How often should you clean your tankless inlet water filter?

These tasks are more about efficiency, longevity, and comfort. Not a huge deal if you miss one, but it pays off over time.

Staying on schedule matters beyond the repair bill: a consistent maintenance record is one of the factors in a home's Roots Home Health Score, and well-kept homes typically sell faster and closer to asking price.

How to do it

A small screen on the cold inlet catches sediment before it reaches the heat exchanger. When it clogs, hot-water flow drops and the unit can throw fault codes.

1. Shut off the cold isolation valve and relieve pressure at a hot tap.
2. Unscrew the inlet filter housing (keep a towel handy for drips) and pull out the screen.
3. Rinse the screen clean of grit and reseat it.
4. Reopen the valve and check for leaks and restored flow.

Alternatives & optional extras

• Do this at the same visit as descaling; both live on the cold inlet.
• Frequent clogging points to sediment in the supply, where a whole-house sediment filter helps.

Time: 15 minutes · Typical cost: Free

If you skip it

A clogged inlet screen starves the heater of flow, cutting hot water and triggering fault codes.

Other tankless water heater maintenance

• Descale tankless water heater — once a year

Related systems to keep on schedule

• Boiler / radiators — start with: schedule boiler service, once a year, ideally in September
• Furnace / heating system — start with: replace hvac air filter, every 3 months
• Mini-split / ductless AC — start with: clean mini-split filters, once a month
• Air conditioner — start with: schedule ac tune-up, once a year, ideally in April