Reviewed by the Quel Tap product team. Last updated: September 2026.
Quick answer
Based on Quel Tap’s own published figures, a 2.4 Litre boiler uses around 0.75kWh of electricity over 24 hours. At the current Ofgem price cap of 26.11 pence per kWh, that works out to roughly £71 a year in electricity, plus around £112 a year for filters on a standard six-month subscription plan. Together, that’s a little under £185 a year, or about 50p a day, to run the tap and keep it filtered. Your own number will vary based on your tariff and how often the boiler’s used, so the workings out are laid out in more detail below.
Where the cost actually comes from
Running costs on a boiling water tap come from two places: keeping the reserve of water hot around the clock, and topping it back up each time water is drawn off. There’s a third, smaller cost that most people forget to budget for, and that is the replacement filters you will need every 6 months.
From our own research, a 2.4 Litre boiler uses around 0.75kWh over 24 hours to do this. That figure already accounts for normal daily use, not just sitting idle, so it’s a more honest starting point than the very low standby-only figures that are sometimes quoted, which don’t reflect what a boiler actually draws once a household is using it on a daily basis
Working it out for your own home
The calculation is the same one used above, and you can run it with your own numbers in three steps:
- Find the daily energy use. For any Quel Tap model, that is roughly 0.75kWh a day, as per the figure above.
- Multiply by your electricity rate. Check your electricity bill or tariff for your rate in pence per kWh, as not everyone is on the same rate as the Ofgem cap.
- Multiply the daily cost by 365, then add filter costs separately, since they’re billed every six months rather than daily.
| Step | Formula | Example (at 26.11p/kWh) |
|---|---|---|
| Daily electricity cost | 0.75kWh x your rate | 0.75 x 26.11p = 19.6p |
| Annual electricity cost | Daily cost x 365 | 19.6p x 365 = £71.48 |
| Annual filter cost | £56 x 2 (every 6 months) | £112 |
| Total estimated annual cost: | £183 |
A worked example, using real numbers
As of August 2026, the Ofgem price cap sets the average Direct Debit electricity rate at 26.11p per kWh. Using Quel Tap’s own 0.75kWh figure, that’s 19.6p a day, or roughly £71.48 a year in electricity, before filters. Add a standard filter subscription at £56 every six months, and the full running cost comes to around £183 a year, or a little under 50p a day.
That’s a genuine estimate rather than a marketing minimum, and it will move with your tariff. Anyone on a fixed deal below or above the current cap should use their own rate in the table above rather than the Ofgem figure.
How that compares to a kettle
The Energy Saving Trust puts the cost of a full kettle boil at around 7p. Boiled four times a day, that’s roughly £102 a year, and that’s before accounting for the overfilling most households do, which the Trust estimates adds a further £10 a year on average. We’ve covered the fuller kettle-versus-tap picture, including convenience and worktop space, in our Boiling Water Tap vs Kettle blog; the short version is that frequent daily use is where the tap’s numbers start to look better than a kettle’s, while very light use can go either way.
What actually changes your number
A few things move the total more than people expect:
- Your tariff matters more than your tap. The difference between a cheap fixed deal and the standard variable rate can shift the annual electricity figure by around £20 or more, without anything about the tap itself changing.
- Being away from home helps. Quel Tap advises switching the boiler off entirely if you’re away for more than two days, which avoids paying to keep a reserve hot that nobody’s using.
- Filters are a fixed cost regardless of usage, at roughly £112 a year on subscription, so light users will find filters make up a larger share of their total running cost than electricity does.
The everyday result
None of this is a hidden cost; once it’s written out, it’s a straightforward one. Roughly £183 a year, at current prices, covers the electricity and the filters for a tap that’s ready the moment you want it. Water, beautifully controlled.
If you’re weighing these figures up against a specific model, it’s worth browsing our range of boiling water taps to see the boiler size and functions each one comes with, since that’s what your own number will actually depend on.
Frequently Asked Questions (FAQs)
Does a bigger boiler cost more to run?
Larger boilers hold more water at temperature, so they typically use somewhat more standby energy than smaller ones, though the difference is modest compared with the impact of your electricity tariff.
Will a fixed-rate tariff change my running cost?
Yes, the electricity portion of the cost scales directly with your rate per kWh. A cheaper fixed deal than the current Ofgem cap will lower the figure, and a more expensive one will raise it.
Can I reduce running costs by lowering the temperature setting?
Yes. The temperature setting can be adjusted to reduce the standby temperature by 3 to 9 degrees before the boiler reheats, which uses less energy if you don’t need water at a full 98°C every time.
How much do filters add to the total running cost?
Around £112 a year on a standard six-month subscription at £56 per set, which is a fixed cost regardless of how often the tap is used.
Is the running cost the same across all Quel Tap models?
The published 0.75kWh figure is a typical estimate across our entire range; however, larger-capacity boilers and models with chilled or sparkling functions may use somewhat more, so it’s worth checking the specification for your chosen model.