Should I replace my gas wall heater with a same-size heat pump?
Not automatically. Wall heaters are often oversized for a tight cottage. We calculate each room’s load and typically find that a couple of small zones does the job.
Residential HVAC · Larkspur, CA
Residential HVAC & Heat Pumps in Larkspur, CA
Larkspur is warmer in summer and chillier at night than the Marin coast, and many homes still rely on wall furnaces. We replace them with right-sized heat pumps that heat and cool, designed from a room-by-room load.
Remodels · Retrofits · Heat Pumps · Multi-Zone Systems
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- 5.0 Google Rating 5.0 out of 5 stars
- Mitsubishi Electric Diamond Contractor
- C-20 + C-36 Licensed & Bonded
- Serving the Bay Area since 2015
Project fit
Larkspur work we do most
Small older houses, stair-access hillside lots and condos make up much of Larkspur. The services below match them.
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Old heaters
Wall and floor furnace replacement
Gas wall heaters and floor furnaces removed, openings closed, and a heat pump installed that also provides cooling.
Replacement & conversion -
No ducts needed
Ductless systems for cottages
Small indoor heads and thin line sets for houses with plaster walls and tight crawlspaces.
Ductless & multi-zone -
Shared walls
Condo and townhome heat pumps
Systems planned around HOA rules, balcony or roof limits and neighbor noise.
Heat pump installation -
Carry-in
Stair-access hillside installs
Equipment that can be hand-carried, with line sets routed around railings and retaining walls.
Heat pump installation -
Remodel
Additions and kitchen remodels
Mechanical planning for the new square footage so it does not overload the old system.
HVAC for remodels -
Manual J
Load calculations
A written Manual J behind the system we install, so capacity is set by real numbers.
Manual J load calculations
A comparable published job
Whole-home heat pump remodel
View project →
High-end residential remodel
Hearst Remodel
A Berkeley project with six indoor wall units on a finished older home shows how we route lines and place units on a constrained site, which is the same challenge many Larkspur retrofits present.
- Home type
- Existing home, remodel for sale
- System
- Fujitsu multi-zone ductless heat pump
- Mechanical scope
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- · Six indoor wall units
- · Two outdoor units
- · Wall-mounted outdoor brackets
- · Refrigerant routing and field coordination
Challenge
- Existing older home with limited equipment placement options
- Outdoor units required side-yard wall bracket mounting
- Finish-sensitive interior installation
- Coordination with the general contractor’s remodel schedule
3RDGEN scope
- Six-zone ductless heat pump installation
- GC-led remodel coordination
- Permit and inspection support
- Startup as part of the completed remodel scope
Outcome
The six-zone Fujitsu ductless system was installed, permitted, inspected, and completed as part of the home’s remodel-for-sale scope — delivering zoned heating and cooling without a conventional ducted retrofit.
Representative example from a Berkeley, CA remodel, not a project in this city. Photos and full details on the project page.
View projectLocal projects
Heat pump & HVAC installs for Larkspur homes
Recent installs by the 3rdGen crew that serves Larkspur: ducted and ductless heat pumps, air handlers and ductwork.
Warm days, cold nights
Larkspur’s temperature swings reward a heat pump that runs steady and small
Design conditions here are about 35°F in winter and 88°F in summer, with a daily range near 34°F. That means hot afternoons and quick cool-downs, which a modulating heat pump handles well.
Many Larkspur houses were built long before central air. A wall furnace and a window AC are common, and they leave temperature gaps room to room. A zoned heat pump layout closes those gaps.
Parts of town are near creeks and low ground, so we raise outdoor units and keep electrical connections high where it makes sense.
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Older cottages
Little or no ducting, plaster walls and low crawlspaces push us toward ductless or small-duct designs.
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Stairs and paths
Hand-carry access limits equipment size and affects how lines are run.
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Condos and HOAs
Outdoor placement often needs board approval before any work starts.
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Low-lying lots
We consider stands and brackets so equipment stays above likely water levels.
HVAC design in Larkspur
Larkspur: sheltered, warm in summer, and full of homes that were never designed for ducts
Larkspur sits between Mount Tamalpais and the bay, so it is protected from the fog that cools towns on the coast. Summer afternoons run hot, winter mornings run cold, and a lot of older homes handle both with a wall furnace and a window AC. That is a good case for a heat pump.
Design climate · Title 24 Climate Zone 2
- Winter design temp
- 35°F
- Summer design temp
- 88°F
Larkspur’s Manual J design conditions are about 35°F for heating and 88°F for cooling, with a daily temperature swing around 34°F. That swing means big temperature drops after sunset, so well-insulated, right-sized equipment holds comfort better than a large unit cycling on and off.
ACCA Manual J design data · Larkspur (ACCA micro-climate)
Larkspur housing, in practice
Older cottages and small houses around downtown often have raised floors and little or no ducting. Wall furnaces, floor furnaces and baseboard heaters turn up regularly.
Hillside homes reached by stairs and paths are part of Larkspur’s character. Equipment has to be carried in by hand, so weight and size matter in the choice.
Condominiums and townhomes, including newer buildings near Larkspur Landing, usually have strict limits on where outdoor equipment can go and may need HOA approval before work starts.
Start with Manual J before swapping a wall furnace
Replacing a 30,000 BTU wall heater with a similarly sized heat pump would overshoot a tight cottage. We calculate each room’s load first, and often find that two or three small zones cover the whole house.
Hot afternoon, cold evening
A 34°F daily range means rooms swing quickly. Manual S selection favors variable-speed equipment that can run steadily at low output rather than cycling hard in the evening.
Flood-aware equipment placement
Parts of Larkspur lie near creeks and low areas. We discuss elevating outdoor units on stands or brackets and keeping electrical connections above likely water levels.
Carry-in access
On stair-access lots, we pick components that two technicians can move without a crane and design line sets that clear railings and retaining walls.
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Wall and floor furnace replacement
Take out an old gas wall unit or floor furnace and add efficient heating and cooling with a heat pump.
Replacement & conversion → -
Ductless heat pumps for cottages
Compact multi-zone systems that avoid tearing into plaster and cramped crawlspaces.
Heat pump installation → -
Load calculations before you buy
A Manual J on your house so every bid is judged against the same numbers.
Manual J load calculations → -
Condo and townhome HVAC
Plans that respect HOA rules, shared walls, rooftop or balcony limits and noise.
Condo & townhome systems → -
Remodel and addition HVAC
Mechanical rough-in coordinated with your builder when a kitchen, bedroom or second story is being added.
HVAC for remodels → -
Warm-weather comfort and filtration
Cooling and higher-grade filtration for hot spells and smoky days.
Ventilation & IAQ →
Permits and utility basics in Larkspur
The City of Larkspur’s Building Division reviews and permits mechanical work. We supply the load report, equipment specs and a site plan that shows the outdoor unit location and clearances. Nearby Greenbrae and Kentfield are unincorporated and use Marin County’s building department.
MCE supplies electricity generation by default in Larkspur, with PG&E delivering it. State, regional and utility heat pump incentives change often, so we check current options when scoping your work instead of promising specific amounts. More background is on our rebates page.
Where we work near Larkspur
Downtown Larkspur, the hillside streets above it and Larkspur Landing, plus Corte Madera, Greenbrae, Kentfield and San Rafael.
Homeowner reviews
Trusted by Bay Area Homeowners
5.0
5 out of 5 stars from 207 Google reviews 207 Google reviews
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Mitsubishi mini-split installed with outstanding care. Indoor and outdoor units done right. High efficiency meant a meaningful federal tax credit too.
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Expand
Devin and his crew did a fantastic job installing AC for our whole house. High quality Mitsubishi equipment and a clean installation throughout.
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Devin is meticulous, methodical, and knowledgeable. Professional crew and a heat pump install we trust completely.
Photos from the installs above
Read all 207 reviewsProcess
How a Larkspur retrofit goes from first call to finished
Retrofits in older homes involve surprises. We walk the house first so those surprises show up before the quote.
01 — House walk
We look at your current heaters, the crawlspace or attic, the panel and the access path.
02 — Manual J loads
Calculated room by room, since cottages often split into a handful of small zones.
03 — Manual S and D
Pick equipment to the load and design duct or line routes through the spaces that exist.
04 — Permit and HOA
City of Larkspur mechanical permit, plus any HOA approval for condos and townhomes.
05 — Installation
Old heaters removed, gas capped, new equipment and electrical installed.
06 — Commissioning
Airflow, charge and controls verified and explained.
Finishing the job properly
What happens after the old heater comes out
A Larkspur retrofit often means patching a wall, running new lines and adding a circuit. We schedule these together so the house stays livable.
We finish by testing the system and walking you through the remote and schedules.
Tell us about the project-
Heater removal
Old gas unit disconnected, capped and the opening closed.
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New lines or ducts
Refrigerant lines or ducts run and sealed, with a condensate path.
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Circuits
Dedicated electrical added and permitted.
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Testing
Airflow, charge and controls verified.
Cost
What a Larkspur heat pump project costs: the variables
Replacing a wall furnace with one or two ductless heads is a very different job from converting a whole house. Number of zones, line set length, duct work, electrical upgrades, hand-carry access and HOA requirements decide the quote.
Scope Typical 3rdGen Project Range What drives it
Ducted heat pump, existing ducts usable $20k–$30k Equipment tier, capacity, controls, condenser location and access
Ducted heat pump + duct repair or resizing $25k–$45k Amount of ductwork replaced, crawlspace or attic access, return-air changes
Ductless multi-zone, 3–4 heads $25k–$40k Head type, line-set length, routing, concealment and finish conditions
Whole-home ducted + ductless combination $40k–$80k+ Multiple systems, zoning, ductwork, filtration, ventilation and architectural coordination
New construction system $20k–$50k+ Building size, system count, Title 24/design requirements and coordination with the build
ADU system $10k–$15k Zone count, head type, line-set routing, and whether the ADU shares the main house or stands alone
Electrical panel upgrade, when required $10k+ Service size, meter location, utility requirements and site conditions
Prices as of November 2026. Complex whole-home and design-build projects can exceed these ranges. Rebates and incentives may reduce your net project cost.
Project inquiry
Tell us about your Larkspur home
Share what heats it now, whether it is a house or a condo, and what is not comfortable. Photos of the heater and the outdoor space speed things up.
- Reviewed by a project lead, not a dispatcher
- We tell you if your scope is not a fit for us
- No high-pressure in-home sales appointment
Project Inquiry
Inquiry Sent
Thanks — your project details are on their way to 3rdGen. We’ll review them and follow up about the next step.
Project teams
Alongside contractors on Larkspur remodels
If a builder is adding a room or opening walls, that is the cheapest moment to run lines and ducts. We coordinate with them on timing and access so the HVAC rough-in fits the schedule.
We work within existing project teams in Larkspur and across Marin — or directly with homeowners when that is the right path.
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Architects
Mechanical systems coordinated around architecture, ceiling conditions, equipment locations, routing, and finish requirements.
Explore HVAC for architects -
General Contractors & Builders
Clear scope, scheduling, rough-in coordination, submittals, inspections, startup, and project handoff.
Explore HVAC for builders & GCs -
Mechanical Engineers
Field execution, equipment selection, controls coordination, submittals, installation, and commissioning aligned with the mechanical design.
Explore engineering coordination -
Homeowners
Already assembling your own project team? We can take ownership of the mechanical scope and coordinate directly with the other professionals involved.
Start a residential project
Mitsubishi Electric
Proud Mitsubishi Electric Diamond Contractor
As a Mitsubishi Electric Diamond Contractor, we design and install ducted, ductless, and multi-zone systems for Bay Area homes, with factory-trained crews and longer warranty options on qualifying residential installs.
Mitsubishi is not automatically the answer to every home. We start with what the project requires and recommend the system that makes sense.
12 Year Parts &
Compressor Warranty
12-year warranty
Extended parts & compressor coverage on qualifying Diamond installations.
Factory-trained crews
Ongoing manufacturer training on the latest hyper-heat systems.
Priority support
Direct factory escalation if anything ever needs attention.
FAQ
Common Questions
Larkspur-specific answers on wall heaters, condos, creeks and permits.
Is Larkspur hot enough to justify cooling?
The summer design temperature is around 88°F, with big daily swings. Many owners add cooling for the first time and find it useful. A heat pump gives heating and cooling from one system.
Can you install in a condo with an HOA?
Yes. We plan where the outdoor unit can sit, estimate sound and prepare drawings for board approval. Shared-wall construction also affects how lines are routed.
Do you do stair-access installs?
Yes. We choose equipment that can be hand-carried, plan the path in advance and route lines around railings and retaining walls.
What happens in a flood-prone part of town?
We raise the outdoor unit on a stand or wall bracket and keep electrical connections high. A site visit tells us how much that matters at your address.
Which agency permits heat pumps in Larkspur?
The City of Larkspur’s Building Division. Greenbrae and Kentfield are unincorporated and use Marin County, so the jurisdiction depends on your address.
Who supplies the electricity?
MCE is the default generation provider and PG&E delivers the power. Heat pump incentives from TECH Clean California, BayREN and the utilities vary over time, so we confirm what is available before you commit.
Nearby service areas
Heat pump and HVAC design near Larkspur
Project Inquiry
Inquiry Sent
Thanks — your project details are on their way to 3rdGen. We’ll review them and follow up about the next step.