Why your electric bill jumped in Lake Mary, Florida
A sudden jump usually means the system is working harder for the same result — dirty coils, duct leakage or aging equipment — but in Lake Mary’s pool-heavy housing stock, a correctly running system can also simply be doing more work than the square footage suggests.
What is most likely wrong
- Dirty condenser or evaporator coil cutting efficiency Very common
The system works harder and longer to move the same heat; often paired with weak cooling.
- Duct leakage into a hot attic Common
Conditioned air paid for never reaches a register — especially in 1988–1996 attic duct systems.
- Aging, pre-SEER2 equipment nearing end of life Common
Efficiency degrades with age even without an obvious fault.
- Long runtime from a pool-heavy cooling and dehumidification load Common in Lake Mary
Not a fault at all — a correctly running system in a pool house uses more electricity than the same tonnage in a house without one.
- Refrigerant undercharge forcing longer cycles Less common
The system runs longer to reach the same setpoint, using more electricity for the same result.
What you can safely check yourself
- The filter and condenser coil — the two easiest efficiency thieves to fix yourself.
- Whether the increase lines up with a change in weather, occupancy, or the pool pump or heater schedule rather than the AC itself.
- The thermostat’s runtime or cycle history, if it has one — a steady increase in daily runtime points at efficiency loss rather than a single fault.
- The age on the outdoor unit’s data plate — equipment older than about 12–15 years is a different conversation than a $150 repair.
Refrigerant, capacitors and the inside of an electrical panel are not homeowner jobs — a run capacitor holds a lethal charge after the disconnect is pulled, and refrigerant handling requires EPA Section 608 certification under 40 CFR Part 82 subpart F.
In Florida, an air-conditioning contractor licensed under Chapter 489 may replace, disconnect and reconnect the power wiring at the dedicated disconnect — s. 489.105(3) — which is exactly why that scope exists: it is not general household electrical work. Verify any Florida air-conditioning contractor’s licence at myfloridalicense.com.
Why this shows up in Lake Mary and Heathrow
44.5% of improved residential parcels in the City of Lake Mary tax district have a pool, the highest share of the seven Seminole County cities measured, and a pool house carries a real latent-load cost that shows up on the bill even when nothing is broken. Before assuming a fault, rule out the two that inflate a bill fastest: a dirty condenser coil, and duct leakage into an attic that runs well over 120°F in summer. Seminole County Property Appraiser CAMA extract (parcel file dated 5 September 2026), tax district M1 — City of Lake Mary — improved residential parcels only.
If the bill jump coincides with a Duke Energy account, a free Home Energy Check is the fastest way to separate a real fault from ordinary Florida cooling load — and it is also the prerequisite for any Duke replacement rebate, so there is no downside to booking one early. Duke Energy rebates ›
What the fix typically costs
| Item | Researched range | What drives it |
|---|---|---|
| Duct sealing | $500–$2,500 | Orlando; individual section replacement runs $200–$800. |
| Maintenance tune-up | $79–$149 | Orlando contractor-published range for a single visit. |
Researched Central Florida ranges gathered 12 September 2026 for research/pricing.json: Orlando-metro contractor-published prices corroborated against a third-party Orlando cost guide, with any aggregator figure labelled as such. These are market ranges, not our prices, and not a quote.
Sources for this page
- Smart Home Air & Heat — new AC unit cost Orlando
- Smart Home Air & Heat — HVAC maintenance Orlando
- Seminole County Property Appraiser
Researched 6 September 2026. Fees, rebate amounts and code minimums change — check the issuing authority before you rely on a figure.