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.
Replacing an existing gas condensing combi boiler in the same position as the previous one. This job involves removing and disposing of the old boiler before installing the new one. Expect to pay Around Â£540 - Â£660. If your heating system is very old, it may need a mechanical flush - which costs around Â£510.