Tankless Water HeaterMaintenance2025-12-10
Tankless Descaling and Hard Water
Annual descaling protects tankless performance and prevents scale-related faults in hard water.
Scale is a tankless water heater's main enemy. Regular descaling keeps it efficient and prevents costly faults.
Why descaling matters
Minerals deposit inside the heat exchanger, restricting flow, reducing efficiency, and eventually triggering error codes. Hard-water areas see this faster.
How often
Annual descaling (a vinegar or descaler flush through the isolation valves) is recommended — more often in very hard water. A water softener reduces the need.
Key takeaways
- Descale annually — more in hard water
- Install isolation valves for easy flushing
- A softener reduces scale build-up
- Scale codes mean overdue descaling
Need help with your tankless water heater?
Licensed, gas-certified technicians serving Greater Vancouver since 1999. CombiBoiler.ca — A division of ROMA Heating Ltd..
Frequently asked questions
More Tankless Water Heater articles
Tankless No Hot Water: CausesNo hot water from a tankless unit can be ignition, gas supply, scale, or an error-code lockout.Tankless Water Heater LeakingTankless leaks usually come from fittings, the isolation valves, or internal components — not a failed tank.Tankless Water Heater Error Codes ExplainedTankless error codes point to ignition, flow, venting, or scale issues — here's how to read them.Tankless vs Tank Water HeaterTankless gives endless hot water and saves space; tanks cost less upfront and handle big simultaneous demand simply.Tankless Installation Cost in VancouverWhat a tankless water heater costs installed in Greater Vancouver, and what drives the price.The Tankless Cold Water Sandwich ExplainedA brief cold burst between hot draws is the 'cold water sandwich' — and recirculation can fix it.
More from our knowledge base
Furnace Won't Turn On? Causes and FixesFurnaceFurnace Blowing Cold Air: What to CheckFurnaceWhy Your Furnace Short-Cycles (and How to Stop It)FurnaceNo Heat? Emergency Furnace Repair GuideFurnaceFurnace Making Strange Noises: A Sound-by-Sound GuideFurnaceAnnual Furnace Maintenance ChecklistFurnaceAll ArticlesBrowse the full library