A 20 lb propane tank holds 4.7 gallons. With a furnace running 6 hours/day, water heater 2 hours/day, and stove 1 hour/day, it lasts about 2–3 days. Without heating, using only the stove and water heater, it can last 7–10 days.
- 20 lb tank = 4.7 gallons = 429,450 BTU total capacity
- Heavy use (furnace + all appliances): 2–3 days per tank
- Moderate use (water heater + stove only): 7–10 days per tank
- Light use (stove only, 1 hour/day): 50+ days per tank
- Most RVs carry two 20 lb or 30 lb tanks for redundancy
| Usage Level | BTU/Day | Days per 20 lb Tank |
|---|---|---|
| Heavy (furnace + all) | ~175,000 | 2–3 |
| Moderate (heater + stove) | ~31,000 | 7–10 |
| Light (stove only) | ~7,000 | 50+ |