Over the course of the years the boiler has been replaced several times.

The report says that 348 boilers and 332 roofs must be replaced.

The boilers on all the surviving engines were replaced between 1892 and 1897.

For example, the original boiler was replaced in 1927.

In many cases, the boilers were later completely replaced.

In due course, boilers will be replaced with more efficient models, but only when those installed reach the end of their useful life.

She was reclassified as a corvette in 1877 and the following year her boilers were replaced.

As part of a central plant project, the boilers and chillers are replaced with more efficient models.

Plans were made for a radical reconstruction to be done while her boilers were being replaced.

The department now spends almost $2.5 billion a year just to upgrade old public housing projects, replacing boilers and roofs.