Oil heating explained

HVO & the Renewable Heat Obligation

You may have seen talk of “renewable heating oil” and a new rule coming for heating fuels. Here's the honest, plain-English state of play for an oil-heated Irish home — and what (if anything) you should actually do.

The short version:HVO is a real, lower-carbon “drop-in” alternative to kerosene, but today it's only sold in parts of Ireland and usually costs a bit more. The Renewable Heat Obligation that might one day put a renewable blend in everyone's tank is proposed, not law, and isn't expected before 2027. Nothing you need to do today— but here's the full picture.

What is HVO?

HVO — hydrotreated vegetable oil, sometimes called “renewable diesel” — is a cleaner-burning fuel made from vegetable oils and waste fats and oils. It's chemically similar enough to the kerosene most Irish oil boilers burn that it can be used as a renewable stand-in.

Its appeal is lower carbon. The figures vary by source and aren't directly comparable: industry trials report cutting lifecycle carbon by up to around 88–90%versus fossil kerosene, while SEAI's more conservative, sustainability-gated figure is at least 65% lowerthan fossil diesel oil. Either way it's a meaningful reduction — but the real number depends on how and where the fuel is made.

Can my boiler burn it?

It's a genuine “drop-in” in two cases: as a low blend with kerosene (up to roughly 20%, with no changes needed), and in newer boilers already certified for 100% HVO (for example certain Grant Vortex models).

To run an olderboiler on 100% HVO, OFTEC's guidance is that a registered technician needs to do a conversion — swapping rubber seals, flexible fuel lines and filters, and adjusting the burner. It can usually be done during a routine service, in a couple of hours (industry quotes a cost under about £500 in the UK; no confirmed Irish figure). It is not a blanket plug-and-play swap, so always have an OFTEC-registered technician confirm what your exact boiler needs.

Can I actually buy it in Ireland?

In pockets, yes. A blended product — Certa's EcoMax (80% kerosene, 20% HVO) — is on sale today as a drop-in that needs no boiler or nozzle change, but currently only in Dublin, Louth and parts of Kildare, with a wider rollout described as underway. Pure HVO for home heating isn't widely available across the country yet, and renewable fuel generally carries a price premium over ordinary kerosene.

What SEAI says

In fairness, it's worth knowing the official view. SEAI (Ireland's state energy authority) concludes that HVO, while useful elsewhere, is not the right answer for heating homes: it argues the supply is finite and better reserved for sectors with no good alternative, like aviation and heavy transport, and estimates biofuels could meet only around 1–4%of Ireland's heating demand. SEAI points homes towards heat pumps and insulation instead.

We're not here to tell you to rip out your heating — that's your call, and a big one. We just want you to have the full picture: HVO is a real option that keeps you in the oil ecosystem, and the state's energy body is sceptical about it as the long-term answer for homes. Both things are true.

The Renewable Heat Obligation (proposed)

The Renewable Heat Obligation (RHO) is a planned rule that would require companies selling heating fuels — including the kerosene that heats around 700,000 Irish homes — to make sure a small, growing share of what they sell is renewable. Think of it as the heating version of the rule that already puts some biofuel in road diesel and petrol.

Crucially, it isn't law yet. It went through public consultation in 2023, the Bill is still being drafted, and it was paused after the European Commission objected in March 2026 to a design feature favouring Irish-made biomethane. The original mid-2026 start has slipped, and commencement is now expected in 2027 at the earliest. The proposed starting level is small — around 1.5% in year one, rising to 3% — but these figures, the blend levels and the start date are all still being worked out and are not settled.

For a home heating-oil customer, the day-to-day change is modest: standard kerosene keeps flowing, and nothing about your boiler or how you order needs to change. Over time, suppliers may introduce a renewable blend, and compliance costs could nudge prices up a little — but none of that is fixed yet.

So — should you care?

It's genuinely worth knowing about, and worth a glance if you're already replacing a boiler (ask for an “HVO-ready” model, so you keep your options open). But you don't need to switch fuel, and you definitely shouldn't feel pushed to abandon oil. Availability is limited, it costs a bit more today, and the rules are still being written.

The things that actually save you money right now haven't changed: buy when it's cheap, and don't let your tank run dry.

HVO questions, answered

Can I put HVO in my oil boiler?
Sometimes, yes — but check first. HVO is a true drop-in (no boiler change) as a low blend with kerosene (up to about 20%, like Certa's EcoMax), and in newer boilers already certified for 100% HVO. To run an older boiler on 100% HVO, OFTEC's guidance is that a registered technician needs to do a conversion — swapping seals, flexible fuel lines and filters and adjusting the burner — usually during a service, in a couple of hours. Always have an OFTEC-registered technician confirm what your exact make and model needs before you switch fuel.
Can I actually buy HVO for home heating in Ireland?
Only in pockets, for now. A blended product — Certa's EcoMax (80% kerosene, 20% HVO) — is on sale today as a drop-in, but currently only in Dublin, Louth and parts of Kildare, with a wider rollout described as underway. Pure HVO for home heating is not widely available across Ireland yet.
Is HVO cheaper than kerosene?
No — renewable fuel generally costs more per litre than ordinary kerosene, because it's more expensive to produce. There isn't a reliably published Irish price premium, but expect to pay a bit more, not less. The everyday way to save on heating oil is still to compare suppliers and buy when the price dips.
Do I need to do anything because of the Renewable Heat Obligation?
No. The Renewable Heat Obligation is proposed, not law — it's still being drafted, was paused by a European Commission objection in March 2026, and isn't expected to start before 2027. Even then it would begin at a very low renewable share. Standard kerosene keeps being supplied, and nothing about your boiler or how you order oil needs to change today.
Should I switch from oil to HVO?
There's nothing urgent to do. HVO is genuinely worth knowing about — and worth asking about if you're replacing your boiler anyway (look for an 'HVO-ready' model). But availability is limited, it costs more today, and Ireland's energy authority (SEAI) doesn't see HVO as the main answer for home heating. For most people the basics matter far more right now: buy when it's cheap, and don't let your tank run dry.

Sources

Reviewed June 2026. HVO availability and the Renewable Heat Obligation are evolving — the figures here are proposed or current at that date and may change. Always check the official sources above.

The basics that still matter most

Whatever the fuel, never overpay and never run dry.

HVO or kerosene, the smart moves are the same: compare your county's suppliers for today's cheapest price, and set a free price-drop alert so you fill up when it dips.

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