Moving oil boiler

`Why not butt it up against the wall of the house?

Insulation only works if it kept dry. I've seen loads of Insulation on those pipes and just thrown straight into the ground. I've also seen good jobs where sewer pipe was used to cover the Insulation, but it must be kept sealed from water ingress.

Dimentions for the Grant above. It's very neat and the one that I recommend first.

You can get a plume kit to take gasses away from windows, doors, vents etc. Bear in mind that you'll need to pipe the condensate away properly too.

The ones that I mostly saw done were done with that dark grey pipe foam insulation that comes in about 1 metre lengths. (Sometimes more than one layer of it and 6" pipe used) This is also the way I've done some of them myself. They are then inserted into the 4 or 6" wavin and any joints sealed with the proper joiner and sealing rubber rings. The a bend (mostly 45°) and a little extra pipe if needed to come out of the trench into a water proofed area such as the boiler house and hot-press. This is even easier to do nowadays with the introduction of flexible pipes, though those cannot be used close to the boiler and a short length of copper is needed there.