How to Replace and Site a New Heating Oil Tank

Thinking about replacing your heating oil tank? Whether you’re retiring an aging tank or installing a new one, getting the siting and installation right matters for safety, compliance, and long-term reliability. This guide walks you through when to replace, how to choose capacity and construction, what the base and location must look like, and who should do the work.

When Should You Replace Your Oil Tank?

Most tanks last around 15–20 years, depending on material, exposure, and maintenance. Plan a replacement if you notice:

  • Cracks, bulging, rust, or UV degradation
  • Persistent oil odours, damp patches, or staining near the base
  • Unexplained drops in fuel level
  • An older single-skin tank (often non-compliant in many UK settings)

Annual checks by an OFTEC-registered technician help you spot issues early. For legal responsibilities and siting rules, see the UK guidance on storing oil at a home or business.

Choosing the Right Type and Capacity

Two common domestic options:

  • Plastic bunded tanks – light, corrosion-resistant, integral secondary containment; ideal for most homes.
  • Steel tanks – robust but need anti-corrosion care; often used for commercial/agricultural sites.

Capacity typically ranges 1,000–2,500 L for UK homes. Think about your annual usage, refill frequency, and space. If you’re comparing models, browse real-world sizes and footprints in our Bunded Oil Tank collection.

Want a plain-English explainer of how bunded tanks work and why they’re safer? See How Bunded Oil Tanks Work: Essential Guide.

Siting and the Base: What’s Required

Correct siting is non-negotiable for safety and compliance:

  • Base: firm, level, non-combustible, and extending at least 300 mm beyond all sides of the tank. Concrete slab or solid paving is typical.
  • Clearances: observe separation from buildings, boundaries, heat sources, and flues (check local Building Regulations and OFTEC guidance for exact distances).
  • Access: allow room for deliveries, inspection, and maintenance; keep vegetation back and drainage clear.

OFTEC’s consumer guide summarises domestic requirements and good practice for tanks up to 3,500 L: Home Guide to Domestic Liquid Fuel Storage.

Who Should Install Your Tank?

Use a competent person (OFTEC-registered) for replacement or new installs. A typical job includes:

  1. Safely decommissioning and draining the old tank (if applicable)
  2. Verifying or constructing a compliant base
  3. Installing the new tank, pipework, isolation valves, and filter
  4. Fitting overfill prevention and correct venting
  5. Commissioning, leak-testing, and providing documentation

DIY installs risk non-compliance, leaks, and insurance issues—don’t do it.

FAQs

How long do tanks last?
Plastic bunded tanks ~15–20 years with proper siting and maintenance; steel can be shorter without protection.

Do I need planning permission?
Usually not for domestic tanks under 3,500 L, unless your property is listed or in a conservation area. Always check your local authority.

Can I reuse my existing base?
Only if it’s level, non-combustible, and extends 300 mm beyond the tank on all sides. Otherwise, rebuild it.

Is self-installation legal?
You need a competent installer. Self-installing can breach Building Regulations and void warranties/insurance.

How do I maintain my tank?
Monthly visual checks for damage and leaks; annual service by an OFTEC technician; keep the base clear and stable.

Ready to Replace Your Tank?

Posted on 19 September 2025 in Uncategorized