OTTAWA -- Ottawa's 14-month-old light rail transit system will be shutdown on Sunday for maintenance.

OC Transpo says the full line from Blair Road to Tunney's Pasture will be out of service while work continues to install new switch heaters.

Frequent R1 replacement bus service will operate along the entire route during the O-Train closure.

The O-Train was shutdown between Hurdman and Blair stations last Sunday for work.

Rideau Transit Group is using the closure to expedite work on switch heaters and complete additional work and maintenance to improve system performance.

The Transit Commission was told earlier this month that new natural gas switch heaters are being installed in the east-end of the system.