05 — Refresh
Fuel refresh: polishing and fuel replacement
Polishing can remove water and particles, but it can’t reverse fuel breakdown. Once diesel or HVO starts to oxidise, the damage is chemical. Filtering it buys you weeks, not years. So we test your fuel properly and, if it’s past its best, we replace it with fresh fuel that meets specification. Your generator then starts on fuel you can trust.
Key facts
| Tested for | Oxidation stability, acid number, water, microbial growth, ISO 4406 |
|---|---|
| Outcome | Lab-led decision on whether to treat or renew |
| Renewal includes | Removal, camera inspection, cleaning if needed, refill, verification |
| Evidence | Before and after lab certificates and waste transfer notes |
| Why renew | It’s a one-off cost instead of paying for polishing again every year, and it removes the risk of a failed start. |
How it works
- Test. We sample and send it to an ISO/IEC 17025 accredited lab. The lab checks oxidation stability, acid number, water, microbial growth and the ISO 4406 particle rating.
- Decide. If the fuel is chemically sound, we just remove the water and dirt. If it’s breaking down, we recommend renewal, with the lab evidence to show why.
- Renew. We remove the old fuel under Duty of Care. While the tank is empty, we inspect it with our ELOK camera and clean it if needed. Then we refill with fresh diesel or HVO.
- Verify. A lab certificate on the new fuel confirms it meets specification before we hand over.
What you receive
- Before and after laboratory certificates
- ISO 4406 cleanliness rating, before and after
- Water content and microbial results
- ELOK camera footage of the empty tank when fuel is renewed
- Waste transfer notes for removed water, residue and fuel
- Recommended retest date
Common questions
Why don’t you just polish the fuel?
Polishing filters out what’s floating in the fuel. It doesn’t fix fuel that’s chemically degrading. Oxidation products are dissolved in the fuel, so they pass through the filters and form sludge again once the fuel settles. You might get a better result on the day, but it won’t last. Renewing the fuel gives you a known starting point, a clean tank and a lab certificate to prove it.
Isn’t renewal more expensive than polishing?
On the day, yes. But polishing degraded fuel doesn’t last, so you end up paying for it again next year, and the year after that. Meanwhile the risk is still sitting in your tank. The real comparison is the cost of a generator that won’t start when the mains fails: lost uptime, damaged equipment, emergency call-outs, and on critical sites, service penalties or patient safety. Renewal gives you fuel that meets specification, a clean tank and a lab certificate proving both. That’s a one-off cost compared with a recurring cost and an open-ended risk.
Get a quote for fuel refresh
Renewal costs more than polishing on the day, but far less than a generator that fails to start when you need it.