Many Maine homeowners do not have to make an immediate all-or-nothing choice between oil and heat pumps. A properly designed cold-climate heat pump system can become the home’s primary heat source while an existing boiler remains available for true emergencies.
The right decision depends on the home’s heating load, room layout, domestic hot-water setup, condition of the oil equipment, outage planning and rebate requirements. This guide explains when it may make sense to replace oil heat with heat pumps in Maine—and when keeping the boiler as backup may be practical.
The Short Answer: Primary Heat Is Different From Backup Heat
A homeowner can keep an oil boiler in the basement without using it as the everyday heating system. When heat pumps are designed to serve the whole home, the boiler can be turned down or off and reserved for situations such as heat pump service, an electrical outage where the boiler can run from a generator, or another genuine emergency.
Option 1: Replace Oil as the Primary Heat Source
In this approach, cold-climate heat pumps are selected and placed to serve the home’s normal heating needs throughout the Maine winter. The oil system is either retired or left in place only for emergency use.
Potential Advantages
- Substantially reduced oil consumption
- Heating and air conditioning from one system
- Less exposure to oil-price swings
- Possible eligibility for whole-home rebates
- No routine boiler operation when the heat pumps cover the load
Planning Requirements
- Accurate heating-load calculations
- Enough low-temperature heat pump capacity
- Coverage for closed rooms and multiple levels
- Proper electrical capacity and dedicated circuits
- A plan for domestic hot water and emergencies
Whole-home performance depends on system design. Installing one indoor unit in the living room is not the same as designing heat pumps to serve every occupied area. Read our guide, Can Heat Pumps Heat a Maine Home All Winter?, for more detail about sizing, placement and cold-weather output.
Option 2: Keep the Oil Boiler for Emergency Backup
Some homeowners feel more comfortable keeping a working boiler even when the heat pumps become the primary system. That can be reasonable, particularly when the boiler is in good condition, provides domestic hot water or can operate from an existing generator that cannot power the entire heat pump system.
However, keeping the boiler as backup does not mean setting both systems to compete with each other every day. If the boiler thermostat is calling for heat before the heat pumps satisfy the space, the home may continue burning oil and never realize the expected savings.
When Keeping the Boiler May Make Sense
The Boiler Also Makes Domestic Hot Water
Some oil boilers produce household hot water in addition to space heating. Turning off or removing that boiler requires a separate hot-water plan. Options may include a heat pump water heater, electric water heater or another correctly sized system. The right choice depends on household demand, available space, electrical capacity and equipment condition.
Your Generator Can Run the Boiler but Not the Heat Pumps
Heat pumps require electricity. During an outage, a smaller generator may be able to operate boiler controls and circulators but not several heat pump outdoor units. In that situation, the boiler may provide a useful emergency-heating option. A licensed electrician should evaluate the actual generator capacity, transfer equipment and connected loads.
The Home Is Being Converted in Stages
A homeowner may begin with heat pumps serving the most-used rooms and add additional zones later. During a staged conversion, the boiler may still be needed for rooms that do not yet have enough heat pump coverage. This differs from a completed whole-home design.
The Boiler Protects an Isolated Area
Basements, additions, bathrooms or closed bedrooms may have heating needs that are not met by a nearby wall-mounted unit. Those areas should be addressed in the heat pump design. Until they are, the existing system may still serve a legitimate purpose.
When Retiring the Oil System May Make Sense
Once heat pumps are correctly designed to serve the entire home, maintaining an aging oil system may become an unnecessary expense. Homeowners may consider retiring it when:
- The boiler or oil tank is near the end of its useful life.
- The heat pumps have enough verified cold-weather capacity for the home.
- Every important room has an adequate heat-distribution plan.
- Domestic hot water is supplied by another system.
- The homeowner has an acceptable outage and emergency-heating plan.
- Annual boiler cleaning, repairs and oil deliveries are no longer worthwhile.
Oil equipment and tanks should not simply be disconnected or abandoned without considering applicable safety, fuel-storage and disposal requirements. The heat pump contractor can help define the new heating plan, while qualified oil-system professionals should handle work involving the boiler, burner, oil lines and tank.
How Efficiency Maine Rebates Affect the Decision
Efficiency Maine’s whole-home heat pump rebates are intended for customers who will use heat pumps as their primary heating system. Current program rules include equipment, sizing, installation and existing-heating-system requirements.
An existing furnace or boiler may remain available for emergency backup, but homeowners should not assume that everyday dual-system operation will satisfy the whole-home program. Eligibility must be confirmed using the current rules before finalizing the installation or operating plan.
Visit BANN’s Maine heat pump rebate guide for more information. Incentives and requirements can change, so confirm the current program at the time of your estimate.
Will Heat Pumps Cost Less to Operate Than Oil?
They often can, but the result depends on the home’s heat loss, system efficiency, electricity rates, oil prices and how the equipment is operated. The greatest oil reduction usually comes when the heat pumps provide the normal heat instead of being used only during mild weather.
See our detailed comparison of heat pumps versus oil heating costs in Maine. For project-planning information, read what affects heat pump installation cost in Maine.
Five Questions to Answer Before Making the Change
- Will the heat pumps serve the whole home or selected rooms? The required equipment and backup plan depend on the intended coverage.
- What is the home’s peak heating load? A whole-home system needs enough capacity at Maine’s winter design temperature.
- How is domestic hot water produced? A boiler that makes hot water cannot be removed without replacing that function.
- What is the outage plan? Consider generator capacity, wood heat, emergency space heating and vulnerable plumbing.
- What do the current rebate rules require? Confirm eligibility before choosing equipment or deciding how the boiler will operate.
One Team for Heat Pumps and Electrical Work
A whole-home conversion requires more than mounting indoor units. The project may need dedicated circuits, disconnects, panel-space evaluation or an electrical service upgrade.
BANN Home Electrical & Heat Pump Services completes both the heat pump installation and the required electrical work with its own team. Equipment, wiring, circuit protection and scheduling are coordinated through one contractor.
Learn more about BANN’s heat pump installation services in Maine. Financing may be available to qualified customers through our electrical and heat pump financing options.
Plan Your Move From Oil to Heat Pumps
BANN installs cold-climate heat pumps throughout Southern, Midcoast and select Central Maine communities. We can evaluate the home’s heating needs, room layout, existing oil system, electrical capacity and rebate considerations before recommending a whole-home or staged approach.
Request a Heat Pump Estimate Call 207-406-3918Frequently Asked Questions
Do I have to remove my oil boiler when installing whole-home heat pumps?
Not necessarily. A working boiler may remain available for emergency backup, domestic hot water or another specific need. The heat pumps can still be designed as the home’s primary heating system. Current rebate rules should be confirmed before deciding how the boiler will operate.
Can I run my oil boiler and heat pumps at the same time?
You can have both systems, but competing thermostat settings may cause the boiler to run before the heat pumps satisfy the space. That can reduce oil savings. The controls and operating plan should clearly identify which system provides primary heat.
Can heat pumps replace oil heat during a Maine winter?
Yes. Properly sized and designed cold-climate heat pumps can serve as the primary heating system through a Maine winter. The design must account for low-temperature capacity, the home’s heating load and heat distribution to all necessary rooms.
What happens to hot water if my boiler is turned off?
If the boiler currently produces domestic hot water, another water-heating system must take over that function before the boiler is retired. The options depend on household demand, space, plumbing and electrical capacity.
Does BANN complete the electrical work for a heat pump conversion?
Yes. BANN completes the heat pump installation and the necessary electrical work directly. We do not use a separate electrical subcontractor for the project.
Sources and program note: Heat pump operating and rebate guidance was reviewed from Efficiency Maine in September 2026. See Heat Pump User Tips, Homeowner Heat Pump FAQs and Whole-Home Heat Pump Rebates. Program rules and incentives are subject to change.