Conversion Guide · Duluth & Superior
Boiler to heat pump conversion in the Twin Ports.
Replacing an old boiler with a cold-climate heat pump is one of the highest-ROI upgrades available to Duluth and Superior homeowners. You cut heating costs, add air conditioning to a house that's never had it, and stack a federal tax credit up to $2,000 with Minnesota Power, Xcel Energy, and Wisconsin Focus on Energy rebates worth $1,000–$1,500+. Most historic Twin Ports homes keep the existing boiler as backup heat, so there's no need to tear out cast-iron radiators.
Why Twin Ports homes are great candidates
Adds A/C without ductwork
Most historic Duluth and Superior homes were built for hydronic heat and have no ducts. Ductless mini-split heat pumps add quiet, zoned cooling room by room — no demo, no soffits.
Cuts heating costs 30–50%
Cold-climate heat pumps deliver 2–3× more heat per dollar than old atmospheric boilers, especially when paired with a smart dual-fuel control that picks the cheapest fuel hour by hour.
Keeps the boiler as backup
We don't have to rip out cast-iron radiators. The boiler stays as deep-cold backup and a redundant heat source — best of both worlds for a 100-year-old house.
Yes — cold-climate heat pumps actually work in Duluth.
- Cold-climate ASHPs deliver rated capacity to ~5°F and operate below −15°F.
- Dual-fuel pairing means the existing boiler (or a small gas furnace) only fires on the coldest 30–60 hours of the season.
- Ductless mini-splits add cooling without touching plaster walls, soffits, or chasing duct runs through a balloon-framed historic home.
- Variable-speed inverter compressors dehumidify in summer better than a single-stage central A/C.
Real Twin Ports conversion scenarios
1920s Duluth foursquare with cast-iron radiators
Keep the boiler. Add a 3- or 4-zone ductless mini-split system — living spaces and bedrooms get heating + cooling, the boiler covers the coldest 10–15 nights of the year.
East-end bungalow with old steam boiler
Replace the failing boiler with a centrally ducted cold-climate heat pump plus a high-efficiency gas furnace as dual-fuel backup. Adds whole-house A/C for the first time.
Superior duplex with hydronic baseboard
Ductless heads in each unit give tenants independent climate control and metered efficiency. Boiler stays as common-area backup heat.
How a Twin Ports conversion works
- Step 1
Load calculation & home walk-through
We do a Manual J on the home and look at zone-by-zone heat loss, existing radiator layout, electrical panel capacity, and where ductless heads or a slim-duct air handler can land discreetly.
- Step 2
System design
Most conversions land on either (a) ductless multi-zone mini-splits with the boiler retained for sub-zero backup, or (b) a centrally ducted cold-climate heat pump if there's attic/basement room for a small duct run.
- Step 3
Rebate-grade equipment selection
We spec AHRI-matched equipment that hits Xcel / Minnesota Power / Focus on Energy efficiency thresholds so every available rebate is on the table.
- Step 4
Install & commissioning
Clean installs with refrigerant line covers, proper condensate handling, and a smart thermostat or controller that automates the dual-fuel switchover point.
- Step 5
Rebate & tax-credit paperwork
We submit utility rebate forms and hand you the Manufacturer Certification Statement + itemized invoice for the federal 25C tax credit.
Stack the rebates
A boiler-to-heat-pump conversion in Minnesota or Wisconsin typically qualifies for three layers of incentive — and we handle the paperwork.
Program
Federal 25C tax credit
Up to $2,000
30% of qualifying project cost for cold-climate heat pumps meeting CEE efficiency tiers.
Program
MN utility rebates
Up to $1,200
Minnesota Power and Xcel Energy tiered rebates for ASHPs and ductless mini-splits, with bonuses for replacing electric resistance heat.
Program
WI Focus on Energy
Varies
Wisconsin rebates for Superior-area homes installing qualifying high-efficiency heat pumps.
Get a free conversion plan for your home.
We'll measure your home, design a system that fits a historic floor plan, and put the rebate math in writing before you decide.