Equipment
- KD Navien tankless gas water heater
- Repurposed gas line with new shutoff valve
- New venting per Navien spec
- New condensate drain line
- Pressure relief + shutoff valves
- Initial flush and startup test
The starting situation
A Walnut Creek homeowner wanted out of the tank-water-heater lifestyle. The existing 50-gallon tank was slow to recover after a long shower, took up significant floor space, and was old enough that replacement was on the horizon either way. They specifically wanted the Navien KD platform, on-demand hot water with high efficiency and a compact wall-mount form factor that would give them their utility room floor back.
What we installed
- KD Navien tankless gas water heater: wall-mounted, condensing high-efficiency
- Repurposed gas line with new shutoff valve: the existing gas line had adequate capacity but needed a new quarter-turn shutoff valve and a minor reroute to meet Navien’s required configuration
- New venting per Navien spec: tankless condensing units have specific venting requirements (concentric vent, slope-to-drain, length limits) that are different from a tank heater’s natural draft
- New condensate drain line: condensing-efficiency units produce acidic condensate that needs proper drainage
- New pressure relief valve and shutoff valves on the water side
- Initial system flush and startup test including temperature calibration
The detail that mattered
The selling point of a tankless is “unlimited hot water”, but only if the gas line, venting, and condensate drain are sized correctly. We see DIY-leaning installs all the time where someone bolted a tankless on the wall using the old tank’s gas line, the old tank’s vent, and just let condensate drip somewhere. The unit works for a year, then the gas demand starts starving on long draws (modulating burner can’t get enough fuel), then the venting fails inspection at the next sale of the house, then the condensate corrodes whatever it’s been dripping on for two years. The install is the difference between a 20-year appliance and an 18-month problem.
What the homeowner got
Compact wall-mount unit with the utility-room floor back. On-demand hot water: no more “wait for the next shower” recovery time. Higher efficiency than the old tank, with Navien’s factory warranty on the unit plus our 2-year labor warranty on the install.
The photos below show the installation in progress and the finished tankless unit.
Before
After
