How auto-fill works
When you enrol in automatic delivery, the dealer builds a usage profile for your account based on a few inputs: your tank size, the appliances served, your home's square footage, and your historical consumption. Once enrolled, the dealer's routing system tracks heating degree days (HDDs) — a standard meteorological metric reflecting how cold each day has been — and forecasts when your tank will reach the trigger level for a refill.
The standard refill trigger is around 25-30% tank level. Hitting that level cues the next delivery to be scheduled within a few days. Your tank is filled to 80% (the standard maximum), giving you another 50-55% of capacity before the next refill.
Auto-fill vs will-call
The trade-off is straightforward — convenience and run-out protection vs flexibility:
| Aspect | Auto-fill | Will-call |
|---|---|---|
| Run-out risk | Minimal (dealer schedules) | High if you forget to call |
| Customer effort | None — set and forget | Monitor gauge, call dealer |
| Per-gallon rate | Usually slightly cheaper | Usually slightly higher |
| Suits | Heating customers, regular users | Light users, seasonal customers |
Most US residential propane heating customers default to auto-fill because the operational benefit — no run-out, no leak test fee, no missed-fill penalty — usually outweighs the modest flexibility loss.
What it costs
Auto-fill enrolment is typically free. The per-gallon rate is often slightly lower than the will-call rate (dealers value route-planning predictability and pass back some of the saving). The only material cost difference is that auto-fill customers can't time their fills to summer price lows — the dealer schedules from usage data, not market prices.
If you want both auto-fill protection AND price-low flexibility, the answer is to combine auto-fill with a pre-buy or capped contract at summer rates.
When auto-fill works and when it doesn't
Auto-fill works well for predictable usage patterns — full-time households with stable appliance loads and consistent climate. The dealer's forecast is most accurate when your year-to-year usage doesn't swing wildly.
It works less well when usage is hard to predict: vacation homes used intermittently, seasonal businesses, properties undergoing renovation that changes the appliance load, or homes that added a propane generator without telling the dealer. In these cases the dealer either over-delivers (you build inventory you don't need) or under-delivers (you risk run-out). Talk to your dealer when usage patterns change.
Frequently asked questions
Does auto-fill cost extra?
No — enrolment is typically free, and the per-gallon rate is usually slightly lower than the will-call rate. The dealer benefits from predictable routing; the customer benefits from no run-out risk.
Can I still control when deliveries happen?
Partially. You can request a fill at any time (priority fill, often with a small surcharge), and you can ask the dealer to skip a scheduled fill if your usage is low. But the routine schedule is the dealer's responsibility.
Do I still need to monitor my tank gauge?
Lightly. Check the gauge once a month during heating season — auto-fill forecasts are generally reliable but not infallible. If you see the level approaching 20% with no scheduled delivery, call the dealer.
What if auto-fill fails and I run out?
If the run-out is the dealer's fault under the auto-fill agreement, most dealers waive the standard leak-test and restart fee. Confirm this in writing when you enrol — it's a useful protection.