As I have Time Now-a-days

[DaveA1]

I decided to have look to see if the heater pipe, under the floor, to the wash room was insulated. I think it is, but none of the measurements tally.
The OD of the heater pipe in the van is 65 mm as against the 72 mm spec. The OD of what looks like the pipe insulation under the van is 75 mm as against 85 mm spec. If these sizes are nominal they must be nominal plus.
Is this normal on 2012 Swifts. ???

 

[ProfJohnL]

Where did you get your information about the ducts fitted to your caravan?

The standard Truma internal duct has always been 65mmOD (UR ducting) and the Truma insulated duct had a 75mmOD.

It is possible the caravan manufacturer might have sourced their own ducting.

 

[DaveA1]

https://www.leisureshopdirect.com/g...lating-ducting-for-blown-air-system-2m-length
https://www.pipelagging.com/pipe-insulation/insulation-by-pipe-size/80mm-pipe-insulation

From a post by Otherclive posted some time back, after a search.

The sizes I quoted above, in the first post, I went to the van and measured the OD. Lot different. Which appears from what you say they are standard. The ones in the link above are different.