Thermoscup
Frequently asked questions
About Thermoscup, and about vacuum flasks in general.
What is a thermos flask?
A thermos (or vacuum flask) is a double-walled container with a vacuum gap between the walls. That vacuum barely conducts heat, so it slows down how fast a hot drink cools or a cold drink warms up - that's what keeps drinks at temperature for hours instead of minutes.
How does Thermoscup keep drinks hot or cold?
Thermoscup uses double-wall 304 stainless steel vacuum insulation, the same principle behind any quality thermos flask. It's rated to keep drinks hot for up to 12 hours and cold for up to 24 hours, so your morning coffee is still warm at lunch.
How do I clean my Thermoscup?
The wide mouth opening is designed for easy cleaning - hand wash with warm soapy water and a bottle brush, rinse thoroughly and air dry with the lid off. The tea separator lifts out to clean separately. Avoid dishwashers and abrasive cleaners, which can damage the seal and the LED display.
Is Thermoscup BPA free?
Yes. All parts that touch your drink are BPA-free, food-grade 304 stainless steel.
What is the LED display, and does it need charging?
A small digital display is built into the cap and shows your drink's live temperature in °C when you touch it - no buttons, no app, no charging cable to lose.
What's included in the box?
One Thermoscup Smart LED Flask in your chosen colour, with its removable 304 stainless steel tea separator fitted.
How is Thermoscup different from a standard insulated flask?
Most insulated flasks give you no way to check the temperature without opening the lid. Thermoscup adds a live LED display built into the cap, plus a removable stainless steel tea separator, as standard.
What is your returns policy?
30 days to return an unused Thermoscup in its original condition for a full refund. Your statutory rights are unaffected. See our Returns Policy for the full details.
Where do you deliver?
We currently deliver within the UK only. See our Shipping Policy for delivery timescales and costs.
How long can a thermos keep water hot?
A good quality vacuum-insulated thermos, like Thermoscup, typically keeps water hot for 6-12 hours depending on the starting temperature and how often it's opened. Thermoscup is rated to keep drinks hot for up to 12 hours.
How does a vacuum thermos work?
Between the inner and outer walls of a vacuum flask is a sealed gap with almost no air in it. Heat needs a medium (air, liquid or solid) to transfer through, so with barely any air in that gap, very little heat can escape - or get in. That's why a vacuum flask keeps hot drinks hot and cold drinks cold, without any batteries or electricity.
How do I clean a thermos flask?
Hand wash with warm water and washing-up liquid, using a bottle brush to reach the base. Rinse thoroughly and leave the lid off to air dry completely before storing, to avoid trapping odours or moisture.
Can I put a thermos flask in the dishwasher?
We don't recommend it. Dishwasher heat and detergent can damage seals, insulation performance and the LED display over time. Hand washing keeps a smart flask like Thermoscup working properly for longer.
What's the difference between a thermos flask and a thermos food flask?
Both use the same vacuum-insulation principle. A drinks flask (like Thermoscup) is designed for liquids through a narrower or medium opening, while a food flask has a wider mouth built for soups, stews or pasta.
