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Cost to Install a Tankless Water Heater

Installing a tankless water heater involves shutting off and removing the existing tank, mounting the new unit, connecting water and gas lines, and running PVC venting through an exterior wall. It is a hard job because the location must accommodate the unit, electrical connection, gas supply, and fresh-air intake and venting.

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Common reasons homeowners do this job

  • A tank-style water heater is worn or damaged.
  • A homeowner is upgrading from a tank water heater to a tankless unit.
  • An existing water heater is being replaced as part of plumbing work.
  • A recirculation-pump setup needs a cross-over valve at the furthest plumbing fixture.

DIY or call a pro?

A licensed professional should install a tankless water heater because the work involves natural-gas piping and electrical connections. Improper installation can cause gas leaks, carbon monoxide poisoning, or fire hazards. Check with your local building department whether this work needs a permit.

Frequently asked questions

Can I install a tankless water heater myself or should I hire someone?
Hire a licensed professional. The installation combines gas piping, electrical work, copper water-line connections, exterior-wall venting, and leak testing; improper work can create gas-leak, carbon-monoxide, or fire hazards.
What makes tankless water heater installation cost more?
The price can rise with the job size and number of units, labor time, materials, removal and disposal of the old tank, and a small-job minimum or trip charge.
What should be checked before choosing a location for a tankless water heater?
Identify a suitable location on the wall for mounting the unit and confirm there is a suitable route for the fresh-air intake and vent. Also verify whether the existing gas line is sufficient or needs to be larger, and whether a new electrical outlet is needed near the unit.
Why does a tankless water heater need an exterior-wall opening?
The exterior-wall opening provides the route for the fresh-air intake and vent. PVC pipe and fittings are used for the venting, so the mounting location must allow those pipes to be run and secured.

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