The short answer
Use the exact dryer’s declared cycle energy or a compatible measurement, then multiply by your tariff and routine. Compare the purchase premium with annual electricity savings. Two efficient heat-pump models can differ only slightly in energy, leaving a higher price unrecovered over the chosen period.
A heat-pump dryer does not have one universal running cost
Use an exact model’s declared energy or a complete-cycle measurement, then apply your tariff and routine. Capacity, programme and load basis matter. Heat-pump technology alone does not supply a kWh input or establish that a price premium will pay back.
For a measurement-based example, read the published US household dryer case study. It uses externally collected field measurements and separately stated cost assumptions. Its laundry-load basis differs from the standardized programme declarations below.
Two Bosch GB product sheets dated 22 September 2026 provide a compatible 9 kg weighted eco-drying example:
| Model | Capacity | Declared weighted eco energy | Manufacturer-listed base price observed 3 October 2026 |
|---|---|---|---|
| WQH246DRGB | 9 kg | 0.92 kWh/cycle | £849 |
| WRB247C9GB | 9 kg | 0.79 kWh/cycle | £1,199 |
The prices were VAT-inclusive manufacturer listings on that date, rather than live checkout quotes. Delivery, installation, promotional discounts and collection are excluded. Check your actual quotes before a purchase decision.
The energy figures are manufacturer declarations, not independent Watt & Home measurements. A weighted eco-cycle figure describes a standardized load mix. It is not the energy of every full 9 kg load or of a quick programme.
Price the declared cycles at your routine
Assume three cycles each week, 52 weeks and an illustrative £0.28/kWh:
| Modeled annual result | WQH246DRGB | WRB247C9GB |
|---|---|---|
| Cycles | 156 | 156 |
| Energy | 143.52 kWh | 123.24 kWh |
| Electricity | £40.19 | £34.51 |
The difference is 20.28 kWh/year, or £5.6784/year, displayed as £5.68. The calculation retains precision; subtracting displayed rounded values can differ by a penny. Idle energy outside the declared cycle basis is excluded.
At six cycles/week, savings double to £11.3568/year. At one cycle/week, they fall to £1.8928/year. These frequencies are assumptions, rather than claims about an average household.
Test whether the extra purchase price earns its way back
The dated base-price difference is £350. At three cycles/week and £0.28/kWh:
£350 ÷ £5.6784/year = about 61.6 years of simple extra-price payback.
This arithmetic does not forecast either dryer’s lifetime. It shows that the electricity difference is too small to recover that assumed price premium within a five-year comparison.
| Five-year purchase + modeled cycle electricity | Cost |
|---|---|
| WQH246DRGB | £1,049.93 |
| WRB247C9GB | £1,371.54 |
| Lower-energy option costs more by | £321.61 |
The more expensive appliance may offer features you value. Compare the programme, fit, noise, controls and confirmed total delivered prices. Energy alone does not price those benefits. Financing, repairs, failure, resale and future tariff changes are excluded from this calculation.
If a promotion changes the price difference to £50, simple electricity-savings payback at the same routine becomes about 8.8 years. That £50 difference is an illustrative scenario, not a reported promotion.
A different comparison can give a much larger saving
An older documented 8 kg standard-cotton full-load comparison uses WTN83203GB at 4.71 kWh and heat-pump WTH85223GB at 1.87 kWh. At three full-load cycles/week and £0.28/kWh, those quantities differ by 443.04 kWh/year, or £124.05/year.
The manufacturer marks those reference models unavailable. They explain the arithmetic rather than provide a current buying shortlist. Their standard-cotton full-load figures must not be substituted for the weighted eco figures in the 9 kg example above.
With illustrative prices of £500 and £750, that older example’s £250 premium gives about 2.0 years of payback. Its five-year totals are £1,528.66 and £1,158.41. A different model pair, test basis and price gap can change the conclusion substantially.
Keep annual, per-cycle and per-100-cycle quantities distinct
Older dryer annual figures use a specified routine and low-power consumption. Dividing such a figure by 160 does not recreate separately declared full-load cycle energy.
EU labels introduced from July 2025 use A–G ratings and energy per 100 eco drying cycles. Great Britain has its own transition arrangements; Northern Ireland needs its applicable guidance. Read the actual printed unit and the GB/NI guide before choosing a field.
A sheet already stated as 0.92 kWh/cycle goes directly into the per-cycle field. Do not divide it by 100 again. The dryer-label guide explains the test basis, and the EU workflow uses EU model documents separately.
Choose the calculator that matches your decision
Load the current GB example below into the two-purchase comparison, then replace the dated price snapshot and illustrative tariff with your own inputs. The documented examples link the original product sheets and individual running-cost tools.
For a working dryer you could keep, use replacement payback. That starts with the full net replacement outlay, rather than a price difference between two new appliances.
Use assumption scenarios to explore chosen energy and tariff changes. For a different programme or your own load mix, record completed-cycle kWh and retain the measurement conditions.