1 In the Format Cells dialog box, click Color, and then click the White square. 2  Click OK in the Format Cells dialog box, and then click OK in the Conditional Formatting dialog box. 3  Note Because you selected column A in step 2, all the cells in column A were formatted with this conditional format. In the Format Cells dialog box, click Color, and then click the White square. 2  Click OK in the Format Cells dialog box, and then click OK in the Conditional Formatting dialog box. 3  Note Because you selected column A in step 2, all the cells in column A were formatted with this conditional format.
With maintainance a boiler should last 15 years. A combo boiler is used more than any other boiler because of constant demand.A heat exchanger replacement you have to consider age and shape of unit.ith maintainance a boiler should last 15 years. A combo boiler is used more than any other boiler because of constant demand.
With a combi boiler, you'll save on hot water costs. (In fact, according to a 2005 Green Affordable Housing Coalition report, combination water and space heating systems can reduce utility costs by 15 percent or more compared to standard installation of separate furnace and water heater systems.).f fed directly from the main water supply to the heat exchanger, the combi boiler can have an unlimited hot water supply as long as the boiler is firing. Combis manage to extract a larger amount of heat from the flue gases that escape from the flue system, which increases the combi's efficiency.