When your oil furnace starts making strange rumbling, banging, or sputtering noises in the middle of a Lower Bucks County winter, it’s trying to tell you something important—you’re likely running low on heating oil. These warning sounds aren’t just annoying; they’re your heating system’s way of signaling that fuel levels are dropping and action is needed before you lose heat entirely. Ace Fueling, a Bristol-based heating oil delivery company serving more than 5,000 customers since 2018, offers same-day delivery with no contracts and transparent pricing that saves families $300–$600 per heating season—but the best time to call is before your tank runs dry.
Many Bristol, Levittown, and Bensalem homeowners have experienced that moment of panic when their furnace starts acting up on the coldest night of the year. You’ve probably tried turning the thermostat up or pressing the reset button—but the noises keep coming back. That’s because the root cause isn’t mechanical failure. It’s your oil tank telling you it’s time to refuel.
In this guide, we’ll walk you through the five warning signs that your furnace is running low on oil, explain what’s actually happening inside your system, and show you how to avoid the costly consequences of letting your tank run dry. Whether you’re in Fairless Hills, Croydon, or anywhere across Bucks County, this information could save you from a freezing night and an expensive repair bill.
What You’ll Learn
- What Happens When Your Oil Tank Gets Low?
- The Real Causes Behind Low-Oil Furnace Problems
- 5 Warning Signs You’re Running Low on Oil
- What to Do When You Notice These Warning Signs
- Why Lower Bucks County Homeowners Choose Ace Fueling
- Frequently Asked Questions
- Next Steps
What Happens When Your Oil Tank Gets Low?
When the oil level in your tank drops below the quarter-full mark—roughly 69 gallons in a standard 275-gallon tank—your furnace begins operating in conditions it wasn’t designed for. Instead of drawing clean, consistent fuel from the middle of the tank, the system starts pulling from the bottom where sediment, water, and sludge have settled over time. The nozzle starts receiving contaminated fuel, the oil filter clogs faster, and air begins finding its way into the fuel lines.
Lower Bucks County homeowners are especially vulnerable during January and February, when Pennsylvania temperatures regularly dip into the 20s and 30s. At these temperatures, a typical 2,000-square-foot home burns through 5 to 7 gallons of heating oil per day. That means a quarter-tank can disappear in as little as 10 to 14 days—faster than many homeowners realize.
The Real Causes Behind Low-Oil Furnace Problems
Understanding why your furnace acts up when oil gets low helps you diagnose the problem accurately and avoid unnecessary repair calls. In our 7 years serving Lower Bucks County homeowners, these are the four root causes we see most often.
Air Infiltration in Fuel Lines
When your oil tank drops to low levels, the fuel pickup tube can begin pulling in air along with fuel. Air in the fuel line disrupts the steady flow of oil to the burner nozzle, causing the flame to sputter, stall, or fail to ignite altogether. This is the most common cause of the gurgling and sputtering sounds that Bucks County homeowners hear when oil levels are low.
Sediment and Sludge Contamination
Every oil tank accumulates sediment over time. Rust particles, dirt, and degraded fuel byproducts gradually settle to the bottom, forming a layer of sludge. When the tank is full, the fuel pickup draws clean oil from well above this layer. But as oil levels drop, the intake gets closer to the sludge zone, and contaminated fuel enters the system. This sediment clogs your oil filter and burner nozzle, causing the inconsistent combustion that produces rumbling and banging noises.
Condensation and Water in the Tank
A partially empty tank has more interior surface area exposed to air, which creates condensation—especially in Bristol, Croydon, and Morrisville homes with outdoor above-ground tanks during Pennsylvania’s cold winters. Water is heavier than oil and sinks to the bottom, where it can freeze in extremely cold weather and block the fuel line. Water that doesn’t freeze promotes bacterial growth that breaks down fuel quality and creates additional sludge.
Increased System Strain and Wear
Running a furnace on low oil forces the entire system to work harder. The oil pump strains to draw fuel, the motor runs longer cycles, and the burner endures repeated failed ignition attempts. Based on our deliveries to 5,000+ customers, we’ve found that this accelerated wear is especially concerning for Levittown and Bensalem homeowners with older furnaces—where additional strain can be the difference between a system that lasts another decade and one that requires emergency replacement mid-winter.
5 Warning Signs You’re Running Low on Oil
Now that you understand what’s happening inside your system, here are the five warning signs to watch and listen for.
1. Rumbling, Banging, or Gurgling Noises
A low rumble when your furnace kicks on is normal. But loud, prolonged rumbling, banging, or gurgling sounds point to trouble. These noises typically indicate air in the fuel line or sediment reaching the burner. If you hear a series of bangs when the furnace starts—or a gurgling sound coming from near the oil tank or fuel lines—your oil level is likely critically low. This is the most common warning sign we hear about from homeowners across Lower Bucks County.
2. Sputtering at Startup or Needing Repeated Resets
If your furnace struggles to fire up and you find yourself pressing the red reset button on the burner motor more than once, low oil is a likely culprit. When air enters the fuel line from a nearly empty tank, the burner can’t establish a consistent flame and triggers the safety shutdown. Pressing the reset button once is fine—but if you’re doing it daily, your system is running on fumes. Do not press the reset button more than two or three times. This can flood the combustion chamber with unburned oil and create a dangerous puffback situation.
3. Cold or Lukewarm Air Blowing from Vents
When the burner can’t ignite properly due to insufficient fuel, the blower fan continues to run—but it circulates unheated air. If you notice the air from your vents isn’t as warm as it should be, or if heat comes and goes inconsistently, your furnace may be struggling with fuel starvation. This is especially noticeable in Langhorne and Morrisville homes during January cold snaps when you expect steady, reliable warmth.
4. Frequent Short Cycling
Short cycling means your furnace turns on, runs briefly, shuts off, and then restarts shortly after—repeating this pattern continuously. While short cycling can have several causes, in oil furnaces it frequently points to low fuel levels. The burner ignites, runs until the inconsistent fuel supply causes a flame failure, shuts down on safety, and then tries again. You’ll notice your home never quite reaches the set temperature.
5. Complete System Shutdown
The final warning sign isn’t a noise at all—it’s silence. When your oil tank is empty, the furnace’s built-in safety mechanism shuts the system down entirely to prevent damage. At this point, simply adding oil may not be enough. Air in the fuel lines needs to be bled out, and the oil filter likely needs replacement before the furnace can restart. For Feasterville-Trevose and Southampton homeowners, this often means an expensive emergency service call on top of the fuel delivery.
What to Do When You Notice These Warning Signs
Check Your Tank Gauge First
Before assuming something is mechanically wrong, check your oil tank gauge. Most standard 275-gallon tanks have a float-style gauge on top. If the red disc shows a quarter tank or below, fuel level is almost certainly the issue. To confirm it’s working, unscrew the plastic vial and gently press the disc—if it slowly rises back up, there’s oil in the tank, but order soon.
Order Oil Immediately
When you spot any of these warning signs, don’t wait. Heating oil delivery from Ace Fueling can often arrive the same day for Lower Bucks County homeowners. Orders placed before 2 PM are typically delivered that same day. Call (215) 458-7523 or text Jon directly at (267) 679-2242 for fast response—often within minutes.
Don’t Keep Pressing the Reset Button
Pressing the reset button more than two or three times can flood the combustion chamber with unburned oil, creating a serious safety hazard called a puffback—a small explosion that blows soot and debris throughout your home. If two resets don’t get the furnace running, stop and call for professional help.
Use Diesel as a Temporary Fix
If you’ve run completely dry and can’t wait for delivery, you can add 5 to 10 gallons of diesel fuel from a gas station to your oil tank as a temporary measure. Diesel is compatible with heating oil and can get your system running until your delivery arrives. After adding diesel, wait about 10 minutes for any impurities to settle before attempting to restart the system.
Prevent It from Happening Again
The best solution is to never let your tank drop below a quarter full. At Ace Fueling, we make this easy with our no-contract, COD delivery model—order exactly when you need it, at current market rates, with same-day service 7 days a week. No locked-in contracts, no automatic deliveries, no surprises. Many of our 5,000+ customers in Bristol, Levittown, and Bensalem have found that proactive ordering saves hundreds of dollars per year in avoided emergency calls and repairs.
Why Lower Bucks County Homeowners Choose Ace Fueling
Since 2018, Ace Fueling has been the trusted heating oil delivery choice for families throughout Lower Bucks County. Owner Jon built this business on a straightforward promise: transparent pricing, reliable service, and treating every customer like a neighbor.
When your furnace starts making warning noises on a freezing January night, the last thing you need is an automated phone system or a three-day delivery wait. That’s why Jon answers calls and texts directly—no overseas call centers, no scripted responses. When a Levittown family ran out of oil on the coldest night of the month, Jon took the call at 6 PM, had oil in their tank by 8 PM, and bled the lines and restarted the system so they didn’t need a separate service call.
What sets Ace Fueling apart:
- Lowest Prices Guaranteed — Price match guarantee saves families $300–$600 per heating season
- Same-Day Delivery, 7 Days a Week — Orders before 2 PM typically delivered same day
- No Contracts, Ever — COD model with complete transparency and no hidden fees
- 24/7 Emergency Service — Typical response within 2–4 hours, even nights and holidays
- Licensed, Insured, DOT-Registered (#3148867) — Calibrated metering systems certified for accuracy
- 5,000+ Satisfied Customers — 5-star average Google rating
- Text Message Ordering — Text Jon at (267) 679-2242 for quick response
- Multiple Discounts — Military/Veterans 3¢/gal, Seniors 3¢/gal, Cash 5¢/gal, Referrals $25 off
Based in Bristol and serving homeowners from Warminster to Fairless Hills and everywhere in between, Ace Fueling understands the unique heating challenges Lower Bucks County families face—from the area’s older housing stock to the demand spikes during Pennsylvania’s harshest cold snaps.
Frequently Asked Questions
What does it mean when my furnace makes a rumbling or banging noise?
Rumbling or banging noises in an oil furnace typically indicate air in the fuel line or sediment reaching the burner—both common signs that your oil tank is running low. When the fuel level drops, air can enter the line and cause the burner to sputter, while sediment from the tank’s bottom can clog the nozzle and filter. Check your tank gauge and order oil promptly. Call Ace Fueling at (215) 458-7523 for same-day delivery.
How do I know when to order more heating oil?
Order more heating oil when your tank gauge shows a quarter full or less—roughly 69 gallons in a standard 275-gallon tank. During the coldest Pennsylvania winter months, a typical home burns 5 to 7 gallons per day, so a quarter tank can last just 10 to 14 days. Ordering early prevents emergency situations and furnace damage.
Can running out of heating oil damage my furnace?
Running out once won’t permanently damage your furnace, as it has a built-in safety shutdown. However, it can cause air to enter fuel lines (requiring professional bleeding), clog your oil filter with sediment, and lead to condensation and rust in the tank. Repeated run-outs accelerate wear on the oil pump and burner, shortening your system’s lifespan.
What should I do if my furnace stops working during a cold night?
Check your oil tank gauge. If it reads empty or very low, contact Ace Fueling at (215) 458-7523 for 24/7 emergency delivery—we typically respond within 2 to 4 hours. As a temporary measure, add 5 to 10 gallons of diesel fuel to your tank, wait 10 minutes, and try pressing the reset button once.
How much does heating oil delivery cost in Lower Bucks County?
Ace Fueling offers competitive heating oil prices with a price match guarantee, saving families $300 to $600 per heating season compared to contract companies. Call (215) 458-7523 or text (267) 679-2242 for today’s current pricing. Additional discounts are available for military/veterans (3¢/gal), seniors (3¢/gal), and cash payments (5¢/gal).
Can I get same-day heating oil delivery in Bristol, Levittown, or Bensalem?
Yes. Ace Fueling offers same-day heating oil delivery throughout Lower Bucks County, 7 days a week, including weekends and holidays. Orders placed before 2 PM are typically delivered the same day. Call (215) 458-7523 or text (267) 679-2242 to schedule.
Does Ace Fueling require contracts or minimum orders?
No. Ace Fueling operates on a COD (cash on delivery) model with no contracts, no long-term commitments, no automatic deliveries, and no cancellation fees. You order only when you need oil, at current market rates, with flexible ordering quantities.
Is it safe to put diesel fuel in my heating oil tank in an emergency?
Yes, diesel fuel (specifically ultra-low sulfur diesel) is compatible with heating oil and works as a temporary substitute. Add 5 to 10 gallons, wait about 10 minutes for sediment to settle, then restart your furnace. Contact Ace Fueling for a full heating oil delivery as soon as possible.
Next Steps
If your furnace is making strange noises or showing any of the warning signs described above, here’s what to do right now: check your oil tank gauge, and if it reads a quarter full or below, order heating oil today.
Key takeaways:
- Strange furnace noises usually mean your oil is running low—not that something is mechanically broken
- Never let your tank drop below the quarter mark (about 69 gallons in a 275-gallon tank)
- Don’t press the reset button more than twice—call for help instead
- Proactive ordering prevents emergency situations and costly furnace repairs
Ready for reliable, affordable heating oil delivery?
Call: (215) 458-7523
Text: (267) 679-2242
Online: ace4oil.com
Jon answers directly—not an automated system. Same-day delivery available 7 days a week, with 24/7 emergency service. No contracts, no hassle—just honest pricing and reliable delivery.
Military/Veterans: 3¢ off/gal | Seniors: 3¢ off/gal | Cash: 5¢ off/gal | Referrals: $25 off for both you and your friend
Your House Always Wins!
