What Changes the Cost of a Tankless Installation

Two quotes for "a tankless water heater" can be far apart and both be honest, because the heater is only part of the job. We don't publish a flat price, because the work around the heater is what varies most from house to house. Here is what drives it.

Fuel

A gas or propane heater is simplest where that fuel is already piped to the location. Switching from an electric tank to gas means running fuel to a new spot. Whole-house electric tankless heaters need very large electrical capacity, which many homes don't have.

Gas supply

At full output, a gas tankless heater can draw far more gas than the tank heater it replaces. The gas line has to be sized for that load along its whole length, and sometimes the meter or a propane regulator needs attention too. Checking this is part of an estimate, not an afterthought. ^[1]

Venting

Gas tankless heaters need their own vent system to the outdoors, using the materials and routing the manufacturer specifies. Condensing models cannot vent through a chimney or share venting with other appliances, so the old tank's vent usually can't be reused. ^[2] A short, direct run through an outside wall is a smaller job than a long run or a roof penetration.

Condensate

High-efficiency condensing tankless heaters produce acidic condensate. It needs a proper drain, local codes may require a neutralizer, and in a cold basement or on an outside wall that drain has to be protected from freezing. ^[2]

Electrical

Gas tankless heaters need electricity for controls, fans and ignition, usually from a nearby outlet or circuit. Recirculation pumps and some accessories add to that.

Location and piping

Keeping the heater where the old one was is usually simplest. Moving it, mounting it outdoors, or reworking hot water piping and adding recirculation adds work. Outdoor and freeze-exposed locations also need freeze-protection planning.

Removal of the old heater

Draining, disconnecting and disposing of the existing tank is part of the job, and harder in tight or awkward spaces.

Permits and inspection

New Hampshire state law treats installing a gas or propane water heater as licensed gas-fitting work, and towns issue the permits. ^[3] In Laconia, gas permits need a piping diagram and a pressure test form. ^[4] The permit and inspection are part of the real cost of doing the job properly.

Getting comparable quotes

Ask each installer to list the model and its output at your winter temperature rise, what gas-line, venting, condensate and electrical work is included, who pulls the permit, and what is excluded. Quotes that spell these out can be compared; a single number cannot.

For an estimate on your home, request one here or call us.