Tankless water heater installation
A tankless installation is four jobs in one: sizing, gas, venting and water. Here is what each involves, so you know what you are paying for and why a cheap install is rarely a good one.
The four parts of a tankless install
What gets done
- SizingBathrooms, simultaneous fixtures and Seattle’s winter inlet temperature set the flow rate. Undersizing is the most common tankless complaint, and it is a design error, not a product fault.
- GasThe burner needs more gas than a tank. We check the meter capacity and usually upsize the line to the unit.
- Venting and condensateCondensing units vent in PVC or polypropylene to the outside and produce acidic condensate that must drain safely, often through a neutraliser and a condensate pump.
- Water and service valvesNew supplies, a pressure check, and isolation valves with service ports so the unit can be flushed every year without disconnecting anything.
- Permit and inspectionPulled by us, inspected by the city, paperwork to you.
On the day
Most installations take one day. We drain and remove the old heater, mount the new unit on a backer board, run the gas and vent, connect the water, fire it up and set the temperature, then test every fixture in the house for flow and temperature.
If the gas meter needs upgrading, that is coordinated with Puget Sound Energy ahead of time so the install day is not held up.
Where it goes wrong, and how we avoid it
Undersized gas lines cause error codes under load. Venting with the wrong pitch collects condensate. Missing isolation valves make the annual flush a two-hour job. We have fixed all three on units other people installed, and we build ours so nobody has to.
Licensed, local, and on the record
- Licensed Bonded and insured in Washington
- Founder 15+ yrs in the plumbing trade
- Always Free estimates
- Available Same-day service
- Our promise 100% satisfaction guaranteed
Installation questions
Where can a tankless unit go?
On an exterior wall or near one for short venting, close to the gas supply, with a drain for condensate. Garages, utility rooms and mechanical closets are typical. Outdoor-rated units exist for mild climates like Seattle’s.
Can it go where the old tank was?
Usually, if there is a wall to mount it and a route for the vent. We confirm during the estimate.
Electric tankless or gas?
For a whole house in Seattle, gas. Whole-house electric tankless units need very large electrical service that most homes do not have. Electric point-of-use units make sense for a single remote sink.
Talk to a Seattle plumber today
Tell us what is happening and we will give you a free, written estimate. Same-day service is available for most calls. No pressure, no obligation.
Serving Seattle, Shoreline, Bellevue and Mercer Island.