If you rely on kerosene, also known as heating oil, to heat your home, knowing how to check your heating oil level is one of the simplest habits you can build into your routine. Whether you’re reading a float gauge, dipping the tank with a stick, or checking an app on your phone, a regular look at your tank tells you exactly when it’s time to reorder.
In this guide, we’ll walk through every method of checking your oil level, from the gauge fitted to most tanks to smart monitors that do the checking for you. We’ll also cover what to do if your gauge stops working, how much oil you should have left before you order more, and why rural households in particular shouldn’t leave it too late.
Why It’s Worth Checking Your Oil Level Regularly
Checking your heating oil level regularly means you never get caught out by a cold snap or a delayed delivery. It only takes a couple of minutes, and it gives you the lead time you need to order before the tank runs dry.
Unlike mains gas, heating oil is a delivered fuel. There’s no pipeline topping your tank up automatically, so it’s entirely down to you to keep track of what’s left. This matters more in rural Staffordshire, Cheshire, Shropshire and Derbyshire than it does in a town. Long farm tracks, single-track lanes and properties well off the main road can all add time to a delivery, particularly once winter demand picks up. If you wait until the tank is nearly empty before you order, you’re relying on everything going smoothly, and in bad weather, it often doesn’t.
Running out also isn’t just an inconvenience. An empty tank can let air into the fuel line, which may mean bleeding the system or calling out an engineer before your heating works again. It’s a problem that’s easy to avoid with a habit that costs you nothing.
How to Read a Float Gauge on Your Oil Tank
Most home heating oil tanks in the UK have a float gauge fitted to the top. It’s a simple, self-contained device with a clear plastic dome and a dial that moves as the oil level changes, and it’s the quickest way to get a rough idea of what’s in the tank.
Inside the gauge, a float sits on the surface of the oil and rises or falls with it. That float is connected to an arm, which moves a dial or disc visible through the dome. The dial is usually marked in quarters: Full, ¾, ½, ¼ and Empty. To check it, simply lift the lid on the gauge (if it has one) and read where the dial or disc is pointing.
A couple of things are worth knowing about float gauges:
- They’re approximate, not precise. The oil level can appear to drop faster or slower depending on your tank’s shape. Treat the reading as a guide, not an exact figure.
- They can stick over time. Sediment or a stiff hinge can cause the float to stop moving freely, giving you a false reading. If the dial hasn’t moved in weeks despite regular use, it may be stuck.
- “Empty” doesn’t mean completely empty. Most tanks retain a small amount of oil at the very bottom that the gauge can’t register, partly by design, to avoid drawing up sediment.
If your gauge seems to be stuck or reading inconsistently, a quick manual check with a dipstick will confirm whether it’s the gauge at fault or your fuel that’s genuinely low.
How to Check a Sight Gauge
A sight gauge is a clear tube fitted to the side or base of the tank that shows the oil level directly, using a simple pull-to-read or push-button valve. When operated, the valve lets a small amount of oil into the tube, and because of gravity, it settles at the same level as the oil inside the tank.
To read one, press or pull the button at the base of the tube, wait a moment for the oil to settle, then read the level against the markings on the tube itself.
It’s worth flagging a safety point here. OFTEC, the body that sets standards for oil heating equipment in the UK, advises against fitting bottom-outlet sight gauges to bunded oil tanks, because they create an extra weak point where oil could leak. New bunded tanks are no longer fitted with them for this reason, though older installations with a sight gauge already fitted are still common. Our guide to heating oil tank regulations covers this in more detail if you’re unsure what type of tank you have or whether your gauge is fitted safely.
How to Use a Dipstick to Check Oil Levels
A dipstick is the most reliable manual method for checking your heating oil level, particularly if your gauge is faulty, missing, or you simply want to double-check a reading. All you need is a clean, straight stick or purpose-made dipstick and a steady hand.
Here’s how to do it:
- Locate the fill or inspection cap on top of the tank and remove it carefully.
- Lower the stick straight down until it touches the bottom of the tank, taking care not to force it.
- Hold it in place for a few seconds, then lift it out slowly.
- Read the wet mark left on the stick. This tells you the depth of oil in inches or centimetres.
- Compare the measurement against a tank capacity chart for your specific tank size and shape to estimate how many litres remain.
A few safety points are worth keeping in mind. Always keep naked flames, cigarettes and anything that could spark well away from the tank whilst you do this. Wear gloves if you can, since heating oil can irritate skin with prolonged contact, and replace the cap securely once you’ve finished.
Electronic and Smart Oil Tank Monitors
Electronic monitors take the guesswork out of checking your heating oil level entirely, giving you a reading from inside your home rather than a trip out to the tank. They’re an increasingly common upgrade for households who want peace of mind without the regular walk outside, particularly useful if your tank is some distance from the house, which is common on larger rural plots.
There are two main types you’ll come across in the UK:
- Ultrasonic monitors. A small transmitter sits on top of the tank and measures the oil level using sound waves, then sends the reading wirelessly to a receiver plugged in inside your home. Most display the level in bars or tenths rather than an exact litre figure.
- Smart Wi-Fi monitors. These work in a similar way but connect to an app on your phone, giving you a more precise reading along with usage trends and, in some cases, an estimate of your run-out date.
Both types typically include a low-level alert, so you get a warning as your tank approaches empty rather than having to remember to check. They’re battery-powered, and batteries generally last several years before needing replacement. It’s important to note that these types of monitor must be calibrated before installation to ensure correct levels.
If you’re considering one, it’s worth checking that it’s compatible with your tank type, particularly if you have a bunded tank, and that it’s fitted correctly so the reading stays accurate over time.
Thinking of having a smart tank monitor installed? Chat to the Stoddards team today.
How Often Should You Check Your Heating Oil Level?
You don’t need to check your oil level every day, but a regular habit makes all the difference. As a general rule, check once a month outside the heating season and once a week during winter, when your usage is highest.
It’s also worth checking at a few specific points in the year:
- Just before the heating season starts, typically early autumn, so you know your starting position.
- After any spell of unusually cold weather, since a cold snap can burn through oil faster than normal.
- If your heating suddenly stops working, since running out of fuel is one of the most common causes.
- At the end of winter, so you’re not left with a near-empty tank heading into the summer months, when a lightly filled tank can be more prone to internal condensation.
When Should You Order More Heating Oil?
Order more heating oil once your tank drops to around a quarter full. This gives you a sensible buffer for delivery, particularly during winter when demand across the industry is at its highest and lead times can stretch. If you’re budgeting ahead, our guide to the cost of filling a heating oil tank can help you plan.
Ordering at a quarter full rather than waiting until the tank is nearly empty gives you room for the unexpected: a cold spell that pushes your usage up, a delivery that gets rescheduled due to weather, or simply a busier week than usual for your supplier. For households on longer rural routes, that buffer matters more, not less.
If keeping track feels like one more thing to remember, scheduled or automatic deliveries take the decision off your plate entirely. With our Diamond Service, Stoddards regularly monitor your heating oil level, and when it drops to an agreed level, we arrange a delivery for you, all taken care of by the Stoddards team.
What Happens If You Run Out of Heating Oil?
Running out of heating oil doesn’t just mean a cold house. It can let air into the fuel line, which usually needs bleeding before your boiler will fire again, sometimes requiring an engineer if you’re not confident doing it yourself. An empty or near-empty tank is also more prone to condensation forming inside it, particularly over summer, which over time can contribute to water contamination and internal corrosion.
If you do run out unexpectedly, our emergency oil delivery service is there to get you back up and running as quickly as possible.
Frequently Asked Questions
How do I check how much oil is in my tank?
The quickest way is to read the float gauge fitted to most tanks, which shows an approximate level as Full, ¾, ½, ¼ or Empty. For a more accurate figure, use a dipstick and compare the reading against a tank capacity chart, or fit an electronic monitor for a reading you can check from indoors.
How often should I check my heating oil level?
Check monthly during warmer months and weekly through winter, when usage is at its highest. It’s also worth checking after a cold snap or if your heating suddenly stops working.
At what level should I order more heating oil?
Order when your tank reaches around a quarter full. This gives you enough of a buffer to account for winter demand and any delays to delivery, especially if you’re in a more remote or rural location.
Why is my oil tank gauge not working?
A stuck or inaccurate gauge is usually down to a float that’s jammed with sediment or a hinge that’s stiffened over time. If the dial hasn’t moved despite regular use, check the level manually with a dipstick to confirm, and consider having the gauge inspected or replaced if it continues to give unreliable readings. It’s also worth checking the calibration of a smart or electronic monitor to be sure of it’s accuracy.
Keep Your Tank Topped Up With Stoddards
Whether you check your tank by eye, by dipstick, or with a smart monitor, the important thing is staying ahead of it, especially if you’re some distance from your nearest delivery route. Stoddards has been supplying heating oil to homes, farms and businesses across Staffordshire, Cheshire, Shropshire and Derbyshire for over almost 60 years, and we understand the demands of rural delivery better than most.
If you’d rather not think about checking the gauge at all, our scheduled and automatic delivery options keep your tank topped up automatically. And if you’re looking to upgrade to an electronic monitor, [link to oil tank monitor service page] can talk you through the options.
Get in touch with our team today to set up a delivery or ask any questions about your tank.