Propex Heater

The Tardis factor (interiors, awnings, roofs etc)

Moderators: User administrators, Moderators

User avatar
steveo9007
Trader
Posts: 319
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: Propex Heater

Post by steveo9007 »

I did find this wiring diagram, not sure if it would also assist

Image
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

t3convert
Registered user
Posts: 53
Joined: 03 Nov 2017, 18:53
80-90 Mem No: 16325
Location: Brighton E.Sussex

Re: Propex Heater

Post by t3convert »

to 937carrera, Steve9007 and Oldie but Goodie
Many thanks for all your combined input.
I'm going to have to research a bit more as to where the defunct wires have been buried before finally inserting new ones.
It looks as if I'll need to connect it all up and be prepared to swap terminal 2 and 3 wires over if they're the wrong way round.
However, I'm wary of turning on the gas and starting the Propex up just at the moment because there seems to be a leaky petrol seal or two coming from the fuel expansion tanks under the front wheel arches. If I fill the tank up until the automatic stops there is a strong smell of petrol and any spark from the Propex ignition could possibly incinerate the van. So it looks like there's going to be another pause until I've sorted out where the leak/leaks are coming from. I'll get back to you when I feel it's safe to switch the Propex on

t3convert
Registered user
Posts: 53
Joined: 03 Nov 2017, 18:53
80-90 Mem No: 16325
Location: Brighton E.Sussex

Re: Propex Heater

Post by t3convert »

to 937carrera and Steveo9007
I had a look under the wheel arches and there are no tell-tale signs of a petrol leak. The fumes only occur if I fill the tank up full and disappear after I've done a few miles so it should be something to do with the breather/expansion pipes. I'll have to have another check when I next fill up with petrol. In the meantime I'm going to make a test rig for the Propex Heater inside the van but well away from any potential fumes. But before I do so I need to re-think the way I was going to run the wires from the thermostat. Steveo9007's basic wiring diagram makes me think I've got it all wrong.

User avatar
937carrera
Registered user
Posts: 3599
Joined: 05 Apr 2015, 19:29
80-90 Mem No: 16333
Location: N Yorks.

Re: Propex Heater

Post by 937carrera »

A bit more investigation

https://www.volkszone.com/VZi/showthread.php?t=430804

http://thelatebay.com/index.php?threads ... pex.16013/

Based on this

Red - Battery +ve
Black - Battery -ve
Purple - Trigger for fan on heater, needs this to run on and cool down too
Orange - Thermostat connection to heater, open, burner off, closed switch, burner on

While the coloured diagram is easier to read I note that it doesn't have the earth /-ve route that the Propex manual says is required.

So I think we are in the same position. Remove the thermostat, find the existing wiring and connect up all 4 wires and splice in the Black / red supply cable.

If the existing wiring does not have the "4 core cable", then you need to source some. Trailer cable has 7 wires in it, it is readily available so get some and use 4 of those, they will be well over specified for this application. You can re-use the existing power supply cable.

Looking at the photo of your thermostat wiring it does not look like the proper wiring is there, simply because I can see two red wires and two black wires. It is possible these are extensions of the original wiring which may have been too short if the installation is of a s/h unit from another vehicle, but who knows. You will need to trace and isolate / remove that redundant wiring in the end anyway.

I had the usual problem with the leaks from the breather...... until you get it sorted don't fill the tank, keep it below 3/4 and you'll get better MPG as you stop tipping it out onto the road on corners :wink:
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

User avatar
Oldiebut goodie
Registered user
Posts: 7260
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: Propex Heater

Post by Oldiebut goodie »

Propex say somewhere that the 1600 doesn't utilize the cool down feature apparently - this came in with the later models. I think that you are chasing your own tails trying to use those unconnected wires!
Basics first.
Open the box! Is the fan free to move? They are known to seize due to lack of use every month. Nothing will happen if the unit senses a seized motor for safety reasons.
I think that the wiring at the thermostat is correct as it is - you only need to apply power to the heater nothing else. Old Webastos ran the same thermostat wiring, heater either on or off nothing else. (Just because there are unused wires in a loom it doesn't necessarily mean that they have to be used - Webastos can have up to 6 unused wires in a loom that are not used in a standard configuration!)

Don't overthink what is there.

( Ignore Steveo9007's pics etc. as they are for a 1600 Compact which isn't the model that you have as with the thermostat)
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

User avatar
937carrera
Registered user
Posts: 3599
Joined: 05 Apr 2015, 19:29
80-90 Mem No: 16333
Location: N Yorks.

Re: Propex Heater

Post by 937carrera »

This is the oldest Propex manual we have been able to find - version 2, I know there is a version 5 out there

https://www.propexheatsource.co.uk/wp-c ... ions_2.pdf

The wiring from the heater itself does have 4 wires, two are tucked away and not used as you can see in this photo

strip connector2.jpg
strip connector2.jpg (16.25 KiB) Viewed 3466 times

We're not at the point of needing to check the safety device yet. The ventilation fan will run without a problem, regardless of how long the unit has been left, the bit that sticks is the little unpowered "fan" that rotates because of the airflow from the ventilation fan. If that is stuck solid then the gas burner will not fire up.

Based on electrical tests the thermostat unit is live, and if I recall correctly the connector block shown is not.

We have no idea what a previous owner has done, it seems seriously deficient, so in this case I think it's best to rip the old wiring out and start again

Only the OP can decide what they are comfortable doing and the route to take.
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

User avatar
937carrera
Registered user
Posts: 3599
Joined: 05 Apr 2015, 19:29
80-90 Mem No: 16333
Location: N Yorks.

Re: Propex Heater

Post by 937carrera »

OBG,

I just picked up on your point about the 1600W vs 1600 compact models, so have been searching some more

I have a HS2000 in the truck, a 1600 compact in my Autosleeper and an earlier 1600 in my CU, but am not close to any of them to check at the moment.

Instructions for the 1600W and 2600W

http://www.holdsworth.vwt4camper.info/1 ... nsT4WM.pdf

I saw a download which indicated that the instructions for the 1600W and the X1 model are the same, Propex still have the X1 instructions available

https://www.propexheatsource.co.uk/x1_instructions

Now all of those have the 4 wires, and then I found this which only has three

http://forum.club8090.co.uk/viewtopic.php?f=39&t=159278

Which talks about wiring for devices with and without purge

Look carefully at the thermostat though, the one the OP has is different to the one in the other thread, so is this one with the purge ??

Are the internals on this early model also different so that it is the movement of the ventilation fan which allows the burner to fire up, pre-dating the design with the secondary monitoring "fan"
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

t3convert
Registered user
Posts: 53
Joined: 03 Nov 2017, 18:53
80-90 Mem No: 16325
Location: Brighton E.Sussex

Re: Propex Heater

Post by t3convert »

This is the diagram from inside the lid of the thermostat
Attachments
023.jpg
023.jpg (52.85 KiB) Viewed 3461 times

User avatar
937carrera
Registered user
Posts: 3599
Joined: 05 Apr 2015, 19:29
80-90 Mem No: 16333
Location: N Yorks.

Re: Propex Heater

Post by 937carrera »

Ahhh, well that's useful :)

I think that confirms it is an early 3 wire version, reference the 80-90 link http://forum.club8090.co.uk/viewtopic.php?f=39&t=159278

Terminal 1 - Battery +ve
Terminal 2 - Red and orange wire to the heater, this becomes live when the thermostat is switched on (I don't see why the orange wire is even needed)
Terminal 3 (or 2a) -
Terminal 4 - Battery -ve and heater -ve, black wires

Now all you have to do is make sure the wires are connected correctly at the thermostat and the two connections (3 wires) at the terminal block.

If I remember correctly the thermostat was live, but the terminal block was still dead.

Check for 12v at terminal 2 and at the red connection on the terminal block. If it is still 0v at the terminal block, turn the thermostat off and do a continuity check between terminal 2 and the red wire at the terminal block
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

User avatar
Oldiebut goodie
Registered user
Posts: 7260
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: Propex Heater

Post by Oldiebut goodie »

Oldiebut goodie wrote:Not necessarily - wiring diagram is usually inside the top. Orange is likely to be switch on of heater and blue switch on of ventilation. Not normally signal wires on a crude thermostat like that just power. If they were signal you wouldn't need the relay on the board.
Oldiebut goodie wrote:t3converts pic shows normal connection for heating with no ventilation provision - I hazard a guess that the switch on his is purely an on/off switch.

E D I T: have gone back to his earlier posts - his IS purely on/off.
:idea
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

User avatar
Oldiebut goodie
Registered user
Posts: 7260
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: Propex Heater

Post by Oldiebut goodie »

Power cut for the last 3.5 hours - just hooked up inverter to check emails. Power back around 24.00 if we are lucky so will be offline for some time.
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

t3convert
Registered user
Posts: 53
Joined: 03 Nov 2017, 18:53
80-90 Mem No: 16325
Location: Brighton E.Sussex

Re: Propex Heater

Post by t3convert »

I took the thermostat off and photographed it at an angle so that you can see the labelling on the terminals.
Attachments
024.jpg
024.jpg (66.82 KiB) Viewed 3449 times

t3convert
Registered user
Posts: 53
Joined: 03 Nov 2017, 18:53
80-90 Mem No: 16325
Location: Brighton E.Sussex

Re: Propex Heater

Post by t3convert »

to 937carrera and Steve2007
Sorry, the last photo was of the back of the thermostat and showed the labelling.
This last one is of the side (I think)
Attachments
025.jpg
025.jpg (77.91 KiB) Viewed 3450 times

User avatar
937carrera
Registered user
Posts: 3599
Joined: 05 Apr 2015, 19:29
80-90 Mem No: 16333
Location: N Yorks.

Re: Propex Heater

Post by 937carrera »

That confirms the required wiring then, check the wiring runs and connect it all back up and test in line with my post at 17:55 last night.

BY the way, reading between the lines, I think OBG used to be involved in installing / repairing vehicle heating systems in some form so his comments are particularly valuable, he is the one that knew that the early 1600W had different wiring to the later models and the 1600 compact.

Through this thread I now know the wiring diagrams are contained in the thermostat, something for me to remember :)

I hope OBG has power again this morning, I'm not sure if firing up the inverter means he's on a camp site and mains there has gone down, or his main power at home has gone down so he's just fired up an inverter generator to power his house like many in the US do (they have many more outages than us)
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

t3convert
Registered user
Posts: 53
Joined: 03 Nov 2017, 18:53
80-90 Mem No: 16325
Location: Brighton E.Sussex

Re: Propex Heater

Post by t3convert »

to 937 carrera, Steve9007 and OBG
I've made a bit of progress.
With the thermostat turned off I continuity checked from the leisure battery to the terminal block at the heater end via terminal 2 on the thermostat and the red wire showed 12v, similarly the black wire via terminal 4. So I can leave the wiring in the thermostat in place as OBG suggested and I don't have to run any fresh wires from the thermostat to the terminal block at the heater. That is good news indeed.

Post Reply