Choosing between a gas or oil boiler represents a significant decision for any homeowner. As trusted boiler installers, we’re regularly asked to help customers compare these options. This comprehensive guide breaks down the installation costs and ongoing considerations for both gas and oil boilers to help you make an informed decision.
Initial Installation Costs
The upfront expense of installing a boiler varies significantly between gas and oil systems:
Gas Boiler Installation
Basic installation costs:
- Budget combi boiler (24-27kW): £1,800-£2,500
- Mid-range combi boiler (28-34kW): £2,200-£3,000
- Premium combi boiler (35-42kW): £2,700-£3,800
- System or conventional boilers: Add approximately £200-£500 to these figures
For more detailed information on specific models, read our guide to the Worcester Bosch Greenstar 2000, a popular mid-range option.
Additional costs may include:
- Upgrading pipework: £200-£600
- Moving the boiler location: £300-£800
- System flush: £300-£500
- Smart controls: £200-£350
- Magnetic filter: £100-£200
Oil Boiler Installation
Basic installation costs:
- Budget oil combi boiler (20-25kW): £3,000-£4,200
- Mid-range oil combi boiler (25-35kW): £3,800-£5,000
- Premium oil combi boiler (35kW+): £4,500-£6,500
- Oil conventional/system boilers: Similar pricing to combi options
Additional oil-specific costs:
- External oil storage tank: £1,000-£2,000
- Oil supply line: £200-£500
- OFTEC certification: £60-£120
- Tank base preparation: £300-£600
- Regulatory compliance measures: £200-£400
Understanding the Price Difference
Several factors contribute to the higher installation costs for oil boilers:
- Equipment complexity: Oil boilers require additional components like storage tanks and supply lines
- Specialisation: Oil boiler installation requires specific expertise, often commanding premium rates
- Regulatory requirements: Oil installations must meet stricter environmental regulations
- Lower demand: Less competition in the oil boiler market can lead to higher prices
- Location factors: Rural installations may incur additional travel charges
If you’re wondering whether oil boilers are right for your home, our article on how oil boilers work provides an in-depth explanation of their operation.
Fuel Running Costs
Installation is just the beginning – ongoing fuel costs significantly impact the total ownership cost:
Gas Running Costs
- Average cost per kWh: 5-7p
- Typical annual heating bill for 3-bedroom house: £550-£750
- Efficiency of modern condensing boilers: 90-94%
- Availability: Mains supply is reliable with no need for monitoring or reordering
Oil Running Costs
- Average cost per kWh: 5-9p (varies significantly with oil prices)
- Typical annual heating bill for 3-bedroom house: £700-£1,100
- Efficiency of modern condensing oil boilers: 90-93%
- Availability: Requires monitoring, reordering and storage capacity
Oil prices fluctuate more dramatically than gas, making long-term cost predictions more challenging. However, in some off-grid areas, oil remains the most cost-effective option.
Additional Cost Considerations
Beyond installation and fuel costs, consider these factors in your decision:
Maintenance Costs
- Gas boilers: Annual service £80-£120
- Oil boilers: Annual service £120-£180 (typically more complex)
- Tank maintenance: Oil systems require additional tank inspection and maintenance
Lifespan and Replacement
- Gas boilers: Typically 10-15 years
- Oil boilers: Often 15-20 years (longer lifespan can offset higher initial cost)
Property Value Impact
- Gas connection: Often increases property value in rural areas
- Modern oil system: Can improve EPC ratings and appeal to buyers in off-grid locations
Suitability Factors Beyond Cost
Cost isn’t the only consideration when choosing between gas and oil:
Location and Infrastructure
- Mains gas availability: Obviously essential for gas boilers
- Access for oil deliveries: Tankers need suitable access to deliver to your property
- Space for oil storage: You’ll need adequate external space for an oil tank
Environmental Considerations
- Carbon emissions: Gas produces approximately 25% less CO₂ than oil
- Future-proofing: Gas networks may eventually transition to hydrogen blends
- Oil alternatives: Biofuel options are becoming more widely available
- Insulation importance: The better insulated your home, the less the fuel type matters
For more information on environmentally friendly options, see our article on how an efficient boiler can reduce your carbon footprint.
Making the Right Choice: Gas or Oil?
Based on installation and running costs:
Gas may be better if:
- You have access to the mains gas network
- Initial budget is more limited
- You prefer consistent fuel pricing
- You have limited external space
- Environmental impact is a priority
Oil may be better if:
- Your property isn’t connected to mains gas
- You have space for an oil storage tank
- You’re able to buy oil in bulk during price dips
- You prefer a longer-lasting heating system
- Your property has higher heating demands
Financing Your Boiler Installation
Whether you choose gas or oil, financing options can make installation more affordable:
- Interest-free credit for 12-24 months
- Low-interest longer-term options
- Pay monthly service plans to spread maintenance costs
- Government grants or schemes (where applicable)
Expert Guidance for Your Circumstances
While this guide provides general cost comparisons, every property has unique requirements. Our heating engineers can conduct a thorough assessment of your property and provide a detailed quotation for both gas and oil options where available.
For a personalised comparison and expert advice tailored to your specific circumstances, contact our team today. We’ll help you navigate the options and find the perfect heating solution for your home and budget.
