First things first, you must get a survey completed at gasway, we’ll do this for you for free some other companies charge over £100 to survey your house! we think this is a bit of rip-off so we don’t charge for it once you request a date we’ll then confirm the installation and answer any questions you might have concerning your new boiler and its specification. Jeffrey - chiswick - may-2017. Know your enemy, flush ’em away. Wall.