Tankless water heater maintenance checklist
Keeping a tankless water heater in top shape comes down to a handful of regular tasks. A clear checklist helps you know what needs doing and what to leave to a licensed technician.
For Metro Vancouver and Fraser Valley homeowners, most maintenance happens during an annual service visit, with a few simple checks you can do in between.
Below, HeatLand lays out a practical maintenance checklist, explains each item, and flags the tasks that require professional, TSBC-certified expertise.
Core maintenance tasks
The heart of tankless maintenance is descaling the heat exchanger. Over time, mineral scale coats the exchanger and disrupts heat transfer, causing temperature swings and reduced efficiency. Descaling involves circulating a cleaning solution through the unit, typically once a year, to dissolve buildup and restore performance. The second core task is cleaning the inlet water filter, which traps debris before it reaches the heat exchanger; a clogged filter restricts flow and can cause temperature problems. This is a task some owners handle themselves between professional visits. Together, descaling and filter cleaning address the most common causes of declining performance. In relatively soft Metro Vancouver water, annual descaling is usually sufficient, but harder water or heavy use may call for more frequent attention. Keeping these two tasks on schedule prevents most performance issues and protects the unit’s lifespan, making them the foundation of any maintenance routine.
Inspection and safety checks
Beyond cleaning, a full maintenance visit includes several inspection and safety checks that are best left to a licensed technician. The burner and ignition system are inspected and cleaned for clean, efficient combustion. Venting is checked for blockages, corrosion, or leaks, which is critical for safely exhausting combustion gases. Gas and water connections are verified for tightness and integrity. Sensors and safety controls are tested for correct operation, and stored error codes are reviewed for early warning of developing faults. On a gas unit, the technician confirms proper combustion, looking for a clean blue flame rather than a yellow one, and checks for any signs of soot or scorching. These checks catch problems that are not obvious to an owner and are essential for safe operation. They are also the reason professional service matters: combustion, venting, and gas work fall squarely in licensed, certified territory.
What you can do versus when to call a pro
As an owner, you can safely handle a few things between visits. Keep the area around the unit clear for proper airflow and ventilation. Clean the inlet water filter periodically per your manual. Watch for warning signs, reduced flow, temperature swings, new noises, discoloured water, or recurring error codes, and note them for your technician. Keep your service records current. However, descaling a gas unit, combustion checks, venting inspection, and any gas or internal work should be done by a licensed, TSBC-certified technician. Safety note: if you smell gas, notice soot or a yellow flame, suspect carbon monoxide, or find water leaking from the unit body, do not attempt repairs; shut the unit down safely and call a professional immediately. A maintenance plan takes the guesswork out of scheduling. HeatLand offers licensed service and plans so your checklist is completed correctly and on time, every year.
Quick Checklist
- Descale the heat exchanger annually
- Clean the inlet water filter regularly
- Inspect and clean the burner and ignition
- Check venting for blockages or corrosion
- Verify gas and water connections
- Review error codes and confirm safe combustion
| Task | Frequency | Who |
|---|---|---|
| Descale heat exchanger | Annually | Licensed technician |
| Clean inlet filter | As needed / annually | Owner or technician |
| Inspect burner and ignition | Annually | Licensed technician |
| Check venting and combustion | Annually | Licensed technician |
| Keep area clear for airflow | Ongoing | Owner |
Frequently Asked Questions
What is the most important tankless maintenance task?
Descaling the heat exchanger is the single most important task. Scale buildup disrupts heat transfer and causes temperature swings and reduced efficiency, so annual descaling keeps the unit performing and extends its life. Cleaning the inlet filter is a close second. Together they address the most common performance problems.
Can I clean the tankless filter myself?
Yes, cleaning the inlet water filter is a task many owners handle between professional visits, following the manufacturer’s instructions. It is straightforward and helps maintain flow. However, descaling on a gas unit and any combustion, venting, or gas work should be left to a licensed, TSBC-certified technician for safety.
How do I know if my unit needs maintenance before its yearly service?
Watch for reduced hot-water flow, temperature swings, longer waits, new noises, discoloured water, or recurring error codes. Any of these suggests scale buildup or a clogged filter and warrants earlier attention. Note the symptoms and book service. Harder water or heavy use also means checking performance more often than yearly.
Does a maintenance plan cover the full checklist?
A professional maintenance plan is designed to complete the full checklist, descaling, filter cleaning, burner and ignition inspection, venting and combustion checks, and safety testing, on schedule each year. It removes the guesswork and ensures nothing is missed. HeatLand offers plans with licensed technicians so your unit stays properly maintained.
Reviewed by the HeatLand Heating & Cooling team — licensed HVAC contractor serving Metro Vancouver & the Fraser Valley since 1999. This article is for general guidance only. If you smell gas, suspect a carbon monoxide leak, or are unsure about any electrical or gas component, stop troubleshooting immediately and call a licensed technician or 911.