RECENTLY, I TOOK out the old Morco water heater to replace it with a Carver Cascade. Cascades fit through the wall into the caravan. Making an error cutting a hole in the wall can be a disaster, so I took extra care.
I thought the heater would go under the seat on an 18mm batten, but in that position the heater flange fouled the rubbing strake along the caravan’s bottom. Placing the heater too high fouled the trim covering a wall panel join. To achieve just the right height, I made a cutting template.
Having measured the heater, I drew a template of the opening on a piece of card. It’s easier to cut slightly undersize and then gradually remove sufficient material until the hole is just right rather than cut too much out and then have to try to fill in the hole, so I made the template slightly smaller than needed.
Having cut out the centre of the template, I had to trim the perimeter section until it fitted over the heater, confirming that the centre section was slightly undersize.
I used the template’s centre section to mark the hole’s position, avoiding the rubbing strake and upper trim. I masked the edge to stop the jigsaw’s sole plate damaging the paint, then drilled a 10mm hole in each corner and cut the central opening with the jigsaw.
Remember, I’d deliberately cut the hole undersize, so now I had to use my powerfile to open it up gradually until the heater could pass through it into the caravan.
The Morco’s flue had been screwed to a piece of 25mm plywood. I removed most of this with the jigsaw and fitted a timber frame round the edge to take the Cascade’s screws. Sikaflex 512 adhesive/sealant secured the frame between the aluminium and the wallboard.
I removed the old mastic and cleaned the flange with white spirit. Then I ran non-setting bedding mastic around the flange and fitted the heater in place. Because it was higher than originally intended, I temporarily supported the heater’s rear on a block of wood.
I drilled a hole through the aluminium for each screw and then secured the heater by fitting the screws in a diametrically opposite order so it was pulled against the aluminium evenly. I then used a plastic spatula and white spirit to clean off the excess mastic.
The final job was to fit the flue cover. The temporary block supporting the heater is still there. I won’t connect the gas pipe, mains and 12V cables until I’ve also fitted a new space heater and fridge. Then I’ll put the caravan on the lift so I can work underneath it.