Shoppers and staff at Marks and Spencer in Gloucester had to be evacuated yesterday.
The store was partially closed after a fault to the drainage and refrigeration systems was discovered.
An M&S spokesperson said yesterday: "We would like to apologise to our customers for any inconvenience caused as a result of the temporary closure of the Eastgate Street store today.
"A fault to the drainage and refrigeration systems caused the basement shop floor to remain shut throughout the day and the remainder of the store was closed between 9.30am and 12.30pm.
"All areas of the store are expected to be open as normal tomorrow."
The store has now reopened fully.