A fuel oil tank inspection in Wallonia checks a heating oil tank for leaks and compliance and results in a coloured plate: green means it may be filled, orange means fix within six months, red means no filling. Tanks from 3,000 to 25,000 litres are fully regulated (fueltankcontrol.be, 2026).
If a Walloon home is heated with fuel oil (mazout), the storage tank is subject to environmental rules designed to prevent soil and groundwater pollution. An approved technician inspects the tank, its piping and its anti-overflow and gauge equipment, then affixes a coloured plate that tells you, at a glance, whether the tank can legally be filled.
Capacity sets the regime. Tanks between 3,000 and 25,000 litres fall under full regulatory obligations, while for tanks below 3,000 litres inspection is strongly recommended rather than strictly imposed (fueltankcontrol.be, 2026). Since the rules of 13 May 2020, tanks of 500 litres or more must have double protection or a suitable equivalent, an automatic anti-overflow device, a compliant gauge and a sealed plate on the fill pipe (fueltankcontrol.be, 2026).
The colour code is the heart of the system. A green plate allows filling and is valid for 3 years for a single-wall tank or 10 years for a double-protection tank. An orange plate permits filling for only 6 months, the window to correct a defect. A red plate forbids filling until the leak or fault is repaired and the tank is re-inspected (fueltankcontrol.be, 2026).
The counter-intuitive detail sellers miss: a buried or hard-to-reach tank often needs a tightness test, not just a visual check, which takes planning. Sorting the plate before listing avoids a last-minute scramble at the notary.
At a glance
| Item | Detail (source, date) |
|---|---|
| Purpose | Prevent oil leaks into soil and groundwater |
| Fully regulated capacity | 3,000 to 25,000 litres (fueltankcontrol.be, 2026) |
| Equipment rule since 13 May 2020 | Tanks 500 L and over need double protection, anti-overflow, compliant gauge |
| Green plate | May be filled, valid 3 or 10 years by tank type |
| Orange plate | Filling allowed 6 months, defect to be fixed |
| Red plate | No filling until repair and re-inspection |
| Frequency | Single-wall every 3 years, double every 10 years |