Real-World Cost Savings from Switching to ASHPs

Right, let’s talk actual numbers. Not the theoretical stuff you see in brochures, but what people are really paying after we’ve fitted their heat pumps. Been keeping track of this for years because customers always ask “what will it actually cost to run?”

The Wakefield Semi (2022 Installation)

Before: 3-bed semi, built 1980s, decent insulation

Gas boiler from 2015, seemed efficient enough
Winter gas bills: £145-160 per month (October to March)
Annual heating costs: roughly £1,100

After: Same house, same family, same heating habits

Heat pump running costs: £85-95 per month in winter
Annual heating costs: around £650
Yearly saving: £450

The family were dead surprised. Kept expecting a massive electric bill that never came. Mrs K said “I keep checking the meter thinking it’s broken.”

The Victorian Terrace in Leeds (2023 Installation)

Before: 2-bed terrace, 1890s build, single glazing, minimal insulation

Ancient gas boiler, probably 15 years old
Struggled to heat the place properly
Winter bills: £120-140 per month
Always cold upstairs, annual costs: £950

After: Heat pump sized properly for the building

Electric heating costs: £75-85 per month
House actually warm for the first time in years
Yearly saving: £280
Plus: Upstairs bedrooms finally comfortable

Bloke said “wish we’d done it years ago.” The difference wasn’t just money – the house actually worked as a heating system for once.

The Rural Farmhouse (Oil to Heat Pump, 2023)

Before: 4-bed farmhouse, middle of nowhere, oil heating

2,500 litres of oil per year at £0.65 per litre
Annual heating costs: £1,625
Pain to get deliveries, tank took up half the garden

After: Air source heat pump with buffer tank

Annual electricity for heating: £950
Yearly saving: £675
Bonus: No more oil deliveries, got the garden back

Customer reckons it’s the best money he’s ever spent. “No more watching oil prices, no more running out on bank holidays.”

The Modern Detached House (2024 Installation)

Before: 4-bed new build, supposedly efficient

Combi boiler, only 5 years old
Good insulation, thought bills would be reasonable
Winter gas costs: £180-200 per month
Annual heating: £1,350

After: Heat pump with weather compensation controls

Winter electricity costs: £110-125 per month
Annual heating: £850
Yearly saving: £500

Family were proper skeptical at first. “How can it be cheaper than gas?” But the numbers don’t lie.

The Surprising One – 1960s Bungalow (2024)

Before: 2-bed bungalow, thought it was hopeless case

Solid walls, single glazing, electric storage heaters
Eye-watering electric bills: £220 per month in winter
Annual heating costs: £1,650

After: Heat pump with careful sizing

Monthly winter costs: £95-110
Annual heating: £750
Yearly saving: £900

Biggest saving we’ve ever recorded. Customer nearly cried when she got her first winter bill.

What These Numbers Actually Mean

Average saving across all installations: £480 per year Payback period (after £7,500 government grant): 4-6 years typically Best case: £900 yearly saving (electric storage heater replacement) Worst case: £200 yearly saving (very efficient gas boiler replacement)

The Reality Check – What Affects Your Savings

Size of your current bills: Bigger bills = bigger savings. If you’re spending £2,000 a year on heating, you’ll save more than someone spending £800.

What you’re replacing: Oil heating gives massive savings. Brand new efficient gas boiler, not so much.

How you use heating: Family that heats whole house 24/7 saves more than someone who just heats one room in evenings.

Local electricity/gas prices: Changes constantly, but heat pumps usually stay ahead because they’re so efficient.

The Hidden Costs Nobody Mentions

Slightly higher electricity standing charge: About £50 more per year if you switch to economy tariff.

Annual service: £150-200 yearly. Gas boiler service costs similar, so call it even.

Occasional repairs: Like any heating system, things break. Budget £200-300 over 5 years.

Bottom line: Even with extra costs, you’re still saving £300-600 annually.

The Tariff Game-Changer

Economy 7 tariffs: Cheap electricity overnight

Heat your house when power costs 7p per kWh instead of 28p
Smart controls charge up thermal store during cheap hours
Can double your savings if you’re clever about it

Mrs B in Harrogate switched to Octopus Go tariff. Saves an extra £200 per year just on timing when her heat pump runs.

What About Summer?

Heat pumps do hot water too. Numbers from actual customers:

Gas combi boiler hot water: £25-30 per month year-round Heat pump hot water: £18-22 per month Summer savings: Extra £60-80 per year

Not massive, but it all adds up.

The Ones That Didn’t Work Out

Honest bit: Not every installation saves money straight away.

Problem house 1: Massive Victorian pile, terrible insulation, oversized heat pump

Savings: Only £150 per year
Issue: System was sized wrong, cycling too much

Problem house 2: Customer kept fiddling with controls

First year: Higher bills than gas
After we reset everything properly: £400 yearly saving

Lesson: Get it sized right, set it up properly, then leave it alone.

Real Customers, Real Quotes

“First winter bill was half what we expected” – Sheffield semi

“Best decision we ever made” – Rotherham bungalow

“Why didn’t anyone tell us about these years ago?” – Doncaster terrace

“Payback was faster than promised” – Barnsley farmhouse

The Honest Truth About Savings

Most customers save £300-600 per year once everything’s running properly. Takes a couple of months to get the settings right, then it just works.

If you’re spending more than £1,000 yearly on heating, you’ll probably save decent money. Less than that, savings are smaller but still worthwhile.

Want to know what you’d actually save? Give us your last 12 months of energy bills and we’ll work out real numbers for your house.

No guesswork, no marketing fantasy. Just what the meter will actually say.