Hi all I have been quoted 2400 to rip out old boiler, immersion and the tanks in the loft and replace with a Worcester Bosch combi boiler which will be relocated in cupboard upstairs with flue through the roof, new gas pipe, mag cleaner, wireless thermostat, and a over flow pipe which will run outside, 1st does this sound a fair price and 2nd should all boiler changes require a power flush as he said no need as at some point I will be removing/changing most rads in the house? Thanks