10 Common Heat Pump Mistakes That Are Costing You Money (And How to Fix Them)

Heat pumps are the most efficient way to heat and cool your Bay Area home—when used correctly. Unfortunately, many homeowners unknowingly make mistakes that slash efficiency, spike utility bills, and shorten equipment life.

After 20+ years of heat pump installations and service calls throughout Contra Costa and Alameda counties, we've seen the same mistakes again and again. Here's how to avoid them.

Mistake #1: Using Emergency Heat as Your Primary Heat Source

The problem: Many homeowners don't understand what "EM HEAT" actually does. They think it's a turbo boost for cold days. It's not.

Emergency Heat completely bypasses your heat pump and runs expensive electric resistance heating strips instead. These strips cost 2-3x more to operate than your heat pump.

The numbers: In the Bay Area with PG&E rates around $0.40/kWh:

• Heat pump heating: ~$0.12-0.15/hour
• Emergency heat: ~$0.40-0.60/hour

A winter spent on Emergency Heat can add $400-800 to your electricity bill.

How to fix it:

1. Only use EM HEAT when your heat pump is actually broken and you're waiting for service
2. For normal operation, keep thermostat on regular "HEAT" mode
3. Your system automatically engages auxiliary heat when outdoor temperatures drop low enough—you don't need to do it manually

Related: Do I Need a Special Thermostat for a Heat Pump? explains how smart thermostats manage auxiliary heat efficiently.

Mistake #2: Making Large Temperature Setbacks

The problem: Dropping your thermostat 10°F at night works great with a gas furnace (it recovers quickly). With a heat pump, large setbacks trigger backup electric heat during recovery—losing all your savings.

Why this happens: Heat pumps deliver heat gradually. When you wake up and crank the thermostat from 62°F to 72°F, the system can't recover fast enough using the heat pump alone. The thermostat calls for auxiliary heat to speed recovery—and suddenly you're paying furnace rates for electric resistance heat.

The math: If your setback triggers 2 hours of auxiliary heat every morning, that's:

• 2 hours × $0.50/hour × 150 days = $150/year wasted

How to fix it:

1. Limit setbacks to 2-4°F maximum with heat pumps
2. Use a smart thermostat with "Heat Pump Adaptive Recovery" (Ecobee has this feature)
3. Program gradual temperature changes instead of sudden jumps
4. Or skip setbacks entirely—heat pumps are efficient enough that steady temperatures often cost less

Mistake #3: Ignoring Dirty Filters

The problem: A clogged filter is the #1 cause of preventable heat pump problems. Yet we regularly find filters that haven't been changed in 6-12 months.

What happens with a dirty filter:

• Airflow drops 20-50%
• System runs longer to achieve the same temperature
• Efficiency drops 5-15% (costing $100-200/year)
• Evaporator coil can freeze
• Compressor works harder and wears faster
• Indoor air quality suffers

How to fix it:

1. Check filters monthly during heavy-use seasons
2. Replace every 1-3 months (more often with pets or allergies)
3. Use quality pleated filters (MERV 8-11 for most homes)
4. Consider a filter subscription so you never forget
5. If using reusable filters, wash monthly and replace annually

Pro tip: Set a recurring phone reminder on the first of each month to check your filter.

Mistake #4: Blocking the Outdoor Unit

The problem: Heat pumps need adequate airflow around the outdoor unit to work efficiently. We regularly see units surrounded by shrubs, covered with debris, or placed too close to walls.

Common airflow blockers:

• Overgrown landscaping within 2 feet
• Leaves, grass clippings, and debris
• Decorative fencing or enclosures
• Snow buildup (rare in Bay Area, but happens in hillside communities)
• Stored items like bikes, grills, or trash cans

Why it matters: A blocked outdoor unit can reduce efficiency by 10-25% and cause the compressor to overheat. In extreme cases, it triggers safety shutdowns or permanent damage.

How to fix it:

1. Maintain 2 feet of clearance on all sides of the outdoor unit
2. Trim shrubs and vegetation regularly
3. Keep the area clear of leaves and debris
4. Never stack anything against the unit
5. If you have a fence or screen, ensure it allows plenty of airflow

Mistake #5: Covering the Outdoor Unit in Winter

The problem: Some homeowners cover their heat pump with a tarp or cover during winter, thinking they're protecting it. This is a major mistake.

Why it's wrong: Heat pumps run year-round—they heat your home by extracting warmth from outdoor air. Covering the unit:

• Blocks airflow needed for heating operation
• Traps moisture and accelerates corrosion
• Can cause the unit to overheat
• Voids warranties if damage occurs

How to fix it:

1. Never cover a heat pump (unlike window AC units, which should be covered)
2. Clear snow or ice from the unit if necessary (gently, without damaging fins)
3. Ensure the defrost drain is clear
4. If you have a heat pump AND a separate AC, only the AC can be covered in winter

Mistake #6: Setting the Wrong Auxiliary Heat Threshold

The problem: Your thermostat has a setting for when auxiliary heat kicks in—typically based on outdoor temperature. If this threshold is set too high, you're running expensive backup heat on mild Bay Area nights.

Example: If your aux heat threshold is set to 40°F, and your area sees many nights between 35-45°F, you're using auxiliary heat constantly. Modern heat pumps work efficiently well below freezing—you probably don't need backup heat until 25-30°F.

Bay Area context: Our winter lows rarely drop below 35°F. A properly sized heat pump should handle 90%+ of our winter without auxiliary heat. If your aux heat runs frequently, something's wrong.

How to fix it:

1. Check your thermostat's auxiliary heat threshold setting
2. Set it to 30-32°F for most Bay Area locations
3. For hillside communities (like Orinda or Moraga), consider 28-30°F
4. If you're unsure, ask your HVAC technician to optimize settings

Related: Do Heat Pumps Work in Cold Weather? explains how modern heat pumps maintain efficiency in winter.

Mistake #7: Closing Vents in Unused Rooms

The problem: Closing vents to "save energy" in unused rooms actually makes your heat pump work harder and less efficiently.

Why it backfires:

• Heat pumps are sized for your whole house
• Closing vents increases duct pressure
• Higher pressure makes the blower work harder
• Can cause air leaks in ductwork
• Leads to uneven temperatures and comfort complaints

How to fix it:

1. Keep all vents open at least 75%
2. If some rooms are consistently too hot/cold, the problem is duct design—not vent closure
3. Consider a ductless mini-split for problem rooms
4. Have ductwork evaluated if closing vents is tempting

Mistake #8: Skipping Annual Maintenance

The problem: Heat pumps need professional maintenance at least once per year. Unlike furnaces (which many homeowners skip for years), heat pumps have more components that degrade without service.

What happens without maintenance:

• Refrigerant leaks go undetected (efficiency drops, compressor damage)
• Coils get dirty (efficiency drops 10-20%)
• Electrical connections loosen (fire risk, component failure)
• Moving parts wear out faster
• Defrost cycle may malfunction
• Warranty may be voided

How to fix it:

1. Schedule professional maintenance twice yearly (spring for cooling, fall for heating)
2. At minimum, get annual maintenance before winter
3. Sign up for a maintenance plan (saves money vs. individual visits)
4. Between visits: check filters, clear debris, listen for unusual sounds

What professional maintenance includes:

• Refrigerant level check
• Coil cleaning
• Electrical inspection
• Thermostat calibration
• Defrost cycle test
• Safety inspection

Mistake #9: Running the Fan Continuously

The problem: Some homeowners set the thermostat fan to "ON" instead of "AUTO," thinking it improves air circulation. With a heat pump, this can cause comfort and efficiency problems.

Issues with continuous fan operation:

• In heating mode, the fan blows air that feels cool between heating cycles
• Increases electricity consumption by $5-15/month
• Can pull humid outdoor air through the system in summer
• Wears out the blower motor faster

When "ON" is appropriate:

• Homes with air quality issues needing continuous filtration
• Homes with zoning systems designed for continuous fan
• If recommended by your HVAC contractor for a specific reason

How to fix it:

1. Set fan to AUTO for most situations
2. If you want better air circulation, use ceiling fans instead
3. If air quality is the concern, consider an air scrubber or purifier

Mistake #10: Ignoring Strange Sounds or Performance Changes

The problem: Heat pumps make various normal sounds, but new or unusual noises often indicate developing problems. Many homeowners ignore these warning signs until complete failure.

Normal sounds:

• Whooshing when switching modes
• Click at startup and shutdown
• Defrost cycle sounds (brief hissing, fan changes)
• Low hum during operation

Warning sounds (call for service):

• Grinding or metal-on-metal
• Squealing or screeching
• Loud banging or clanking
• Constant clicking
• Hissing when not in defrost

Performance warning signs:

• Higher bills without usage change
• Rooms not reaching set temperature
• System running constantly
• Frequent cycling on and off
• Ice on outdoor unit (outside of defrost)
• Burning smell

How to fix it:

1. Don't ignore new sounds—call for service promptly
2. Track your energy bills month-over-month
3. Note any comfort changes and report them to your technician
4. Early diagnosis prevents expensive repairs

Bay Area-Specific Considerations

Our Mild Climate = Special Opportunities

The Bay Area's mild climate means heat pumps work at peak efficiency here more than almost anywhere else in the country. But it also means:

• Auxiliary heat should rarely run (if yours runs often, something's wrong)
• Emergency Heat is almost never needed (our coldest nights are above heat pump capability)
• Year-round operation (unlike cold climates where heat pumps hibernate)

PG&E Rates Make Efficiency Critical

At $0.40+/kWh, every efficiency loss hits your wallet hard:

• A 10% efficiency loss = $100-200/year extra
• Using Emergency Heat unnecessarily = $400-800/year extra
• Dirty filters + poor maintenance = $150-300/year extra

Total potential savings from avoiding these mistakes: $500-1,000+ per year

Microclimates Matter

Bay Area microclimates affect heat pump operation:

• Coastal areas (fog, mild temperatures): Ideal for heat pumps
• East Bay hills (cooler nights, more temperature swings): May need lower aux heat threshold
• Inland valleys (hotter summers, cooler winters): Size matters more

Heat Pump Maintenance Checklist

Monthly:

• Check and replace air filter if dirty
• Clear debris from outdoor unit
• Check thermostat is in correct mode

Quarterly:

• Inspect outdoor unit coils for dirt/debris
• Check clearance around outdoor unit (2+ feet)
• Listen for unusual sounds during operation
• Verify all vents are open

Annually (Professional Service):

• Refrigerant level check
• Coil deep cleaning
• Electrical inspection
• Thermostat calibration
• Defrost cycle test
• Blower inspection
• Ductwork inspection

When to Call a Professional

Call immediately if:

• Ice buildup on outdoor unit that doesn't melt during defrost
• Burning smell from indoor or outdoor unit
• System won't turn on
• Refrigerant leak (hissing sound, ice on lines)
• Electrical issues (breaker tripping, sparks)

Schedule service soon if:

• Unusual sounds developing
• Efficiency noticeably dropping
• Comfort complaints increasing
• It's been more than a year since maintenance

Get Your Heat Pump Running at Peak Efficiency

Galaxy Heating & Air Conditioning provides expert heat pump service throughout the Bay Area. Whether you need maintenance, repairs, or just want your system optimized, we can help.

What we offer:

• Free system assessment (we'll identify any issues affecting efficiency)
• Professional maintenance (complete service per manufacturer specifications)
• Thermostat optimization (we'll set aux heat thresholds correctly for your location)
• Energy savings analysis (we'll show you exactly where you're losing money)
• Repair services (NATE-certified technicians, same-day emergency service)

Call (925) 578-3293 or schedule online.

We serve: Walnut Creek, Concord, Pleasant Hill, Lafayette, Orinda, Moraga, Danville, Alamo, Oakland, Berkeley, Alameda, and throughout the Bay Area.

Our promise: We'll help you get maximum efficiency and comfort from your heat pump—and help you avoid the costly mistakes we see every day.

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Galaxy Heating & Air Conditioning | CSLB License #1076868 (C-20 HVAC, C-10 Electrical, B General Building)