Club 80-90 Forums

Hi all, installed a propex compact 1600 a couple of years ago but haven't had cause to use it all night ie cold winter camping. Have run it up up on numerous occasions for a few minutes to keep it serviceable. But recently testing on longer runs have noticed it doesn't cut out even on a low heat setting running for 30 mins or more, is it a wiring problem or faulty thermostat, thanks in advance for replies.

Adjust the thermistor behind black box cover. This is from club 8090 wiki

Adjusting Sensitivity
If you're finding that even after setting desired temperature for your Propex, it starts to get chilly and the heater still hasn't kicked in as soon as you'd like and you're constantly having to nudge or adjust the thermostat dial, the sensitivity may need adjustment. There is a small preset adjuster on the thermostat circuit board. This adjuster is a hysteresis control which can alter the temperature differential from as wide as 4°C to as little as 1/2°C.

To gain acces to it, first pull the dial knob off and remove case by undoing the screw beneath the knob.

If you look carefully at the board you should see a small white or blue round component, into which you can insert a tiny screwdriver and turn to adjust. Note its present position for reference. There is a small arrow in the centre to show which way it is adjusted.

For maximum sensitivity turn the preset fully anticlockwise, and for minimum sensitivity turn it clockwise. The preset is not a linear control and most of the adjustment is actually toward the anticlockwise endstop.

IMPORTANT: You don't want it so sensitive that the heater cuts in and out too regularly as it will be less economic to run then. Trial and error may be needed to get it just right. Once you've got it right - leave well alone!


If this doesnt work speak to Propex. They are very approachable.

Great stuff maxstu, will give it a go, sounds as though thats the problem.

Is this possible with the newer hs2000 propex thermostat? I assume not as I cant see any screw component in mine

Insulation helps keep in the heat a bit longer so the cut in/out is further apart.
It's a shame propex doesn't have a lower cycle like fluid heaters do.
I would imagine it's not as easy as it sounds.
The gas flow would need slowing and the blower speed lowering.

When my Propex thermostat died (many years ago now) I looked at the wiring and realised it was so simple I could use any old thermostat I wanted. I ended up with a compact Sunvic surface mount programmable unit (model TLX6501 from B&Q iirc) which runs for years off two AA cells, and has been really superb. The timer function is really useful.

Thanks for all your replies, needed new thermostat, up and running now.