Montrose Infirmary is temporarily closed and six inpatients from the GP ward have been transferred to Brechin Infirmary following a boiler breakdown.
The failure has resulted in no heating or hot water facilities throughout the building.
An NHS Tayside spokesperson said: “As ensuring safe care for these patients is a priority, they were moved earlier today (Thursday) and all families have been informed.
“Anyone calling the ward will be transferred directly to Brechin Infirmary.
“There were no maternity patients at Montrose Infirmary this morning and maternity services have now been transferred to Arbroath Infirmary.
“Midwives from Montrose Infirmary are now temporarily based at the Links Health Centre in Montrose to enable them to continue to provide ante and post-natal services locally.
“Montrose midwives are also contacting all local mothers-to-be who are 28 weeks pregnant and above to advise of the change to services.
“Maternity phone lines have been diverted to Arbroath Infirmary and signage will be put on the doors at Montrose Infirmary to advise any visitors of the closure.
“NHS Tayside apologises for any inconvenience the transfer of services has caused and will issue further updates on the situation when available.”