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Industrial heating oil - Therma35

Ideal for heating, boiling and drying applications.
Simply drop it in and go.

What is Therma35 industrial heating oil?​

Therma35 is a drop-in alternative to conventional Class A2 gas oil. Ideal for use in commercial boilers, heaters, driers and furnaces.
With no equipment modifications required and a long storage life, it’s a cost-effective choice for all kinds of businesses. Plus, buy Therma35 in bulk today, and you can safely store it all year round.

Industrial heating oil - Therma35

Therma35 is a drop-in alternative to conventional Class A2 gas oil. Ideal for use in commercial boilers, heaters, driers and furnaces.
With no equipment modifications required and a long storage life, it’s a cost-effective choice for all kinds of businesses. Plus, buy Therma35 in bulk today, and you can safely store it all year round.

Cost Blue Icon

More cost-efficient than standard 10ppm gas oil

Blue Burner Performance Icon

Doesn't compromise performance

Drop In Blue Icon

Drop-in alternative - no equipment modification

Winter Blue Snowflake Icon

Winter grade all year round means no waxing

Blue Shield Tick Icon

FAME-free - no added biofuel giving peace of mind

Fuel Storage Barells Blue Icon

Safe to store all year round

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Therma 35 questions? We’ve answered them.

Do you want to know what applications Therma35 is best used for? And how it can benefit you and your business? Get answers to all your burning Therma35 questions from our team of experts.


Top tips for winter operations

As the nights draw in, and we start seeing the first frosts of the year, businesses up and down the country are preparing for winter. From choosing the right heating oil to managing your supply during a cold snap, we’ve got expert advice to help you through the season.


How does Therma35 offer value for money?

As well as burning more slowly than conventional gas oil, Therma35 industrial heating oil offers a range of added-value benefits. Unlike red diesel, the fuel’s long-term storage stability, winter-grade and zero bio content means it can be bought in bulk and stored all year round without the risk of spoilage, interruption or waxing.


Delivering top of the class service

Royal Hospital School gained a range of added value benefits since changing supplier. A fixed-price contract has supported improved resource planning, while the locality of the Certas Energy depot in Ipswich has ensured a reliable fuel supply and a swift response to potential queries.


Cost-effective commercial heating

One Devonshire-based leisure organisation saved over £2,000 in just 3 months, simply by switching from gas oil to Therma35 for their commercial heating applications.

Get in touch with our team to swap your fuel today.

Therma35 industrial heating oil FAQs

Here, we delve into some of the most frequently asked questions around Therma35 to see if it really can take the heat.

Contact us today for a personalised quote and discover how Therma35 can help fuel your business, the right way.

Industrial heating oil – available through Certas Energy under the brand name Therma35 – is a highly cost-efficient drop-in alternative to conventional Ultra Low Sulphur Class A2 gas oil/red diesel. Because it complies with government regulations for use in a range of commercial and non-commercial heating applications, it is already a highly popular solution across various sectors.

Industrial heating oil can be used for any heating purposes where gas oil would otherwise be used, without any modifications to equipment or machinery. It is restricted to use in heating applications only, and cannot be used for powering mobile or stationery plant or machinery. However, the heating applications Therma35 has to offer are diverse, including:
• Space heating and central heating; for example in apartment blocks, commercial buildings, schools, hospitals and site cabins
• Drying and industrial heating; for example in an agricultural context. This includes use in grain driers on farms, as well as for metal processing and tarmac manufacture
• Industrial boiler plant; powering various heat-related treatments that are required at food and beverage manufacture facilities, abattoirs, dairies, distilleries and animal feed mills.

Gas oil must contain specific levels of cetane in order to be suitable for use in modern diesel engines.
Because Therma35 is only permitted for use in heating applications, there is no need for the costly addition of cetane or sulphur removal. Industrial heating oil is therefore more cost-efficient to produce, while still remaining completely compliant. It also offers better value for every-day use, because industrial heating oil burns more slowly than standard gas oil.

The rules around the applications that gas oil/red diesel can be used for are changing in April 2022: click here to find out more.

A particularly important benefit of Therma35 is its stability and efficiency. Industrial heating oil is a winter-grade solution with a long shelf-life that is safe to store all year round, because it contains no bio content. Companies can therefore stock up in advance to ensure they are well-prepared when a cold snap hits, without worrying about spoilage due to microbial content, interruption or waxing. “Waxing” refers to the build-up of wax crystals in fuel that can clog pipes and therefore may lead to equipment failure.

Getting ready and stocking up in time for winter is especially important when it comes to heating oil: a sudden drop in temperature due to a lack of supply may not only disrupt production, but it can also severely damage equipment or even structures in the event of a burst pipe.

The great news is that the process of switching over to Therma35 need not be a complex one. It is a drop-in alternative that is entirely miscible with red diesel, so it not necessary to clean out or empty your gas oil tank before topping up with Therma35. However, since Therma35 is only permitted for heating applications, it should only be mixed with gas oil that is intended exclusively for heating.

Certas Energy is here to help you fuel a more efficient, successful future for your business. Therma35 and kerosene are both readily available as part of an extensive portfolio of fuels, lubricants, additives and heating oils – everything you need to keep your business moving, the right way. As the UK’s largest fuel distributor, Certas Energy has the unrivalled infrastructure to deliver regular supply of high-quality industrial heating oil in large quantities, serving customers across sectors and throughout the whole UK.

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