Swale Heating recently supplied a replacement boiler for us. However the vent on the new boiler is both much smaller and exits higher up through the wall than the previous vent. Swale Heating were supposed to brick up the hole in the external wall left over after the old vent was removed and use breeze blocks and plaster to repair the whole in the internal wall. However their engineer appears to have made a decision to take a shortcut and simply fit the boiler over the large hole in the internal wall. Since finding this out I have looked at reviews of Swale Heating and discovered that this is not the first time they have done this. If you have had a boiler fitted by Swale Heating to an external wall try looking behind it to see if they have done the job properly. I cannot see how the job they have done for us meets Building Regulations.