Tankless water heaters: the honest pros and cons

Straight up: we are a drain, sewer and pumping company. We do not sell or install water heaters, so this is information rather than a pitch, and for an installation quote you want a general plumbing contractor. We keep this here because the hard-water angle is genuinely local and genuinely under-mentioned.

The case for tankless

• Endless hot water — it heats on demand rather than holding a finite tank
• Lower standby losses, since nothing is being kept hot for hours you are not using it
• Considerably smaller, which frees up real floor space
• Longer service life than a tank unit, often meaningfully so, with maintenance
• No tank means no tank to fail and empty itself across a floor

The case against

• Higher purchase and installation cost, sometimes substantially — gas units often need a larger gas line and a different flue
• Flow-rate limits: running two showers and a dishwasher simultaneously can outrun a unit that is undersized
• A short delay before hot water arrives, and a possible cold slug if the flow drops below the activation threshold
• Electric models can demand serious electrical capacity, occasionally a service upgrade

The hard-water problem nobody mentions

This is the one that matters in San Juan County. A tankless unit passes water through a narrow heat exchanger, and hard water deposits scale inside it. Scale reduces efficiency, then triggers error codes, then shortens the life of the unit.

They need descaling — typically annually here, which is more often than the manual will suggest for a national average. That is either a service visit every year or a job you take on yourself with a pump and a bucket of descaling solution.

Who they actually suit

Good fit: smaller households, homes short on space, anyone who genuinely runs out of hot water with a tank, and people who will keep up with the maintenance. Less good: large households with heavy simultaneous demand, anyone on a tight installation budget, and anyone who will never descale it.