The Three Types, Straight Up
Standard Tank (Gas or Electric)
Cost installed: $1,200-$2,000. Lifespan: 8-12 years. Common in Massachusetts's older triple-decker and colonial housing stock, where a straightforward swap is often the path of least resistance during a renovation.
Tankless (On-Demand)
Cost installed: $2,500-$4,500, often more in older homes needing a gas line or panel upgrade. Lifespan: 15-20 years. Space-saving in Massachusetts's smaller older homes, but New England's cold incoming water temperature means sizing needs more headroom than a manufacturer's default spec.
Heat Pump (Hybrid)
Cost installed: $2,500-$4,500 before rebate. Lifespan: 10-15 years. Uses roughly a third of the electricity of a standard electric tank. With Eversource and National Grid delivery rates both high in Massachusetts, the electricity savings show up faster here than in states with cheaper power.
| Type | Installed cost | After Mass Save rebate | Lifespan |
|---|---|---|---|
| Standard tank | $1,200-$2,000 | $1,200-$2,000 | 8-12 yrs |
| Tankless | $2,500-$4,500 | $1,750-$3,750 | 15-20 yrs |
| Heat pump | $2,500-$4,500 | $1,750-$3,750 | 10-15 yrs |
Sizing It Right
Tank sizing (by household size)
- 1-2 people: 30-40 gallons
- 3-4 people: 40-50 gallons
- 5+ people: 60-80 gallons
Tankless sizing (by flow rate)
Size to your peak simultaneous demand, not average use, and in Massachusetts specifically ask for the unit's rated output at New England's winter groundwater temperature, not the manufacturer's default spec.
What the Mass Save Process Actually Looks Like
The $750 rebate goes through your contractor's proposal, not a separate bank visit — confirm they're a Mass Save network participant before you sign anything, since that gates eligibility. Processing has run 8-12 weeks behind in 2024-2026 according to homeowner and news reports, and the program hired an outside company to clear the backlog. File early, keep every piece of paperwork, and don't assume the check arrives on the timeline a contractor quotes verbally.
What to Ask Before You Sign
- "Are you a Mass Save network-participating contractor?"
- "Is this specific model on the current Mass Save qualifying list?"
- "How long has your last few customers waited for the rebate check?"
- "What's the real installed cost after the $750 rebate?"
The One Number That Matters
A heat pump water heater in a typical Massachusetts home saves roughly $150-$250 a year in electricity versus a standard electric tank. Combined with the $750 rebate, payback on the price difference is usually 4-6 years.