Night tariffs and safety: what I run overnight at 6.6p
On a cheap night rate, a wash that costs about 18p in the day costs about 4.6p overnight. Cheap power is worth using — but safety comes before savings.
We're on a dual-rate tariff with Octopus Energy: 6.6p per kWh for six hours overnight, and the standard rate the rest of the day. Our washing machine and dishwasher have delay-start timers, and our heated clothes airer dries the washing overnight. This page shares what works for our home — it's one household's experience, not professional fire or electrical advice.
Day rate vs night rate
| Appliance | Day (26p) | Night (6.6p) |
|---|---|---|
| Washing machine40°C cycle on a delay timer | ~18p | ~4.6p |
| DishwasherEco cycle on a delay timer | ~23p | ~5.9p |
| Heated clothes airer300W, about 8 hours overnight | ~62p | ~16p |
Electricity only, using illustrative energy figures. Night rates, hours and day rates vary by supplier and plan — check your own tariff before changing habits. On a single-rate tariff there's nothing to gain from running things at night.
Safety comes first
UK fire services and Electrical Safety First advise against leaving appliances running overnight or while you're out. Cheap electricity never makes a risk worth taking — if you're not comfortable running something while you sleep, don't.
The one rule I never bend: don't run a tumble dryer while you're asleep or out. Lint and a large heating element are a known fire risk, and we don't run ours overnight.
- Fit working smoke alarms on every floor, and consider a heat alarm in the kitchen or utility room. Test them monthly.
- Plug big appliances straight into the wall — never into an extension lead or adaptor.
- Register appliances and check for recalls at the manufacturer's site or registermyappliance.org.uk.
- Keep machines maintained: clean filters and seals, and stop using anything that smells hot, sparks or trips the electrics.
- Use heated airers as the maker intends: on a hard, stable floor, away from curtains and bedding, never covered beyond the instructions.
This is general information from one household's experience, not a fire risk assessment or professional electrical advice. Always follow your appliance's manual and official guidance from your local fire and rescue service. You're responsible for decisions about your own home.
Day prices at 26p per kWh · night prices at 6.6p per kWh
See how washing, drying and cooking compare — all priced the same way.
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