24/7 Emergency Electrician · Pillar Guide

Emergency generator service, diagnose and run.

Same-day response when your generator won't start, transfer switch fails, or generator stops mid-event — diagnostic, repair, and restoration.

Written bySteven Lockhart

Reviewed byAlex Towery · C-10 #989290

Updated: June 2026 · Read: 7 min

11 yrsMarin electrical work

C-10CSLB licensed contractor

1st passInspection rate

48 hrTypical estimate turnaround

Key Takeaways

Most generator failures during outages trace to one of four causes: battery (most common), fuel supply (gas pressure or diesel quality), transfer switch (mechanical or controls), or engine condition (maintenance-related).
Generators that don't run regularly fail when needed — quarterly exercise is the single highest-value preventive measure for backup reliability.
PSPS events drive concentrated demand for emergency generator service — response times extend during widespread events; priority for life-safety contexts.
Most emergency repairs are straightforward (battery replacement, transfer switch troubleshooting, fuel supply correction) — full equipment replacement is rare in emergency response.
Maintenance contract customers get priority response and substantially faster diagnostic turnaround during PSPS events.

Towery Electric — Emergency Generator Service.

01 — OverviewWhat Emergency Generator Service actually covers in Marin.

Emergency generator service is the most frustrating moment in the standby generator value chain — the moment the grid goes down is when the generator is supposed to take over, and when it doesn't, you experience exactly the outage you bought equipment to prevent. The pattern is depressingly predictable: generator hasn't been exercised regularly, battery has self-discharged, or fuel supply has degraded, or transfer switch hasn't actuated in months — and the moment of need reveals the accumulated maintenance deficit.

We respond to generator failures specifically during outage events. Demand spikes during PSPS, atmospheric rivers, and widespread weather events; response times extend; we prioritize by criticality. Most emergency generator repairs are straightforward — battery replacement (most common), transfer switch troubleshooting, fuel supply correction, controls panel reset. Full equipment replacement during emergency is rare; most failures are remediable on-site within 2-3 hours of diagnostic response.

Definition

'Emergency generator service' covers the diagnostic and repair response when standby generators fail to operate during a grid outage event — failure to start, transfer switch malfunction, mid-event shutdown, load-carry failure.

The four common failure categories

Battery (most common, 40-50% of failures) — battery has self-discharged or aged out. Fuel supply (15-25% of failures) — natural gas pressure inadequate, propane tank empty, diesel quality degraded. Transfer switch (15-20% of failures) — mechanical or controls failure preventing actuation. Engine condition (10-15% of failures) — maintenance-related issues like oil, coolant, sensors.

Why quarterly exercise prevents most of this

Quarterly under-load exercise (30-60 minutes running at meaningful load) catches battery degradation early, exercises the transfer switch through actuation cycles, ensures fuel supply path is intact, and identifies engine condition issues before they become outage failures. Skipping exercise is the single largest factor in emergency generator failures.

For the broader context this guide supports, see our 24/7 Emergency Electrician overview.

Explore the Full Guide

Emergency generator work clusters by symptom and by failure category.

Three guides to read first

Most Common

Generator Won't Start at Outage

Diagnostic sequence for the most common emergency call — battery, controls, fuel supply.

Explore the guide →

Critical

Transfer Switch Failure Diagnosis

When the ATS won't actuate — mechanical vs controls vs sensor issues.

Explore → Prevention

Why Generators Fail When Needed

The pattern of accumulated maintenance deficit and how to prevent it through exercise and service.

Explore →

Browse the Full Library

By symptom

By cause

Transfer switch

By generator brand

02The four failure categories — diagnostic ordering.

When responding to a generator-won't-run call, the diagnostic sequence focuses on the most common causes first.

Battery (check first)

Most common cause — battery has self-discharged or aged out. Check battery voltage at controls panel; under 12.0V suggests battery failure. Most modern standby generators have battery health indicators in controls panel that flag battery issues weeks before actual failure (if anyone's watching).

Fuel supply (check second)

For natural gas: verify gas line valve open, check pressure at generator. For propane: verify tank not empty, check for leaks at connections. For diesel: check fuel quality (water contamination, microbial growth in long-stored fuel), verify pickup line not blocked.

Transfer switch (check third)

Verify ATS sensed utility loss and signaled generator to start. If ATS didn't sense outage, look at sensing inputs and controls. If ATS sensed outage but didn't transfer to generator, check actuator mechanism and contactor.

Engine condition (check fourth)

If battery, fuel, and ATS all check out: engine condition issues — oil low, coolant low, sensor fault, ignition issues (gas engines), injection issues (diesel). Less common but require maintenance-level diagnostic.

03Why PSPS events drive emergency demand.

Public Safety Power Shutoffs (PSPS) create demand concentration patterns that strain emergency service capacity. A typical multi-day PSPS event in Marin/Sonoma puts hundreds of generators into actual use simultaneously — and reveals every accumulated maintenance deficit at once. Customers who haven't exercised their generators discover battery failures; customers who haven't maintained fuel supply discover empty propane tanks or degraded diesel; customers who haven't had transfer switch service discover actuator issues.

We maintain dispatch capability specifically for PSPS events but realistic response times extend to 4-8 hours for non-life-safety generator failures during major events. Maintenance contract customers get priority response — typically 2-3x faster than non-contract during PSPS. The structural answer to slow PSPS response isn't faster emergency dispatch; it's better preventive maintenance so the emergency doesn't happen.

04What we typically carry for generator emergency calls.

Our service trucks are equipped specifically for generator emergency response.

Replacement batteries

Common generator battery sizes carried — covers 70-80% of emergency calls with immediate replacement capability. Including specialty AGM and gel-cell batteries used in newer generators.

Common ATS components

Replacement control modules and actuators for major brands. Many ATS failures are remediable with component-level replacement rather than full ATS swap.

Diagnostic equipment

Brand-specific diagnostic interface tools for Generac, Kohler, Cummins, Briggs. Allows fault code interpretation, controls reset, and configuration verification on-site.

Fuel testing capability

For diesel installations: water/contamination testing for fuel quality issues. For natural gas: pressure testing at generator connection to identify gas supply issues.

05Maintenance contract priority during PSPS.

We maintain a separate dispatch queue during PSPS events for maintenance contract customers. The structural difference: contract customers have known generator equipment (we maintain records), known recent service history (we know exercise dates and any flagged issues), and known facility context (we know what's critical and what's not). This combination enables faster diagnostic on emergency calls — we arrive knowing the generator's recent state and can focus on what's likely vs full diagnostic from scratch.

Realistic PSPS response timing: maintenance contract customers typically 2-4 hours response, non-contract customers typically 4-8 hours response during major events. The structural answer isn't to convert all customers to contracts (we have capacity limits); it's to prioritize ongoing maintenance investment over emergency response investment. Generators that exercise quarterly and get annual maintenance simply fail less often during PSPS — that's the highest-ROI investment for backup reliability.

Frequently Asked Questions

My generator won't start during a PSPS — what should I check?

Two quick checks before calling: 1) Look at the controls panel for any displayed fault codes or messages — many modern generators display a specific reason for failure. 2) Check the battery — most generators have a status LED indicating battery health. Don't try to bypass safety interlocks or force-start manually unless you know the equipment. Call us at 415-419-5960; we can often talk you through additional checks over the phone and dispatch if needed. PSPS demand extends response times — calling early in the event is better than calling late.

How much does an emergency generator repair cost?

Most emergency generator repairs run $400-$1,200 all-in including emergency response fee and parts. Battery replacement (most common emergency repair): $300-$600. Transfer switch component-level repair: $400-$900. Fuel supply correction: $300-$700 depending on cause. Engine-level diagnostic and repair varies widely with cause. Emergency premium runs 50-100% above scheduled rates, more for nights/weekends. Flat-rate quote at on-site assessment before work begins.

Why does my generator only fail when I need it?

Accumulated maintenance deficit. Generators that run weekly (in some applications) or even monthly with under-load exercise reveal issues progressively — battery degradation shows up before total failure, transfer switch actuator issues show up before total failure, fuel supply issues show up before they prevent operation. Generators that don't run between annual service appointments accumulate all of these issues invisibly, and the moment of need reveals everything at once. Quarterly under-load exercise is the highest-ROI preventive measure for backup reliability.

Can I get on a maintenance contract after an emergency repair?

Yes — we typically discuss maintenance contract enrollment as part of emergency response wrap-up. The post-emergency conversation is a good time because the value of preventive maintenance is concrete (you just experienced the alternative). Maintenance contract enrollment doesn't require waiting for renewal periods; we can start coverage within days of the emergency repair. Cost varies $480-$1,800/year depending on generator size and contract scope; PSPS priority response is included.

What if my transfer switch is the problem?

Transfer switch issues typically split into: controls/sensing failure (the ATS didn't recognize the outage and signal the generator), mechanical actuator failure (the ATS recognized the outage but didn't physically move to generator), or contactor failure (the ATS attempted to transfer but couldn't make/break properly). Each has different diagnostic and repair paths. Most ATS issues are remediable with component-level repair — controls modules, actuators, contactors — rather than full ATS replacement. Full ATS replacement runs $2,400-$5,800 if required; component repair runs $400-$1,200.

Should I run my generator in manual bypass while waiting for repair?

Generally no, unless we've specifically walked you through the safe procedure for your equipment. Manual bypass operation requires understanding the specific ATS design and the generator's controls — incorrect bypass can back-feed the utility lines (deadly for utility crews working on restoration), damage the ATS, or damage the generator. Wait for our dispatch; we'll either restore automatic operation or set up safe manual operation with proper isolation. The temporary inconvenience is worth the safety margin.

How We Reviewed This Page

Reviewed against current California Electrical Code (Title 24, Part 3) and 2023 NFPA 70 (NEC) provisions applicable to the topic.
Pricing ranges reflect actual 2026 Towery Electric quote data from Marin County jobs — not third-party industry averages.
Permit and inspection timing reflects current AHJ practice in Novato, San Rafael, Mill Valley, and unincorporated Marin County as of mid-2026.
Technical review by Alex Towery, founder and C-10 #989290 holder, with 11+ years of California electrical work.
All factual claims about code requirements were verified against primary sources (CSLB, CARB, PG&E, AHJ) at time of publication.

References

This guide reflects Towery Electric's professional standards as a California-licensed C-10 electrical contractor and is for general information. Site conditions, panel configurations, code amendments, and permit-authority requirements vary; final scoping, sizing, and code compliance for your specific address are determined on a paid site assessment. We follow California Electrical Code (Title 24, Part 3) and applicable NFPA 70 (NEC) editions adopted by your AHJ.