Tankless Water Heaters
Tankless (on-demand) water heaters heat water only when you open a tap. We install, repair and descale them, and tell you honestly when a tank is the better fit.
- Plumbing license
- 1310027098-PL-CMA licensed
- Shop
- 99 Felton StWaltham, MA
- Service call
- Free$89 fee only if you go ahead
- Workmanship
- 5 yearsNo labor charge
- Hours
- 8am–8pmMonday through Friday
How does a tankless water heater work?
A tank heater keeps a full tank hot all day. A tankless, or on-demand, water heater heats water only as it flows through the unit, so it doesn’t run out and doesn’t keep a tank of water hot all day. Units mount on the wall, freeing up floor space in the basement or utility room.
What does a tankless installation involve?
- An assessment of your current system, how much hot water your household uses at once, and your gas supply and venting.
- A right-sized system from trusted brands such as Rinnai, Navien and Noritz.
- Professional installation to code by a licensed plumber.
- Testing and a walkthrough of how to use and maintain the system.
What tankless problems do you fix?
- Fluctuating water temperatures
- Mineral buildup or clogged filters
- Ignition or burner problems
- No hot water or low flow rate
- System error codes
Regular descaling helps prevent future breakdowns, particularly in towns on hard well water. See which towns have hard water on our water filtration page.
What should I tell you when I call?
- Whether your current water heater is gas or electric
- How old it is
- How many people live in your home
5-Year Workmanship Guarantee
We stand behind how we do the work for five years. If something fails because of our installation or repair, we come back and correct it — no labor charge.
Covers Colt's workmanship. Parts carry the manufacturer's warranty. Excludes pre-existing conditions, customer-supplied fixtures, and freeze or misuse damage. Read the full termsCommon questions
Is a tankless water heater right for my house?
It makes sense for households that run out of hot water or want the floor space back, and less sense where the gas line or venting would need major work to support it. We'll price both options so you can compare.
Why does a tankless heater need descaling?
Minerals in the water build up inside the heat exchanger over time, which reduces flow and efficiency. How often depends on your water — towns on well water usually need it more often than towns on MWRA water.
What tankless problems do you repair?
Fluctuating temperatures, mineral buildup and clogged filters, ignition or burner faults, low flow or no hot water, and system error codes.
Related plumbing services
Water Heater Installation
Replacement and correct sizing, with code-compliant venting and expansion control.
Water Heater Repair
No hot water, sediment rumble, leaking tanks, thermostat and element faults.
Water Filtration
Softeners and filtration — for the towns that actually need them.
