Water vending machines — ฿1 for ~2 litres
Coin-operated RO + UV machines — everywhere in Thailand
Across Thailand you find blue or white machines outside shops, apartments and on street corners. For ฿1 you get about 2 litres, filtered with reverse osmosis and UV sterilisation. Locals refill large bottles for daily use. Cost per litre: ฿0.50 — among the cheapest options.
Source: ExpatInsurance.com / Water-Insider.com 2026
Contamination in 28.5% of tested machines
A study of 123 samples from Bangkok machines found coliform bacteria in 28.5%. The cause: filter maintenance. Machines cleaned fewer than three times a year had 14.5× higher odds of contamination.
A journalist tested a machine next to a 7-Eleven and found no maintenance at all. Stagnant water in a warm tank without UV means bacterial growth.
Source: Public Health of Indonesia 2020 / Water-Insider 2026
Checklist from Thailand’s public health guidance
- Look for a maintenance label with company name and last service date
- Machine should look clean and stand away from waste bins
- Water should be clear and odourless
- Nozzle interior should be stainless steel (not plastic)
- UV lamp present = extra safety
- Busy locations = more use = less stagnant water = safer
Source: ExpatInsurance.com / Dr. Danai, Dept. of Public Health Thailand