Diesel Tank Ran Dry Without Warning? Set These 3 Alerts

Short answer

A diesel tank needs three alerts. Low, when the level falls below 35% of capacity, goes to the person who orders fuel. Critical, below 20%, reaches the site manager by SMS or WhatsApp. An unexplained drop, a fall in litres with no logged use, goes to security. Each needs a threshold, a recipient and a clear next action.

Key takeaways

Set three diesel tank alerts with different jobs: Low starts a refill, Critical protects the site, and an unexplained drop starts a check.
In ENTEK Fuel Tank a tank is Low below 35% and Critical below 20% of capacity, and a minimum you set for a tank takes priority over that default.
ENTEK checks alert rules every 30 seconds and delivers messages by email, SMS or WhatsApp, usually within about a minute.
A slow fall overnight can be temperature, not theft: diesel at 40 °C takes about 0.9% more space than at 30 °C, so judge drops over short windows.
An unexplained drop is a reason to check the site, not proof of a cause. Compare it with refuel events, generator hours and delivery notes first.

01Why one low-level alarm is not enough

Many sites run a diesel tank with a single alarm: a light or a message when the level gets low. The problem is that one alarm tries to do three different jobs. It has to tell the buyer to order fuel, tell the site manager that a generator or machine may stop, and tell someone when fuel disappears for no clear reason. These jobs need different people, different urgency and different actions. If they share one message, the buyer ignores it because it comes too often, the manager hears about a shortage too late, and a sudden loss of 300 litres at night looks like normal use. So split the alarm into three recipes. Each recipe in this article is a card with five parts: the trigger, the threshold, who gets it, the channel, and what the person should do next. Write the cards down before you configure anything, then set the platform to match them, not the other way round.

02Recipe 1: Low, the refill reminder

The Low alert exists to buy time. In ENTEK Fuel Tank a tank counts as Low when it falls below 35% of capacity, and you can also set your own minimum for each tank in Tanks Control. When you set one, that minimum wins over the percentage, which matters for a tank that serves a large generator and needs ordering earlier. A good Low threshold leaves enough fuel to cover your supplier’s normal delivery time plus one spare day of use. Send it by email to the person who orders fuel, and copy the site supervisor. It is a planning message, so it does not need SMS at 3 a.m. The action is simple: check the level history, confirm the order quantity, and raise the order. ENTEK does not order fuel by itself. A person drafts and approves the request, for example through an RFQ to verified suppliers on the ENTEK marketplace at entek.ai.

03Recipe 2: Critical, protect the site

Critical means the next step is a stopped generator, a stopped machine or a dry fuel station. In ENTEK Fuel Tank a tank is Critical below 20% of capacity. This alert should reach a person who can act tonight, so send it by SMS and WhatsApp to the site manager and to the person on duty, with email as the record. Set a high severity and a short hold time, so a single bad reading does not wake people, but a real low level does. Be honest about timing: ENTEK checks rules every 30 seconds and messages usually arrive within about a minute, plus any hold time you add. The action list for Critical is different from Low. Confirm the level on site, call the supplier to bring the delivery forward, and if needed reduce load on the generator or move fuel from another tank. When the delivery arrives, the platform records a Refuel event with the litres before and after.

04Recipe 3: the unexplained drop

The third recipe watches for fuel that leaves the tank faster than your normal use. ENTEK Fuel Tank records Fuel Drop events and can alert on a sudden drop. Call it an unexplained drop: the platform sees litres go down, it does not know why. Set the size of drop that matters with ENTEK during setup, well above the normal use of your heaviest hour, so a running generator does not trigger it. Send it by WhatsApp and SMS to security and to the operations lead. The action is to check before you accuse: was a generator running, was fuel moved to another tank, did a sensor lose signal? Smoothing matters here. A noisy probe can show small jumps that look like drops, so the reading must be steady before a drop rule is useful, which is the point of our article on input smoothing. Temperature matters too: a slow fall over a night is often the fuel cooling, not fuel leaving.

05A worked example in SAR for a 20,000 litre tank

Take a 20,000 litre diesel tank feeding a site generator in Riyadh. With the default ladder, Low starts below 7,000 litres (35%) and Critical below 4,000 litres (20%). If your supplier needs two days and the site uses about 1,500 litres a day, 7,000 litres covers more than four days, so the default works; a site using 3,000 litres a day should set its own minimum higher. Now the drop. Aramco lists diesel at SAR 1.79 per litre for October 2026, so an unexplained drop of 300 litres is worth about SAR 537, and three such nights a month are about SAR 1,611. Compare that with temperature. Measurement Canada’s diesel tables give a correction factor of 0.9873 at 30 °C and 0.9788 at 40 °C, so the same fuel takes about 0.9% more space when hot. With 12,000 litres in the tank, a 10 °C cool-down shows roughly 104 litres less, spread over hours, not minutes.

06Who gets what, and how to keep alerts trusted

An alert is only useful if people still read it after a month. In ENTEK each device has its own recipients for email, SMS and WhatsApp, and you can add company-wide recipients, so match the list to the recipe card rather than sending everything to everyone. Use the built-in rule types: a minimum value for Low and Critical, and a no-signal rule for a probe that stops reporting, because a silent tank tells you nothing about theft or shortage. Add a hold time where noise is common, and a cooldown so one event does not send ten messages; our articles on debounce timers and hysteresis explain both ideas. Review the cards every quarter with the Alerts page, where each alert can be acknowledged, and the delivery counters, which show how many messages were sent and how many failed per channel. If a recipe fires often and nobody acts, change the threshold or the recipient, not the habit of ignoring it.

Diesel tank alert recipe cards
Recipe	Trigger	Threshold	Who gets it	Channel	What to do
Low	Level falls below the Low line	Below 35% of capacity, or your own minimum per tank (it wins)	Fuel buyer, copy to site supervisor	Email	Check level history, confirm quantity, draft and approve the fuel order or RFQ
Critical	Level falls below the Critical line	Below 20% of capacity; high severity, short hold time	Site manager and person on duty	SMS and WhatsApp, email as record	Confirm on site, bring delivery forward, reduce generator load or move fuel
Unexplained drop	Fuel Drop event larger than normal use	Agreed with ENTEK at setup, above your heaviest hour of use	Security and operations lead	WhatsApp and SMS	Check generator hours, transfers and signal before any conclusion
Refuel recorded	Refuel event with litres before and after	Automatic, no threshold to set	Fuel buyer or accounts	Events page (a record, not a message)	Match the litres with the delivery note
No signal	Probe stops reporting	A set time with no data	Site supervisor	SMS or email	Check power, wiring and the tracker before trusting the level again

Worked example: 20,000 litre tank, diesel at SAR 1.79 per litre (Aramco, October 2026)
Item	Calculation	Result
Low line	20,000 L x 35%	7,000 L
Critical line	20,000 L x 20%	4,000 L
Days of cover at Low, 1,500 L per day	7,000 / 1,500	about 4.7 days
Value of one 300 L unexplained drop	300 x SAR 1.79	about SAR 537
Three such drops in a month	3 x SAR 537	about SAR 1,611
Apparent fall from a 10 °C cool-down, 12,000 L in tank	12,000 x (0.9873 / 0.9788 - 1)	about 104 L, over hours

Figures and sources

Saudi retail diesel price per litre, October 2026: SAR 1.79 per litre (Source: Aramco, retail fuels prices for the month of October 2026, as of 2026-10-19)
Volume correction factor to 15 °C for diesel at 30 °C: 0.9873 (Source: Measurement Canada (ISED), volume correction factors for diesel, bio-diesel and diesel blends, as of 2026-10-19)
Volume correction factor to 15 °C for diesel at 35 °C: 0.9830 (Source: Measurement Canada (ISED), volume correction factors for diesel, bio-diesel and diesel blends, as of 2026-10-19)
Volume correction factor to 15 °C for diesel at 40 °C: 0.9788 (Source: Measurement Canada (ISED), volume correction factors for diesel, bio-diesel and diesel blends, as of 2026-10-19)
Reference diesel density used for the correction table: 840 kg/m3 at 15 °C (table 54B) (Source: Measurement Canada (ISED), volume correction factors for diesel, bio-diesel and diesel blends, as of 2026-10-19)

Questions

At what level should a diesel tank send a low fuel alert?

ENTEK Fuel Tank marks a tank Low below 35% of capacity and Critical below 20%. If your supplier is slow or your use is high, set your own minimum for that tank; it takes priority over the percentage. Aim for enough fuel to cover delivery time plus one spare day.

How fast will I get the alert?

ENTEK checks alert rules every 30 seconds and sends messages by email, SMS or WhatsApp, usually within about a minute. Any hold time you set to filter noise adds to that.

Does a sudden drop alert mean someone is stealing diesel?

Not by itself. The platform sees litres go down; it does not know why. Treat it as an unexplained drop and check generator hours, fuel transfers, sensor signal and temperature before you decide what happened.

Why does my tank show less diesel in the morning when nobody used it?

Diesel shrinks as it cools. Measurement Canada’s tables give a factor of 0.9873 at 30 °C and 0.9788 at 40 °C, about 0.9% difference. On 12,000 litres a 10 °C cool-down shows roughly 104 litres less, spread over hours.

Will ENTEK order diesel automatically when the tank is low?

No. The alert tells the right person, and that person drafts and approves the order, for example as an RFQ to verified suppliers on the ENTEK marketplace at entek.ai.

Diesel Tank Ran Dry Without Warning? Low, Critical and Sudden Drop Alerts