Propex underneath?

[Wychall]

Has anyone fitted a Propex underneath the 'bus instead of inside? My lpg tank takes up too much under seat space to be able to fit it internally so I am considering the space above the transaxle.

Also, what is the noise level of heaters such as these. My only experience of supplementary heaters are Ebers and Webs on the mini coaches that I drive and I wouldn't like to camp with roaring like they make!

[Ian Hulley]

When you are inside the camper you barely hear an Eber once it is up to temperature, Propex are even quieter so I'm lead to believe. Sorry can't comment on the whys and wherefores of mounting a Propex.

Ian

[1664]

There has been examples of Propexes mounted under vans but by being exposed to the elements they rot away (I don't think they're designed for exterior fitting). I suppose you could enclose them in something to protect them. Give Propex a bell?

[chriscburgess]

When i bought my Westy it had a propex fitted underneath but all the ducting had rotted away so i have never used it.

Did try to fire it up once but to no avail - so it is still there not doing very much

[BOXY]

My Propex was fitted underneath from "new" by Autohomes. The "lid" of the casing had completely rotted and I ended up bodging a new box for it using an old video recorder. There was the remains of a sticker that warned about external fitment, that funnily had managed to prevent the rust where it was stuck!

[1664]

Sure it wasn't retro fitted? Autohomes generally bunged them in the cupboard below the cooker - unless that was just the later conversions....

[BOXY]

Page 16 of the Autohomes "manual" that came with my van:-

4.1 Blown Air Heater
The heater unit is fitted outside the living area beneath the vehicle floor on the offside. The heater unit is ducted into the vehicle interior via ducting through the floor of the sink unit, with the outlet in the plinth under the cupboard door.

The unit hasn't got a thermostat, just an on-off switch on the front of the zig unit, so I guess this was an early install.

[garyd]

I visited the Caravan & Camping show today and by chance found some info directly relevant to this question.

It turns out that Whale (water pumps, etc) now manufacture all the Propex heater units and also make and develop their own brand units as well. Whale are particularly pushing the underfloor mount for use in caravans (built into the chassis spaces).

The main difference with the underfloor units is that they are heavily insulated (against heat loss) and mounted within a secondary casing.

Garyd

[call me Al]

I saw the same heaters and was told the under floor ones were not for retail sale, you can only buy the version that stands on edge

[captain Byrne]

I fitted my propex underneath - works fine. I cobbled together a protective cover made from tin plate. You can get sheets of tin from plumbers merchants or B&Q, ask for a blank closure plate, they should know what you're talking about.
Get some flexy steel tubing for the air inlet & exhaust and bend it around the side of the heater. This will prevent water entering the inlet when it rains.

[autostart]

I've got a autohomes camper and it had a propex underneath it from new,it had never been used, and it was rusty and didn't work,I think the changes in the weather got to it (wet,dry sunny,snow etc) got to it.my camper has only done 58.000 miles,so I fitted a new one inside, where the potty used to be,but I'm guessing if you have it on the outside you got to think that when it heats up an cools down will it suffer from condensation,leading to rust,as It's only thin metal and paint,and propex do tell you its not designed to go outside.hope that helps.

[silverbullet]

Has anyone fitted a Propex underneath the 'bus instead of inside? My lpg tank takes up too much under seat space to be able to fit it internally so I am considering the space above the transaxle.

Don't see why not, if it's up high i.e. fixed to the upper floor, it'll stay dry especially if a bit of strategically-placed rubber sheeting (neoprene) is used to close off the sides of the wheel arches (or splash* out on arch liners from Bricky)
Combine that with a generous tin splash guard from below, job's a good'un. Make sure it doesn't drub though...

* whoops, terrible pun

[Oldiebut goodie]

I find it strange that people will not mount heaters externally in a sealed box. I had trouble on another forum trying to persuade someone that they could mount their Eberspacher externally even after copying the relevant paragraphs in Eberspacher's installation instructions. Eberspacher even have the boxes in their parts catalogue! I would just ensure that there was insulated ducting to the interior for the air inlet and outlets to cut down on heat losses. A lot of lorries have theirs mounted externally in enclosures.
When space is at a premium internally it is the obvious solution. Admittedly there is more work involved due to having to cut another hole in the floor.

[autostart]

I can see your points,but if you was to go the whole hog like the lorrys have,it would be best to have a box welded to the underside and a purpose made hatch for servicing of the heater,but then how much money do you have for your van?I use mine as a daily driver

[Oldiebut goodie]

No hatch required - if it were you would mount it internally as it would occupy the same space! They have a drop down side door. They are bolted on - no welding required.