We've had a new Keston 28s fitted with megaflow in our basement. Pipes come up through kitchen and vent outside back door. When boiler is on there's very loud gurgling from the flue (there are 2 pipes outside). If I put heating on, there's the gurgle AND slooshing sound from the boxed in pipes in the kitchen. Installer has ensured pipes are at right angle to vent out, have had a good look at the boiler and nothing has helped. The installers are doing their best but I sense they just don't know the answer so if anyone has any ideas or has had this before, be great to hear the solution. It's so bad that we feel obliged to turn the boiler off whenever we can to save our neighbours the misery! Thanks