Webasto Heater install advice

[puddin]

Good afternoon all.

I have an old Webasto HL18b (Petrol) heater that I picked up last year. I'm after some advice and wisdom before fitting it to my Westy.

First things first.....
Is it really wise to fit an old heater? TBH, aside from CO poisoning, I really don't understand what other risks come with fitting an older unit. I have no service history for it but it's clean and appears to be in good condition and functions well.

Where to fit it?
I'd prefer to mount it externally as I like to retain the space under the seat, also fitting under the rear seat looks tricky due to the previous heater cutouts and seat base panel.
External mounting boxes on FleaBay appear to need modification to fit where the original Eber box would sit.
Any suggestions on what boxes fit well?

Can I mount the heater on it's side?
So that the Exhaust and Inlets are 90 degrees from vertical. This seems to be how newer heaters are typically mounted in boxes. Unfortunately the manual I've found offers no guidance on mounting positions.

Any advice gratefully received.
Cheers

[Oldiebut goodie]

No risk of CO poisoning unless you vent the exhaust into the interior!

Don't fit it until you have replaced the burner pads, the neoprene seal to the heater body for the wiring connector and the one at the base. Check that the silicone rubber seal for the exhaust at the base is in good, unsplit, condition, also the o-ring in the carrier. Check that the gasket at the base of the burner tube is good and not brittle - if not replace. Depending upon the age/model there may be an o-ring between the two parts there that will need checking also.
You can mount it on its side (page 12 of the installation manual gives permissible mounting angles) but you will not find a small box to suit off the shelf, you will have to fabricate one yourself. Under the rear seat is still the best position though - you can always put a shelf over it if you are that desperate for space (you will lose almost that amount of space anyway for the ducting to come through from underneath) Don't forget that you will need access to it in the future for maintenance.
You are extremely unlikely to be able to source new burner pads in Europe - you will have to contact me as I make my own to suit these heaters. Other spares are thin on the ground in the UK, can sometimes be found on German ebay. The only other thing that may need replacing on a heater that has had a lot of use are the brushes on the motor.

[puddin]

Thanks for the reply - much appreciated.

I'll check those items out and give you a shout for any bits.

Cheers
Tony