintenance vs. when you maintain consistently:

A single emergency repair call — for something a maintenance visit would have caught — typically costs more than an entire year's maintenance plan fee. And that doesn't account for the efficiency losses you've been paying for on every gas bill in between.

Water hardness — the concentration of dissolved calcium and magnesium — varies significantly across Ontario, and it has a direct impact on how quickly scale builds in your tankless heater. The harder your water, the faster scale accumulates, and the more critical annual descaling becomes.

gpg = grains per gallon. Values are approximate. Your technician can advise on your specific local water quality during your first maintenance visit.

If your region has hard water, we may also recommend pairing your tankless heater with a whole-home water softener to further extend unit life and reduce descaling frequency. Ask us about our water filtration and softener options when you call.

We offer two maintenance plan tiers so you can choose the level of coverage that suits your household and budget. Both plans include our full annual service visit — the difference is in how much additional repair coverage and peace-of-mind protection you want on top of that.

Not sure which plan is right for you? Our team will recommend the best fit based on your unit's age, your local water hardness, and your household's hot water usage. Call 1-888-675-5907 for a free recommendation.

Here's exactly how a Constant Home Comfort maintenance visit works from start to finish:

1. Scheduling: We contact you ahead of your annual service date to confirm a time that works. Plan members are never left to remember on their own — we track your schedule and reach out proactively.
2. Arrival: A licensed HVAC technician arrives at your home in a marked Constant Home Comfort vehicle, in uniform, at your scheduled time. Identification is carried and available on request.
3. Pre-service walkthrough: The technician does a brief walk-through with you to note any concerns you've observed — unusual sounds, temperature inconsistency, error codes you've seen — and inspects the unit visually before beginning service.
4. Descaling flush: The technician isolates the unit's water connections and circulates our descaling solution through the heat exchanger using a dedicated flush kit. This typically takes 45–60 minutes and requires no work from you.
5. Full inspection checklist: While the flush runs, the technician completes the full inspection checklist: venting, gas pressure, burner, sensors, flow sensor, error code scan, condensate drain (if applicable), and water connections.
6. Findings review: At the end of the visit, the technician walks you through any findings, addresses questions, and provides a written service report detailing everything completed and any recommendations for follow-up.
7. Documentation: Your service record is updated and a copy is provided to you for your warranty files. For plan members, we retain this on file as well.

Total time on site is typically 1.5 to 2.5 hours depending on the unit's condition and any additional findings. No water is needed from you during the service — we bring everything required.

Our maintenance plan is the right choice for any Ontario homeowner who owns a tankless water heater. It's especially valuable if any of the following apply to you:

• You installed your tankless heater with Constant Home Comfort and want to protect your investment for the long term
• Your unit is 2 years old or more and has never been professionally serviced
• You live in a moderate to hard water area — GTA, Hamilton, Waterloo, Kitchener, London, or surrounding regions
• You rely heavily on hot water — large household, frequent simultaneous use, teenagers with long showers
• Your unit is still within the manufacturer's warranty period and you want to preserve coverage
• You want priority service access and peace of mind without the commitment of a full protection contract
• You've experienced a repair in the past and want to prevent the next one before it happens

How often does a tankless water heater need to be serviced?

Once per year for most Ontario homes. In areas with very hard water — particularly Waterloo, Kitchener, Hamilton, and parts of the GTA — we may recommend a mid-year filter check in addition to the full annual service. Your technician will advise you based on your specific water quality and usage patterns during the first visit.

My unit is brand new — do I really need a maintenance plan yet?

Yes — and here's why. Scale starts accumulating from the very first litre of water that passes through the unit. Starting your maintenance plan from year one means scale never gets a foothold, your warranty is protected from the beginning, and your technician establishes a baseline reading of your unit's performance that makes future issues easier to spot. Units that start maintenance-plan servicing from new consistently outperform and outlast those that begin servicing only after problems appear.

Can I join the maintenance plan if I didn't install my unit with Constant Home Comfort?

Yes. Our maintenance plan is open to any Ontario homeowner with a tankless water heater, regardless of where or when it was installed. We service all major brands including Rinnai, Navien, Rheem, Bradford White, A.O. Smith, GSW, Giant, and John Wood. We'll conduct an initial inspection visit to assess the unit's current condition before enrolment.

What if something needs to be repaired during the maintenance visit?

If the technician identifies a component that needs replacement during the maintenance visit, they'll explain what's needed, the associated cost, and whether it's urgent or can wait. No repair work is done without your explicit approval. Plan members receive a labour discount on any repair work identified during or following a maintenance visit — see plan tiers above for details.

Does the maintenance plan cover parts?

The Essential Plan covers the full service labour for all maintenance tasks listed above, with small parts (such as inlet filters and PRV replacements) billed at cost if needed. The Complete Plan includes inlet filter and PRV replacement parts within the plan fee. Neither plan is a comprehensive parts warranty for major component failures — for that level of coverage, contact us to discuss extended protection options.

Is there a contract or minimum commitment?

Our maintenance plan is renewed annually. There is no multi-year lock-in — you renew each year at the current plan rate. We'll notify you before your renewal date so you're never auto-charged without notice.

What is the descaling solution you use — is it safe?

We use a food-grade citric or phosphoric acid solution specifically formulated for tankless water heater descaling. It is non-toxic, biodegradable, and safe for all plumbing materials. After the flush cycle, the heat exchanger is rinsed with fresh water before the unit is returned to service. There is no lingering taste, odour, or residue in your hot water.

Protecting a 20-year investment costs less than one emergency repair call. Constant Home Comfort's Tankless Maintenance Plan gives you annual professional servicing, priority emergency access, warranty protection, and the peace of mind that comes from knowing your hot water supply is in expert hands — across all of Ontario, every day of the year.

Call 1-888-675-5907 to enrol or ask about current plan pricing. Serving Toronto, the GTA, Hamilton, Ottawa, London, Waterloo, Barrie, and all of Ontario.