The soldier's commanding officer Lieutenant Colonel Steve Davies said: "The tragic death of this committed and professional sapper has hit the Task Force Helmand Engineer Group hard; the Corps has lost a rising star, and his squadron has lost a respected comrade and friend.
"At this most difficult time, our thoughts and prayers are with his family and loved ones."
The incident did not involve enemy action and the serviceman's next of kin have been informed.
The soldier is the first to die in Afghanistan in 2014.
A total of 448 British forces personnel or Ministry of Defence civilians have died while serving in Afghanistan since the start of operations in October 2001.
According to the MoD, of these, 404 were killed as a result of hostile action while 44 are known to have died either as a result of illness, non-combat injuries or accidents, or have not yet officially been assigned a cause of death pending the outcome of an investigation.
The majority of British forces are in Helmand Province, in the south of the country, but some also operate elsewhere, including in and around the capital, Kabul.
The drawdown of British troops is under way, and all combat troops are due to have left by the end of the year.
Based in Hohne, north Germany, 32 Engineer Regiment supports 7th Armoured Brigade,.