Tankless water heater service and installation

No. Water still must travel through the piping. A recirculation design may reduce wait time in some homes.

Only if it is sized for the combined flow and winter incoming-water temperature.

Intervals depend on the manufacturer and water quality. Scale-prone water may require more frequent service.

Some systems require very large electrical capacity. A load review is essential before choosing one.

It is the slug of cool water you feel part-way through a shower shortly after someone else has used hot water. When a tap closes, hot water is left sitting in the pipe. Reopening it delivers that hot water first, then the cooler water that was between the burner and the pipe while the unit was firing back up, then steady hot water. It is characteristic of tankless systems rather than a fault, and modern units with a small internal buffer tank or a recirculation loop largely eliminate it: worth asking about if the household has back-to-back showers.

Answer three questions honestly before the sales conversation. Does the gas supply and vent path exist or can it be added at reasonable cost? Is hot-water demand steady instead of occasional, since the payback comes from eliminating standby losses and a lightly used house has few to eliminate? And will you actually do the annual descale? A Vermont household with high, consistent demand and adequate gas service is a strong candidate. A seasonal camp is usually not, though freeze protection is a separate reason tankless suits some second homes badly and others well.

This is the least DIY-friendly water heater job there is, and the reason is capacity, not plumbing. A gas tankless unit typically needs a substantially larger gas supply line than the tank it replaces and a dedicated sealed vent, and an electric whole-house tankless can need 100 to 150 amps of dedicated service, which many Vermont houses simply do not have spare. People discover this after the unit is bought. Have the gas line, the vent and the electrical panel assessed before you commit to the equipment.

It loses output first and fails early second. Scale deposits on the heat exchanger insulate it, so the burner works harder for less hot water, efficiency drops and the unit starts short-cycling or throwing error codes. On Vermont's harder water the interval matters more than the manufacturer's generic guidance suggests, and heat-exchanger replacement is expensive enough that neglecting a descale is a genuinely costly habit rather than a minor one.

Twenty years is a realistic expectation against eight to twelve for a conventional tank, and that longer life is most of the financial argument for them. The trade is annual attention: descaling every one to two years on hard water, plus cleaning the inlet filter and checking the venting. A tankless unit that is serviced outlives two tanks. One that is never serviced often does not outlive one.

Generally yes, and usually more scrutiny than a tank swap, because the gas line sizing, the venting and sometimes the electrical all change. That is a feature, not a nuisance: the failure modes of an undersized gas line and an improper vent are combustion problems, and the inspection is the step that catches them. Confirm the permit is included in the quote and that the installer, not you, is arranging the inspection.

Tankless heat exchangers commonly carry 12 to 15 year warranties, longer than a tank's, but nearly every manufacturer conditions that on documented annual descaling: skip the maintenance and the warranty can be denied on a claim even though the unit is still within its stated term.

Skipping the annual descale because the unit is still working fine. Scale builds invisibly until output has already dropped and the warranty's maintenance requirement has already lapsed, so the mistake is usually discovered at the exact moment it becomes expensive.