Propex Heater

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To 937 carrera
Sending you some photos

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Here's the next three.

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And the next 3

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And the last 3

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Sorry 937 carrera. I forgot to send you the control box picture

[937carrera]

Great, you have got the hang of attaching photos

So, a few initial thoughts,

This looks like an earlier model of 1600 than I have seen before, not that it makes a lot of difference.
The control unit is also simpler, just on / off
There are some diagnostics available.

This is what I suggest you do (maybe a repeat)

- Reconnect everything, including gas supply, if you don't have gas, you will need to get some soon.
- Make sure the main battery (and leisure battery if you have one) have a decent charge and any switches to make them live are switched on - minimum 12.4v checked with a meter (if you don't have one can you borrow one, if you can't borrow one you can get them on ebay / amazon for about a tenner)
- Turn the thermostat onto 7
- Switch the unit on

Watch the red light on the thermostat, does it glow red or flash at all.
Watch the diagnostic lights on the top of the unit, do any of them light up.

From what you said before I suspect nothing will happen.

If as I suspect nothing happens then we next need to make sure that the heater is getting 12v.

First thing is to simply test for 12v at the heater box, probably at the connector block you pictured, but before that make sure the fuse hasn't blown and is not corroded.

I have just seen the latest photo, that's a Lab-Craft CP4 distribution unit and there's a wiring diagram in this thread http://forum.club8090.co.uk/viewtopic.php?p=8203150 which would seem to indicate that fuse 4 is the one that feeds the unit. Another member on here had a similar problem and it was just a corroded fuse / fuse fitting. A quick clean with abrasive paper and a bit of contact spray had that solved.

Does the water level work when you press the button, do any of the the battery light illuminate, engine off or running

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to 937 carrera
Thanks for your comprehensive reply and so soon !
The weather's pretty lousy down here in Brighton so I probably won't be going out to the van for the time being. (I've also got tons of other stuff to attend to at the moment). However, I can say a couple of things. 1) I checked through the fuses on the Labcraft unit last summer and the propex heater one seemed to be fine. Also, the light comes on on the thermostat albeit a bit fainter than it should be so electricity is definitely coming through 2) the water gauge probably doesn't work because I've drained all the water out of the tank (there was a tiny water leak which was going into the sill just above the rear suspension mounting and as we didn't use the tank water at all I simply drained it out) 3) Last summer I got to grips with the leisure battery charging system and also the fridge wiring. I disconnected the gas burner supply to the fridge altogether because it was too rusty to be saved and then I discovered that the fridge would only operate electrically if the ignition was on - just like the propex heater thermostat ! - so I ran an extension lead from the socket on the labcraft unit direct to the fridge (and modified the fridge connections somewhat). That way we can keep the fridge running on the leisure battery when the vehicle is stationary. I hope my modifications won't sabotage the propex heater circuit. Don't think they will.

[937carrera]

OK, come back when the weather is better and you've had chance to check things out.

A dimly glowing light indicates a bad feed or earth, or a low battery

Fridges are only supposed to operate electrically when the engine is running or on 240v. The current draw is too big to be run off the leisure battery, it'll flatten it in no time (80 ah battery, ~8A for the fridge, leave it running overnight and the battery is flat and possibly damaged)

I would expect the water meter needle to move even with no water in.

[steveo9007]

OK, come back when the weather is better and you've had chance to check things out.

A dimly glowing light indicates a bad feed or earth, or a low battery

Fridges are only supposed to operate electrically when the engine is running or on 240v. The current draw is too big to be run off the leisure battery, it'll flatten it in no time (80 ah battery, ~8A for the fridge, leave it running overnight and the battery is flat and possibly damaged)

I would expect the water meter needle to move even with no water in.

As 937 mentioned, your water meter should move slightly even with no water in and button pressed as its electrical connected up in the W1 and W2 connections on the back of this control unit, i have just wired up this unit to my campervan, but i don't have a propex heater fitted but in the wiring diagram i followed and got my head around it, it connects to bottom right hand set of the 4 fuses and runs to the thermostat first and then to the Heater box



And i second the fridge running on battery, only with engine running and plus you will not have no control over the coolness as it won't go through the temp dial that's only for 240volt operation, so when running on batteries with engine running it should be enough to cool down fridge till you get to where you need to and then switch over to hook-up as soon as practically possible.

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Thanks 937 carrera and steveo9007. Very grateful for all assistance so far. Will come back when I have a bit more time to devote to the wiring etc.

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to 937 carrera
I have resurrected my ancient Altai Multitester (it's analogue but it works, plus I have a 12 volt continuity tester at my disposal together with some lengths of wire with crocodile clips) and from tomorrow (Wed 25th June) I will have time to have a look at the wiring. Hope you're still able to advise me how to go about it. Sorry it's been such a long time lapse. I had a number of household emergencies to deal with. Rgds.

[937carrera]

still here......... with a bunch of others who can help too

[steveo9007]

still here......... with a bunch of others who can help too

Not good with propex heater but happy with electrics and the panel you have as mine is up and running all good with water tested and 12v running fridge when engine running confirmed at the weekend on a run to a campsite.

[t3convert]

to 937 carrera,
Have tested cable entering propex heater with multimeter and there is no current whatsoever showing despite thermostat being switched on (light showing red) and all fuses on Labcraft C4 unit intact except water pump 7.5 amp, which I stole to replace previously blown fuse 2 because I no longer need the water pump. The water level indicator doesn't respond either. I previously told you that the ignition needed to be on for the thermostat to work but I had forgotten to connect up the leisure battery and now it comes on without the ignition. Photo (hopefully) of strip connector at the heater end where I failed to detect current.

[937carrera]

The proper heater will not work without power, so you need to read the circuit diagram Steve9007 provided and work your way through.

So, follow the circuit, leisure battery > fuse > 10A connector block > fuse > thermostat > heater.

You need to see if you can get 12v at each of those points. I would start at the fuse first, if there's 12v to earth there, work forwards to the thermostat, if not, work backwards to the battery.

Do those tests and report back

Have you traced where the cables in that connector block go - I'm not sure they are actually part of the propex circuit