Two programs pay for heat pumps in Wellesley, and the system in your basement today decides which one you apply to. Clement Boston Heat Pumps handles heat pump installation in Wellesley, MA, and we settle that question on the first visit, before any equipment is chosen.
Oil, propane and electric homes go through the town’s own light plant. Gas homes, about seven in ten, go through Mass Save.
Which rebate a Wellesley house qualifies for
Wellesley Municipal Light Plant supplies the town’s electricity, so Mass Save’s electric-side rebates don’t reach oil, propane or baseboard switches here. The light plant runs its own heat pump program, with tiers that follow how much of the house the system heats.
Oil, propane and electric homes
The whole-home tier pays $8,500 when the old system is removed or decommissioned, and $6,500 when it stays in place. Partial-home pays $1,125 a ton up to $5,000. Basic pays $500 a ton up to $2,500, for small spaces under 500 square feet and for replacing an existing heat pump.
The sizing band decides the tier
To count as whole-home, the system has to meet 90% to 120% of the house’s heating load. Undersize it and the job drops to partial-home; oversize it and the equipment short-cycles on mild days. Our sizing guide explains how a room-by-room load calculation reaches the number.
Gas homes apply to Mass Save
National Grid supplies Wellesley’s gas and sponsors Mass Save, so a gas-heated home applies there. The whole-home tier needs cold-climate listed equipment, an installer in Mass Save’s network, the old system out and proof of weatherization. We install qualifying equipment as a participating contractor; the rebate guide lists every condition.
Big houses and colder nights
About 82% of Wellesley homes are detached houses, and a third were built before 1940. Many are large, and the town sits inland, where the coldest nights fall well below what the harbor sees.
Sizing for the inland cold
Norwood Memorial Airport, the nearest inland station, averages about five nights a year at or below 0°F; Logan averages under one. We size at Wellesley’s design temperature and read each unit’s output at 5°F, not its nameplate. See do heat pumps work in Massachusetts.
Older houses heated by radiators
Near Wellesley Square and in Wellesley Hills, many colonials and Tudors heat with a boiler and have no ducts. The plan is an attic air handler for the bedrooms and a basement unit for the first floor, joined through a closet chase. See boiler to heat pump conversion and heat pumps in old houses.
Postwar houses with a furnace
Houses from the 1950s on more often have a forced-air furnace and central air. Those ducts can carry heat pump air once we’ve measured static pressure and checked the return size; see furnace to heat pump conversion.
Gas heats most of Wellesley
About 70% of Wellesley homes heat with gas, 15% with oil and 13% with electricity. Gas costs the least per delivered BTU, so the case for switching rests on more than the heating bill.
- Gas homes switch for central cooling, a furnace near the end of its life, or one system for both seasons. Some keep the furnace as backup on a dual fuel system. We compare costs on your actual rates; see heat pump vs gas furnace.
- Oil homes gain the most on running cost, and the tank leaves with the boiler; see oil to heat pump conversion.
- Electric heat homes, often condos off Route 9, get two to three units of heat per kilowatt-hour where baseboard gives one.
On light plant power, the state’s seasonal heat pump rates don’t apply; those come from Eversource, National Grid and Unitil. The running-cost math in your estimate uses the light plant’s own rates.
Should the old boiler stay as backup?
On the light plant’s whole-home tier, keeping the old system costs you $2,000 of rebate: $6,500 instead of $8,500. That gap often settles a question owners expect to be harder.
When it comes out
A cold-climate system sized inside the band carries the house on its own, with electric backup strips locked out above a set outdoor temperature. Taking the boiler out frees basement space and ends the oil delivery and tank inspection. We remove the tank under the fire department’s permit; see oil tank removal.
When it stays
Some owners want a second heat source through the first winter, or have a recently replaced boiler with years left in it. Then the lower tier applies, and we wire the controls so the heat pump runs first and the boiler only picks up below a temperature you choose. The backup heat guide explains the settings.
What Wellesley permits and Wellesley Municipal Light Plant rebates involve
The town’s building department issues the permits, and the exact set is confirmed per address: electrical, mechanical for ducts and equipment, and building when walls open.
| What | The Wellesley figure |
|---|---|
| Electric utility | Wellesley Municipal Light Plant |
| Gas utility | National Grid |
| Light plant whole-home tier | $8,500 with the old system removed, $6,500 if it stays |
| Whole-home sizing band | 90% to 120% of the heating load |
| Outside the light plant program | New construction and additions of 500 sq ft or more |
| Energy code | Specialized stretch code since January 1, 2024 |
| Heating fuel | Gas 70.1%, oil 15.0%, electricity 12.8% |
Our typical range for a whole-home system on ducts we can reuse is $15,000 to $28,000 and up before rebates, and $20,000 to $40,000 and up with new ductwork. The cost guide explains what moves a Wellesley price within those ranges.
An Wellesley job, week by week
The first visit sets the rebate route as well as the equipment, because the sizing band and the fate of the old system both decide which tier you reach.
- Load calculation room by room, so the system lands inside the 90% to 120% band.
- Duct and panel check: static pressure, return size and leakage, plus the panel’s spare capacity.
- Written estimate listing equipment with its capacity at 5°F, duct work, electrical, permits, the rebate tier and the price.
- Install and commissioning: nitrogen pressure test, vacuum below 500 microns, charge by weight, measured airflow, and the backup heat lockout recorded.
If you live just over the line, our pages for Needham, Natick and Newton cover towns on Mass Save electric sponsors instead.