Top 5 Things to Know Before Replacing Your Gas Boiler with a Heat Pump in 2025
- waqasdigital6
- Jul 25
- 4 min read
Quick Summary
Thinking about replacing your gas boiler with a heat pump in 2025? This guide outlines the top five things you need to know before making the switch—from property readiness to upgrade costs, installation process, and government incentives. Whether you're in Nottingham, Derby, or anywhere in the UK, Air Source Company has your back with expert advice and free grant checks.
Why Replacing Gas Boiler with Heat Pump Matters in 2025
With the UK moving toward net-zero and gas boiler phase-outs starting as early as 2025 in new builds, many homeowners are considering replacing gas boiler with heat pump systems. Heat pumps offer a cleaner, more efficient way to heat your home—and with the right setup, you can save significantly on energy bills.
Let’s explore the top five things you should know before you make the switch.
1. Can Your Home Handle a Heat Pump?
Insulation Is Key
Before installing a heat pump, your home needs to retain warmth efficiently. This means:
Loft and cavity wall insulation should be in place.
Windows should ideally be double-glazed.
Radiators and Heat Emitters
Existing radiators might need upgrading to work efficiently with lower flow temperatures of heat pumps.
Underfloor heating is ideal but not mandatory.
Outdoor and Indoor Space
Heat pumps require an outdoor unit (approx. size of an air conditioning box).
You’ll also need space inside for a hot water cylinder.
Not sure if your property is suitable? Book a free home survey with Air Source Company.
2. What Needs Changing When Switching from Gas to Heat Pump in the UK?
When switching from gas to heat pump UK systems, some internal components may need upgrading:
Pipes & Radiators: Larger bore pipes help maintain flow and efficiency.
Hot Water Cylinder: A heat pump-ready cylinder stores hot water differently than combi boilers.
Control System: A smart thermostat or zoning system enhances efficiency.
While it might sound like a big change, experienced installers (like us!) handle everything smoothly, often in just 3–4 days.
3. Cost to Replace Boiler with Heat Pump (vs. Keeping Gas)
Cost Breakdown (2025 Averages):
Option | Upfront Cost | Yearly Running Cost | Maintenance | CO2 Emissions |
New Gas Boiler | £2,500 | £1,200 | Medium | High |
Air Source Heat Pump | £10,000–£14,000 | £600–£900 | Low | Very Low |
While the cost to replace boiler with heat pump is higher upfront, long-term savings + grants make it worthwhile.
Your running costs are significantly lower with heat pumps due to higher efficiency.
With government grants, upfront costs can be reduced by up to £7,500.
4. Government Grants & Installation Timeline
Boiler Upgrade Scheme (BUS)
Up to £7,500 grant for air source heat pumps.
Available to most homeowners across England and Wales.
ECO4 Scheme
Aimed at low-income households.
May cover full cost of the heat pump installation.
Timeline:
Site survey: 1 day
Grant approval: 1–3 weeks
Installation: 2–4 days
With the right partner like Air Source Company, your transition is smooth, grant-backed, and future-ready.
5. Heat Pumps vs Gas: Long-Term Value
Heat Pumps:
300–400% efficient
Qualify for major government grants
Environmentally friendly (Net Zero compliant)
Gas Boilers:
Being phased out
Dependence on volatile gas prices
Higher emissions
Home in Derby switched in 2024: saved 42% on heating costs in first year.
Real-Life Midlands Example
Case Study – Nottingham 3-Bed Semi
Old System: 20-year-old gas boiler
New System: 8kW Daikin air source heat pump
Total cost: £11,000
Grant received: £7,500 (BUS)
Final cost: £3,500
Result: Energy bills cut by 40%, quieter operation, improved EPC rating
“Switching from gas to heat pump UK was easier than expected, and Air Source Company made it hassle-free.”
FAQs
Can I keep my old radiators when installing a heat pump?
Not always. Most systems need larger or upgraded radiators to work efficiently with low-temperature heating.
Do heat pumps work well in the UK climate?
Yes. Modern air source heat pumps work effectively even in temperatures as low as –15°C.
How long does heat pump installation take?
Typically 2 to 4 days, depending on your home's layout and upgrades needed.
Will I need a new hot water tank with a heat pump?
Yes. Most installations include a new cylinder for efficient hot water storage.
Are heat pumps cheaper to run than gas boilers?
Yes. Despite a higher upfront cost, heat pumps are more efficient and often cheaper over time.
Is replacing gas boiler with heat pump a good idea in 2025?
Absolutely—especially with grants available, rising gas prices, and carbon reduction goals.
What if my home isn't insulated enough?
Insulation upgrades are usually required. Grants like ECO4 may cover both insulation and heat pump costs.
The process of replacing gas boiler with heat pump in 2025 doesn’t have to be complicated. With support from Air Source Company, UK homeowners can futureproof their homes, reduce bills, and lower carbon emissions with confidence.
📞 Don’t wait for gas prices to rise again.
Book your free heat pump survey and grant eligibility check today with Air Source Company—your trusted partner across Nottingham, Derby, Leicester, and beyond.
👉 Book Your Free Survey or call 0115 677 7675
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