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.
Heating, Ventilation, and Air Conditioning (HVAC). Heating, ventilation, and air conditioning systems require proper and regular maintenance in order to work efficiently, but even in the best case scenarios most components of such systems only last 15 to 25 years.Furnaces on average last 15-20 years, heat pumps 16 years, and air conditioning units 10-15 years.Tankless water heaters last more than 20 years, while an electric or gas water heater has a life expectancy of about 10 years.eating, Ventilation, and Air Conditioning (HVAC). Heating, ventilation, and air conditioning systems require proper and regular maintenance in order to work efficiently, but even in the best case scenarios most components of such systems only last 15 to 25 years.