Est. 1992 | Licensed Master Plumber | Fully Insured
★ ★ ★ ★ ★ | Metrowest MA
Navien · Rinnai · Rheem

Tankless Water Heater
Installation in Holliston MA.

A correctly sized tankless heater gives you endless hot water, frees up basement floor space, and lasts roughly twice as long as a conventional tank. Kiley Plumbing has installed Navien tankless units across Metrowest for over a decade.

Call for a tankless quote
508 · 429 · 2888
What's included

Tankless, done the right way.

Tankless water heaters are sensitive to two things: gas supply and venting. Most failed tankless installs we're called to fix have one of those undersized. Kiley sizes the gas line for the unit's peak BTU demand, vents per the manufacturer's spec (concentric or twin-pipe PVC, depending on the model), and condenses safely with proper drain routing.

We're a Navien specialty installer because the brand is the right balance of efficiency, longevity, and serviceable parts. For homes with smaller demand we sometimes recommend Rinnai or Rheem instead — we'll tell you what fits, not what carries the highest commission.

Every install includes a permit pulled in your town, a flat written quote, and a walkthrough showing you the isolation valves, pressure-relief, and recommended annual flushing schedule. We also coordinate Mass Save rebates and document the install for federal tax credits.

Common signs tankless is right for you

Tankless brands we install

Our process

How a tankless install goes at Kiley.

Step 01

Demand sizing

We measure your peak simultaneous fixture demand and design for cold-month groundwater temperature.

Step 02

Gas & vent design

We confirm gas supply BTU capacity and design a vent path that meets manufacturer spec.

Step 03

Install & permit

We pull a town permit, install the unit, vent to code, and wire the controls.

Step 04

Walkthrough & service plan

You get a tour of isolation valves, plus a recommended annual flush schedule (we offer to handle it).

Where we install tankless

Tankless across Metrowest MA.

Related services

FAQ

Tankless water heater FAQ.

Is a tankless water heater right for my Holliston home?
It depends on your hot water demand and your gas supply. Most Metrowest single-family homes are good candidates, but homes with very small gas service or no good vent path may need an upgrade before tankless makes sense. We assess on-site and tell you honestly.
How much does tankless installation cost?
Total installed cost in Massachusetts typically runs higher than a tank install — driven by venting, gas line sizing, and unit cost. Mass Save rebates and federal tax credits can offset a portion. We provide a flat written quote with everything included.
How long does a tankless unit last?
Properly maintained, a tankless water heater lasts 18–22 years — roughly twice a tank. Annual flushing keeps mineral buildup off the heat exchanger and is included in our service plans.
Can I run two showers at once on a tankless?
Yes, with the right size unit. We size based on simultaneous fixture demand and incoming water temperature in winter. Holliston groundwater is cold in February, which is the worst case we design for.
Do you service tankless water heaters you didn't install?
Yes. We service Navien, Rinnai, Rheem, and most major brands regardless of who installed them. Common service includes flushing, ignition fixes, error-code diagnosis, and venting repairs.
Ready for endless hot water?

Get your tankless quote.

Call Bob or Bobby for a same-week site visit and a flat written quote.

☎ Call 508-429-2888