The 5-Minute Checklist: Before You Call an HVAC Technician in the Bay Area

Save $150 in 5 Minutes

Your AC isn’t working. It’s 95°F in Walnut Creek. You’re about to call an HVAC technician for emergency service.

Wait. Before you spend $150-$300 on a service call, take 5 minutes to check these simple things.

40% of “no cooling” or “no heating” service calls we receive are fixed by one of these simple checks. You could save yourself money, time, and the wait for a technician.

This checklist is designed for Bay Area homeowners with zero HVAC knowledge. If you can change a light bulb, you can do these checks.

When to Use This Checklist

Use this checklist when:

• ✅ Your HVAC system won’t turn on at all
• ✅ Your thermostat display is blank
• ✅ Your system stopped working suddenly
• ✅ Your heat pump is blowing cold air in winter
• ✅ You just returned from vacation and nothing works
• ✅ After a power outage or storm

Skip this checklist and call immediately if:

• ❌ You smell gas (evacuate and call 911)
• ❌ Carbon monoxide detector is alarming (evacuate and call 911)
• ❌ You see smoke or flames
• ❌ You hear loud banging, screeching, or grinding
• ❌ Water is leaking around your furnace
• ❌ System works but makes concerning noises

For emergencies: Call (510) 391-5597 or 911 if life-threatening

The 5-Minute HVAC Troubleshooting Checklist

✓ Check #1: Thermostat Display (30 seconds)

Look at your thermostat:

Is the display blank or dim?

• If YES: Dead batteries (most common cause)
• If NO: Skip to Check #2

How to fix:

Step 1: Remove thermostat from wall

• Most pull straight off the base (gentle pull)
• Some have a release tab on bottom
• Be gentle—it’s just plastic clips

Step 2: Check for batteries

• Usually 2-4 AA or AAA batteries
• Located in back or battery compartment on side
• If no batteries: Your thermostat is hardwired (skip to Check #2)

Step 3: Replace batteries

• Use fresh alkaline batteries
• Match the +/- orientation exactly
• Don’t mix old and new batteries

Step 4: Reinstall thermostat

• Align with base plate
• Push gently until it clicks
• Display should light up immediately

Cost: $5-$10 for batteries vs. $150 service call

Bay Area tip: Coastal humidity can corrode battery contacts faster. If you live in San Francisco, Pacifica, or Half Moon Bay, change batteries annually even if they seem fine.

Did this fix it?

• YES: You just saved $150! Set your temperature and you’re done.
• NO: Continue to Check #2

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✓ Check #2: Thermostat Settings (60 seconds)

Your thermostat is on, but system still not working? Check these settings.

Verify these settings:

1. Mode Setting:

• Summer: Should be set to “COOL” (not HEAT, not OFF)
• Winter: Should be set to “HEAT” (not COOL, not OFF)

Common mistake: Left on wrong mode from last season

2. Temperature Setting:

• Cooling: Set at least 3-5°F BELOW current room temperature
• Heating: Set at least 3-5°F ABOVE current room temperature

Example:

• Room is 78°F
• Thermostat set to 76°F
• System won’t run (already above setpoint!)
• Fix: Set to 72°F

3. Fan Setting:

• Should be set to “AUTO” (not ON)
• If set to ON, fan runs constantly but may not heat/cool

4. Hold/Schedule:

• Make sure you’re not in a scheduled setback
• Press “Cancel Hold” or “Resume Schedule”
• Or manually override to desired temperature

Bay Area consideration: Mild spring and fall weather can make it hard to tell if system is working. On a 65°F day, your AC won’t run if set to 70°F—that’s normal, not broken.

Did this fix it?

• YES: Great! Just a setting issue.
• NO: Continue to Check #3

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✓ Check #3: Circuit Breakers (90 seconds)

Your HVAC system has TWO circuit breakers (many people only check one).

Where to check:

Breaker #1: Main Electrical Panel

• Usually in garage, basement, or exterior wall
• Look for breakers labeled:
  • “Furnace” or “Air Handler”
  • “AC” or “Air Conditioner”
  • “HVAC”
  • Sometimes unlabeled (in older panels)

Breaker #2: Disconnect Box (Outdoor AC/Heat Pump)

• Gray or metallic box on exterior wall near outdoor unit
• Usually within 10 feet of outdoor unit
• May have a pull-out fuse block or switch

How to check:

At main panel:

1. Open panel door
2. Look for tripped breaker (will be in middle position, not fully ON or OFF)
3. Turn fully OFF first, then fully ON
4. Should click into place firmly

At outdoor disconnect:

1. Open the disconnect box
2. Check if switch is ON
3. If it has pull-out fuses, remove and inspect for blackening or breaks
4. If fuse is blown, DON’T replace yet—call for service (indicates electrical problem)

Why breakers trip:

• Power surge (storms common in winter)
• Electrical short
• Overloaded circuit
• Failed component

Bay Area note: PG&E power fluctuations during wildfire season Public Safety Power Shutoff (PSPS) events can trip breakers when power restores. Check breakers after any outage.

If breaker trips again immediately:

• ⚠️ Don’t keep resetting it
• Indicates electrical problem or failed component
• Call for professional service: (510) 391-5597

Did this fix it?

• YES: Monitor to make sure it doesn’t trip again. If it does, call us.
• NO: Continue to Check #4

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✓ Check #4: Air Filter (60 seconds)

A dirty filter is the #1 cause of HVAC problems.

Where is your filter?

Common locations:

1. In return air grille (wall or ceiling, usually large grille)
2. In furnace cabinet (slot near blower, pull door off)
3. In return duct (near furnace)
4. In hallway (central return grille)

Not sure? Look for the largest grille in your home (usually living room or hallway).

How to check:

Step 1: Turn off HVAC system (thermostat to OFF)

Step 2: Locate and remove filter

• Pull grille off (may have clips or screws)
• Or open furnace door
• Or slide filter out of slot

Step 3: Hold filter up to light

• Can you see light through it clearly? GOOD
• Is it gray, dark, or clogged? BAD
• Can you barely see light? REPLACE

When filters need replacing:

Visual check:

• ✅ Clean: Can see through clearly
• ⚠️ Moderately dirty: Some dust accumulation
• ❌ Very dirty: Gray/black, can’t see through
• ❌ Extremely dirty: Dust caked on, sagging

Time-based (if you forgot to check):

• 1” disposable: Every 30-60 days
• 1” pleated: Every 60-90 days
• 4” media filter: Every 6-12 months
• HEPA filter: Per manufacturer (usually 6-12 months)

Bay Area wildfire season: During smoke events, check monthly and replace when dirty. Smoke clogs filters fast.

How to replace:

Step 1: Note filter size

• Written on frame (e.g., 16x25x1, 20x20x4)
• Take photo for reference

Step 2: Note airflow direction

• Arrow on filter frame
• Should point TOWARD furnace/air handler
• Take photo before removing

Step 3: Buy replacement

• Hardware store, Target, Amazon
• Match exact size
• MERV 8-11 recommended for most homes
• Cost: $5-$30

Step 4: Install new filter

• Arrow points toward furnace
• Filter fits snugly in slot
• No gaps around edges

Step 5: Turn system back on

Why dirty filters cause problems:

• Restricts airflow
• System overheats and shuts off
• Can damage blower motor
• Drastically reduces efficiency
• Can freeze evaporator coil

Did this fix it?

• YES: Excellent! Set a recurring reminder to check monthly.
• NO: Continue to Check #5

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✓ Check #5: Outdoor Unit (60 seconds)

Go outside and check your AC or heat pump unit.

Visual inspection:

1. Is it running?

• Set thermostat to cool (summer) or heat (winter, heat pump only)
• Go outside
• Listen for fan and compressor
• Should be humming and blowing air

2. Is it clear of debris?

• Check for leaves, cottonwood, grass clippings
• Look for bushes/plants touching unit
• Check for cardboard, plastic bags, or other objects

3. Is it blocked?

• Storage items against unit
• Tarp or cover (should be removed when operating)
• Fence or wall too close (needs 2 feet clearance)

Quick cleaning (if needed):

Step 1: Turn off power

• At thermostat: Set to OFF
• At disconnect box: Turn OFF

Step 2: Remove debris

• Pull out leaves, cottonwood, grass
• Trim vegetation to 2 feet clearance
• Remove any objects touching unit

Step 3: Hose off (gentle spray)

• Spray from inside out (pushes dirt out)
• Don’t use pressure washer
• Don’t bend fins
• Let dry 15-30 minutes

Step 4: Turn power back on

Bay Area considerations:

May-June (Cottonwood season):

• East Bay valleys get heavy cottonwood
• Clogs outdoor coils fast
• Check weekly during cottonwood season
• Can reduce efficiency 30-40%

Wildfire ash:

• After smoke events, outdoor coils accumulate ash
• Reduces efficiency
• Gentle hosing recommended
• Professional cleaning if heavy buildup

Did this fix it?

• YES: Great! Keep unit clear year-round.
• NO: Continue to Check #6

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✓ Check #6: Heat Pump “Emergency Heat” Setting (30 seconds)

⚠️ HEAT PUMP OWNERS ONLY (If you have a gas furnace, skip this)

The Problem:

Many Bay Area homeowners accidentally switch their heat pump to “Emergency Heat” or “Aux Heat” mode and don’t realize it. This:

• Uses expensive electric resistance heat (like a giant space heater)
• Can cost $200-$400/month in winter
• Bypasses efficient heat pump operation
• Should ONLY be used if heat pump is broken

How to check:

Look at thermostat display:

• Does it say “Emergency Heat,” “Aux Heat,” or “EM Heat”?
• If YES: You found the problem!

How to fix:

Step 1: Find the mode button

• Usually labeled “System,” “Mode,” or “Settings”
• May need to press and hold

Step 2: Switch to normal heat

• Change from “Emergency Heat” to “Heat”
• Or from “Aux Heat” to “Auto Heat”
• Exact wording varies by thermostat

Step 3: Confirm change

• Display should now show “Heat” only
• No “Emergency” or “Aux” indicator

When Emergency Heat IS needed:

• Heat pump completely broken
• Outdoor temps below 25°F (rare in Bay Area)
• Waiting for repair technician
• As temporary backup only

Bay Area reality: We rarely need emergency heat. If your system is working, it should be in regular “Heat” mode.

Did this fix it?

• YES: Your next bill will thank you! (Seriously, you’ll save hundreds)
• NO: Continue to Check #7

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✓ Check #7: Condensate Drain (60 seconds)

AC and high-efficiency furnaces produce water. If the drain is clogged, safety switches shut down the system.

Where to look:

Indoor unit (furnace/air handler):

• PVC pipe coming out of unit
• Usually white 3/4” plastic pipe
• Goes to floor drain, outside, or utility sink

What to check:

1. Is water overflowing?

• Puddle around indoor unit
• Drip pan full of water
• Water stains on floor

2. Is drain clogged?

• Remove drain cap (if accessible)
• Look for standing water
• Pour cup of water in—does it drain?

Quick fix (if safe to access):

Step 1: Turn off system

Step 2: Pour water in drain

• If it backs up: Clogged
• If it drains: Not the problem

Step 3: Try clearing (if accessible)

• Shop vac on drain opening
• Or blow compressed air (gently)
• Or use condensate drain tablets

When to call professional:

• Can’t access drain
• Backup won’t clear
• Water leaking from unit
• Afraid of making it worse

Bay Area homes: High humidity in coastal areas means more condensate. SF, Pacifica, Daly City homes should check drain annually.

Did this fix it?

• YES: Consider installing safety switch if you don’t have one.
• NO: Time to call a professional

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After the Checklist: What to Do Next

✅ If Something Fixed It

Congratulations! You saved $150-$300.

Now do this:

1. Make a note of what fixed it
2. Set a reminder to prevent it happening again
   • Batteries: Change annually
   • Filter: Check monthly
   • Outdoor unit: Check seasonally
3. Consider scheduling preventive maintenance to avoid future issues

Share your success: Tell your friends about this checklist. They’ll thank you when they save money too.

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❌ If Nothing Fixed It

You tried. Now it’s time to call a professional.

You’re not a failure—you’re smart:

• You eliminated simple causes
• You’ll give the technician better information
• You might save diagnostic time (and money)

When you call, mention what you checked: “I already checked batteries, breakers, and filter. The thermostat is on, set correctly, and has power, but the system still won’t run.”

This helps us:

• Bring the right parts
• Skip redundant checks
• Diagnose faster
• Potentially reduce service time

Call Bay Area Climate Control:

• Phone: (510) 391-5597
• Online: Request Service
• Emergency: 24/7 available

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When Professional Help is Worth It

Some things you SHOULD NOT DIY:

Never attempt:

• ❌ Electrical repairs beyond resetting breakers
• ❌ Refrigerant work (requires EPA certification)
• ❌ Gas line work (extremely dangerous)
• ❌ Heat exchanger inspection or repair
• ❌ Compressor replacement
• ❌ Ductwork modifications

These are professional jobs because:

• Safety hazards (electrocution, gas explosion, CO poisoning)
• Specialized tools required
• Licensing/certification required by law
• Warranty implications
• Potential to cause more damage

Trust your instincts: If something feels dangerous or beyond your skill level, call a professional.

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Preventive Maintenance: The Best 5 Minutes You’ll Spend

Monthly (5 minutes):

• Check air filter
• Listen for unusual sounds
• Verify thermostat works
• Check outdoor unit is clear

Seasonally (10 minutes):

• Change batteries before heating/cooling season
• Clean outdoor unit
• Check condensate drain
• Test system before you need it

Annually (hire professional - $150-$250):

• Complete tune-up and safety inspection
• Prevents 90% of breakdowns
• Extends equipment life 5-10 years
• Maintains efficiency (saves on energy bills)

ROI on maintenance:

• Annual tune-up: $200
• Average prevented emergency repair: $800
• Prevented system failure during heat wave: Priceless

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Bay Area-Specific Troubleshooting Tips

Coastal Homes (SF, Pacifica, Daly City)

Common issues:

• Battery corrosion from humidity
• Condensate overflow (high humidity)
• Outdoor unit corrosion
• Infrequent use problems

Extra checks:

• Clean battery contacts annually
• Check condensate drain before using AC
• Inspect outdoor unit for rust

East Bay Valleys (Walnut Creek, Livermore, Concord)

Common issues:

• Cottonwood clogs (May-June)
• Dust buildup on outdoor coil
• Filters clog faster
• Emergency heat accidentally enabled

Extra checks:

• Check outdoor unit weekly during cottonwood season
• Change filters every 30-45 days in summer
• Verify heat pump mode before heating season

Peninsula (San Mateo, Redwood City)

Common issues:

• Mild weather = uncertain if system is broken
• Infrequent use
• Smart thermostat WiFi issues

Extra checks:

• Test system monthly even when not needed
• Check WiFi connection on smart thermostats
• Verify thermostat schedule matches needs

South Bay (San Jose, Sunnyvale)

Common issues:

• High electricity costs from emergency heat
• Oversized systems short-cycling
• Tech workers troubleshooting too aggressively

Extra checks:

• Verify NOT in emergency heat mode
• Don’t over-troubleshoot (stick to basics)
• Check smart home automation hasn’t created conflicts

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The Honest HVAC Company Guarantee

Here’s our promise:

If you call us and we arrive to find it was just:

• Dead batteries
• Tripped breaker
• Dirty filter
• Wrong thermostat setting

We’ll fix it, show you how to prevent it, and charge our minimum service call ($95-$150).

But honestly? We’d rather you fix it yourself for free. This checklist exists because:

1. You save money
2. You get comfortable faster
3. You learn about your system
4. We focus on actual repairs

We want you to call when you genuinely need us—not for a $5 battery.

That said, we’re always here if you need us.

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Real Bay Area Success Stories

The $5 Fix (San Jose)

Problem: No cooling on 95°F day
Panic level: High
Checklist result: Dead AA batteries in thermostat
Fix time: 2 minutes
Cost: $5 for batteries
Saved: $150 service call + 4-hour wait for technician
Homeowner quote: “I felt silly but also pretty smart. Thanks for the checklist!”

The Filter Revelation (Oakland)

Problem: System running constantly, house not cooling
Symptom: High PG&E bills ($450/month)
Checklist result: Filter hadn’t been changed in 14 months (wildfire ash)
Fix time: 5 minutes to check, 30 minutes to buy filter
Cost: $18 for filter
Result: Next month bill: $240 (saved $210/month)
Homeowner quote: “I had no idea filters were that important.”

The Emergency Heat Mistake (Pleasanton)

Problem: $620 January heating bill (normally $180)
Symptom: House warm but bill shocking
Checklist result: Heat pump in “Emergency Heat” mode since November
How it happened: Accidentally pressed button while dusting
Fix time: 10 seconds
Cost: $0
Saved: ~$440/month for 3 winter months = $1,320
Homeowner quote: “I was about to replace my heat pump thinking it was broken!”

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Download This Checklist

Save this page (bookmark it or save PDF) and use it every time your HVAC system acts up.

Print-friendly version: Go to our website and download the 1-page PDF version to keep near your thermostat.

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When You DO Need to Call Us

We’re here for the real problems:

• Strange noises (banging, screeching, grinding)
• System freezing up
• Leaking refrigerant
• Electrical issues beyond breakers
• Gas smells or carbon monoxide concerns
• Annual maintenance and tune-ups
• System replacement consultations

Bay Area Climate Control
Carrier Factory Authorized Dealer
Serving the Bay Area Since 2010

Phone: (510) 391-5597
Emergency: 24/7 Available
Online: Request Service

Service Area:
Alameda • Contra Costa • San Francisco • San Mateo • Santa Clara Counties

Free Phone Diagnosis:
Call and describe your issue. We’ll walk you through this checklist over the phone. If it’s something simple, we’ll help you fix it for free. If it needs a technician, we’ll schedule you.

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Frequently Asked Questions

Q: Will trying these fixes void my warranty?
No. These are basic homeowner maintenance tasks. Checking batteries, filters, and breakers is expected and won’t void anything.

Q: What if I break something while checking?
These checks are very low-risk. The most “dangerous” thing you’ll do is pull off a thermostat (it just clips on). If you’re gentle and follow the steps, you won’t break anything.

Q: How do I know if I need a new HVAC system vs. a repair?
If your system is 15+ years old and needs a repair over $1,000, consider replacement. But try this checklist first—many “dead” systems just need batteries or a filter.

Q: Should I try YouTube videos for more advanced repairs?
No. Stick to this checklist. Anything beyond this requires professional training, tools, and licensing. YouTube can lead you astray.

Q: My system is brand new and not working. Should I still try this checklist?
Yes! New systems can have tripped breakers, wrong thermostat settings, or factory-shipped with covers still on outdoor units. Try the checklist first.

Q: Will HVAC companies get mad if I check these things first?
Good companies (like us) will appreciate it. Bad companies that rely on charging for simple fixes might be annoyed—which tells you everything you need to know.

Q: How often should I go through this checklist?
Only when something isn’t working. For prevention, just check the filter monthly and test your system seasonally.

Q: What’s the most common thing people miss?
The outdoor unit being covered or blocked. Homeowners winterize with covers and forget to remove them, or store things against the unit.

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Take 5 Minutes. Save $150. Stay Comfortable.

You don’t need to be an HVAC expert to solve basic problems.

Most homeowners fix their issue with this checklist. You probably will too.

And if you don’t? You’ll have valuable information when you call us, making the repair faster and potentially cheaper.

Ready to troubleshoot? Start at Check #1 and work your way down.

Still not working after all checks? We’re here to help: (510) 391-5597