How little does it cost to run an Onyx gas stove?

Liv 3 BF Nat Gas

Input: 3.5kW (low) - 5.3kW (high)
Nominal Heat Output: 4.5kW
Remote Control Model
Efficiency Class: A
Maximum Efficiency: 94.3%†

20p

1 hour on low continuous heating

30p

1 hour on high continuous heating

80p

4 hours on low continuous heating*

£1.22

4 hours on high continuous heating

*Based on Liv3 Balanced Flue Natural Gas model, running at 4 hours on low input of 3.5kW. The costs presented are based on the average UK cost per unit of gas (including VAT) from 1st April 2026, for customers on the default tariff. Figures generated are for typical domestic consumption paying by direct debit and will vary based on actual household usage (5.74p per kWh, OFGEM, Energy Price Cap, https://www.ofgem.gov.uk/energy-price-cap ). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Maximum efficiency is achieved when running product on high output setting.

Northern Ireland:

27p

1 hour on low continuous heating

40p

1 hour on high continuous heating

£1.07

4 hours on low continuous heating*

£1.62

4 hours on high continuous heating

*Based on Liv3 Balanced Flue Natural Gas model, running at 4 hours on low input of 3.5kW. Costs presented are based on the unit price of gas on a direct debit budget plan tariff with SSE Airtricity, with a fixed unit price of 7.627p/kWh inc VAT (https://www.sseairtricitygasni.com/tariff-and-payment-options/; Accessed 25/02/2026). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Maximum efficiency is achieved when running product on high output setting.

How little does it cost to run an Onyx gas fire?

Avanti Gas Fire♦

Input: 3.6kW (low) - 6.4kW (high)
Nominal Heat Output: 4.5kW
Remote Control Model
Efficiency Class: D
Maximum Efficiency: 78.4%†

21p

1 hour on low continuous heating

37p

1 hour on high continuous heating

83p

4 hours on low continuous heating*

£1.47

4 hours on high continuous heating

*Based on Avanti Gas 65 Conventional Flue Natural Gas model, running at 4 hours on low input of 3.6kW. The costs presented are based on the average UK cost per unit of gas (including VAT) from 1st April 2026, for customers on the default tariff. Figures generated are for typical domestic consumption paying by direct debit and will vary based on actual household usage (5.74p per kWh, OFGEM, Energy Price Cap, https://www.ofgem.gov.uk/energy-price-cap ). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Maximum efficiency is achieved when running product on high output setting.
♦Based on Avanti Gas 65 Conventional Flue Natural Gas model.

Northern Ireland:

27p

1 hour on low continuous heating

49p

1 hour on high continuous heating

£1.10

4 hours on low continuous heating*

£1.95

4 hours on high continuous heating

*Based on Avanti Gas 65 Conventional Flue Natural Gas model, running at 4 hours on low input of 3.6kW. Costs presented are based on the unit price of gas on a direct debit budget plan tariff with SSE Airtricity, with a fixed unit price of 7.627p/kWh inc VAT (https://www.sseairtricitygasni.com/tariff-and-payment-options/; Accessed 25/02/2026). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Maximum efficiency is achieved when running product on high output setting.
♦Based on Avanti Gas 65 Conventional Flue Natural Gas model.

How little does it cost to run an Onyx gas fire?

Eclipse Gas*

Input: 5.1kW (low), 7.3kW (high)
Nominal Heat Output: 5.1kW
Remote Control Model
Maximum Efficiency: 78%†
Efficiency Class: D

29p

1 hour on continuous heating

42p

1 hour on high continuous heating

£1.17

4 hours on low continuous heating*

£1.68

4 hours on high continuous heating

*Based on Eclipse 60HL Conventional Flue Natural Gas model, running at 4 hours on low input of 5.1kW. The costs presented are based on the average UK cost per unit of gas (including VAT) from 1st April 2026, for customers on the default tariff. Figures generated are for typical domestic consumption paying by direct debit and will vary based on actual household usage (5.74p per kWh, OFGEM, Energy Price Cap, https://www.ofgem.gov.uk/energy-price-cap ). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Maximum efficiency is achieved when running product on high output setting.

Northern Ireland:

39p

1 hour on continuous heating

56p

1 hour on high continuous heating

£1.56

4 hours on low continuous heating*

£2.23

4 hours on high continuous heating

*Based on Eclipse 60HL Conventional Flue Natural Gas model, running at 4 hours on low input of 5.1kW. Costs presented are based on the unit price of gas on a direct debit budget plan tariff with SSE Airtricity, with a fixed unit price of 7.627p/kWh inc VAT (https://www.sseairtricitygasni.com/tariff-and-payment-options/; Accessed 25/02/2026). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Maximum efficiency is achieved when running product on high output setting.

Why choose an Onyx stove or fire?

There are lots of fantastic reasons to choose an Onyx luxury gas or electric stove or fire for your home.

Over 40 Years of Expertise

As part of the Stovax Heating Group, Onyx represents the pinnacle of more than four decades of British design and engineering expertise. Every fire and stove is born in our state-of-the-art research and development laboratories, and incorporates industry leading technology and design.
Effortless Control

All of our stunning stoves and fires come with an intuitive remote handset for effortlessly controlling your Onyx stove or fire from the comfort of your armchair. What’s more, many of our electric fires are controllable with compatible iOS and Android smartphones via an innovative app.
Unparalleled Ambience

Many of our electric stoves and fires boast a plethora of different flame and lighting effect combinations, thanks to our advanced Chromalight® Immersive LED systems. When coupled with our authentic and lifelike log sets, Onyx electric fires deliver a truly unparalleled fireside ambience.
Highly Efficient

Onyx gas stoves and fires are designed to be as efficient as possible, with some offering up to a 94.3% efficiency rating. Likewise, our electric stoves and fires are designed with smart Ecodesign energy saving features such as Open Window Detection, to maximise energy efficiency.

How little does it cost to run an Onyx electric fire?

Avanti Electric Range†

Input: 1.0kW (low) - 2.0kW (high)
Output: 1.0kW (low) - 2.0kW (high)
      (depending on usage of heat & effects)
Enjoy with or without heat
Media Wall Compatible

5p

4 hours flame effect only

26p

1 hour on low continuous heating

51p

1 hour on high continuous heating

£1.06

4 hours on thermostatically maintained heat*

*Based on running the fire for 4 hours, with heat on for 50% duty cycle due to thermostatic control, and flame effects for the full duration. Based on the average UK cost per unit of electric (including VAT) from 1st April 2026, for customers on the default tariff. Figures generated are for typical domestic consumption paying by direct debit and will vary based on actual household usage (24.67p per kWh, OFGEM, Energy Price Cap, https://www.ofgem.gov.uk/energy-price-cap). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Figures based on the Avanti Electric 110RW Fire

Northern Ireland:

6p

4 hours flame effect only

32p

1 hour on low continuous heating

62p

1 hour on high continuous heating

£1.30

4 hours on thermostatically maintained heat*

*Based on running the fire for 4 hours, with heat on for 50% duty cycle due to thermostatic control, and flame effects for the full duration. Based on the cost per unit of electric (including VAT) for customers on the Power NI Monthly Direct Debit plan with Energy Online (30.22p/kWh as of 25th February 2026 https://powerni.co.uk/compare-plans-and-prices-recommended-plan/?featureOne=Bill%20Pay&featureTwo=Standard%20Rate). Figures generated are for typical domestic consumption paying by monthly direct debit and will vary based on actual household usage. Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.
†Figures based on the Avanti Electric 110RW Fire

How little does it cost to run an Onyx electric fire?

Fusion 150RW Electric Fire

Input: 1.0kW (low) - 2.0kW (high)
Output: 1.0kW (low) - 2.0kW (high)
      (depending on usage of heat & effects)
Enjoy with or without heat
Media Wall Compatible

4p

4 hours flame effect only

26p

1 hour on low continuous heating

50p

1 hour on high continuous heating

£1.05

4 hours on thermostatically maintained heating*

*Based on running the fire for 4 hours, with heat on for 50% duty cycle due to thermostatic control, and flame effects for the full duration. Based on the average UK cost per unit of electric (including VAT) from 1st April 2026, for customers on the default tariff. Figures generated are for typical domestic consumption paying by direct debit and will vary based on actual household usage (24.67p per kWh, OFGEM, Energy Price Cap, https://www.ofgem.gov.uk/energy-price-cap ). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.

Northern Ireland:

5p

4 hours flame effect only

31p

1 hour on low continuous heating

62p

1 hour on high continuous heating

£1.28

4 hours on thermostatically maintained heating*

*Based on running the fire for 4 hours, with heat on for 50% duty cycle due to thermostatic control, and flame effects for the full duration. Based on the cost per unit of electric (including VAT) for customers on the Power NI Monthly Direct Debit plan with Energy Online (30.22p/kWh as of 25th February 2026 https://powerni.co.uk/compare-plans-and-prices-recommended-plan/?featureOne=Bill%20Pay&featureTwo=Standard%20Rate). Figures generated are for typical domestic consumption paying by monthly direct debit and will vary based on actual household usage. Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.

How little does it cost to run an Onyx electric fire?

Orbit Electric Fire

Input: 0.75kW (low) - 1.5kW (high)
Output: 0.75kW (low) - 1.5kW (high)

      (depending on usage of heat & effects)
Enjoy with or without heat
Ceiling-hung fire

2p

4 hours flame effect only

19p

1 hour on low continuous heating

38p

1 hour on high continuous heating

77p

4 hours on thermostatically maintained heating*

*Based on running the fire for 4 hours, with heat on for 50% duty cycle due to thermostatic control, and flame effects for the full duration. Based on the average UK cost per unit of electric (including VAT) from 1st April 2026, for customers on the default tariff. Figures generated are for typical domestic consumption paying by direct debit and will vary based on actual household usage (24.67p per kWh, OFGEM, Energy Price Cap, https://www.ofgem.gov.uk/energy-price-cap). Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.

Northern Ireland:

3p

4 hours flame effect only

23p

1 hour on low continuous heating

46p

1 hour on high continuous heating

94p

4 hours on thermostatically maintained heat*

*Based on running the fire for 4 hours, with heat on for 50% duty cycle due to thermostatic control, and flame effects for the full duration. Based on the cost per unit of electric (including VAT) for customers on the Power NI Monthly Direct Debit plan with Energy Online (30.22p/kWh as of 25th February 2026 https://powerni.co.uk/compare-plans-and-prices-recommended-plan/?featureOne=Bill%20Pay&featureTwo=Standard%20Rate). Figures generated are for typical domestic consumption paying by monthly direct debit and will vary based on actual household usage. Does not include any costs relating to product maintenance and servicing. Prices rounded to nearest whole pence.

Onyx

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