Different components have different intervals: softener salt needs topping up regularly, sediment cartridges and RO pre-filters are changed on a schedule, RO membranes and filter media last considerably longer, and valve components wear over years. Exact intervals depend on your water conditions and household usage — which is why a system fighting conditions it wasn't designed for needs attention far sooner than one that was specified correctly.

Why nobody can give you one number

You'll see maintenance intervals quoted confidently online. They're averages, and averages are built from water that isn't yours.

Three things move the number more than anything else:

  • What's in your water. A carbon filter on lightly chlorinated municipal supply and the same filter on a heavily loaded well are not on the same schedule.
  • How much water you use. Two people and six people wear a system at different rates. It's throughput, not calendar time, that exhausts media.
  • Whether the system was sized correctly. This is the one people don't expect. Equipment doing a job it wasn't specified for wears out dramatically faster.

We give you the intervals for your system at installation, based on your readings and your household. That's more useful than a number from an article.

Water softeners

Salt

Topped up periodically — how often depends on your hardness level and your usage. Keep the level above the water line in the brine tank and don't let it run empty, because a softener with no salt stops softening, quietly.

Checking the brine tank

Worth a look occasionally. Two things go wrong: a salt bridge, where a crust forms and the salt above it never reaches the water, and a salt mush at the bottom. Both mean the system thinks it's regenerating when it isn't.

Settings

If your household size changes meaningfully — kids move out, someone moves in — the programming is worth revisiting. A system set for six people serving two regenerates more often than it needs to, wasting salt and water.

Resin

Resin degrades over years. It degrades faster if it's been fighting iron or chlorine it wasn't protected from — which is a direct argument for correct sequencing. Signs it's going: hardness symptoms creeping back despite normal salt use and normal regeneration.

Valve components

Seals and moving parts wear. Preventative attention costs considerably less than a failure that floods a basement or leaves a system stuck in bypass for months without anyone noticing.

Whole-house filtration

Cartridge systems

More frequent attention by design — that's the trade-off for the lower upfront cost. Interval depends entirely on the load. A sediment cartridge on a well pulling fine material needs changing far more often than one on clean municipal supply.

If you're changing cartridges much more often than expected, that's information: either the load is higher than the system was sized for, or the micron rating is too fine.

Media tanks

Longer intervals, measured in years rather than months, but not indefinite. Media exhausts. Carbon stops reducing taste and odor; oxidising media loses capacity. The failure is gradual and quiet — the water slowly goes back to how it was, and households often acclimatise without noticing.

Backwashing systems also need their cycle checked occasionally to confirm they're still cleaning themselves properly.

Reverse osmosis

Pre- and post-filters

Changed on a schedule, and this is the one not to skip. The pre-filters exist to protect the membrane from sediment and chlorine. Let them go and you're replacing the expensive component early.

The membrane

A considerably longer interval than the filters. How long depends heavily on feed-water conditions — hardness and sediment shorten it, which is why softening ahead of an RO system often pays for itself in membrane life.

Sanitisation

Performed at service, particularly whenever the system has been opened up.

The warning sign

Reduced flow at the faucet, or a change in taste. Both usually mean a filter or the membrane is due. A slow tank refill is the same message.

Specialty treatment media

Neutralising media works by dissolving into the water — which means it depletes and needs replenishing. The interval depends on how acidic the water is and how much of it you use.

Oxidising media for iron and manganese has a finite working life and loses capacity over time. The tell is staining returning gradually.

Chemical feed systems need solution refills and periodic pump maintenance — more hands-on than media, but with more control.

Warning signs between scheduled services

Any of these is worth a call rather than a wait:

  • Symptoms you'd fixed starting to return — staining, spotting, taste, odor
  • Noticeably reduced water pressure through the house
  • A softener using much more or much less salt than usual
  • Water that suddenly tastes or smells different
  • Any sound from the equipment that's new
  • Visible leaking, weeping fittings or damp around the base of a tank
  • A system that seems to be regenerating constantly — or never

The thing that extends every interval

Correct sizing and correct sequencing.

A softener protected by iron treatment lasts longer than one fighting iron. A membrane fed softened water lasts longer than one fed hard water. Carbon installed ahead of a softener protects the resin. Sediment filtration first protects everything.

Most of the premature failures we're called to look at aren't failures at all. They're systems doing a job they were never specified to do, wearing out at exactly the rate you'd expect under those circumstances.

That's the best argument we know for testing before buying.

Inherited a system with no history?

Very common, particularly on properties bought with wells. No documentation, no idea when anything was last serviced, no idea whether it was ever right for the water.

Worth an evaluation. We'll test the water, look at what's installed, and tell you whether it's performing, needs service, or was never sized for the job in the first place.