Morning all.
I’ve had a renault premium for a few months now and the other day decided to fire up the night heater to check all was well with winter on its way. Trouble is,all is not well.
So I turn it on via the switch by the handbrake, the fan kicks, the small fuel pump is ticking away,but the thing won’t fire up,its just bellowing pure white smoke out of the small under cab exhaust, tried it a good few times,with engine running and without but its just not having it. I’ve tried running it on differnet temperature settings too. Bit stumped really. Hopefully someone can offer some advice as our lot don’t touch night heaters so I have to get an outside man in who’s a nightmare to get hold of/meet up with.
Cheers in advance 
Take off the metal cover under the bunk behind drivers seat and make sure the night heater hasn’t sucked up an old sock or ■■■■■ etc. what age is it? Mines an 06 (old shape) and my night heater is very temperamental. When I fire mine up it doesn’t kick out hot air first time I have to turn mine on wait for it to get up to speed then turn it off until it’s stopped then it works fine. Last year it wouldn’t come on at all and after much head scratching I ended up taking out the wire that runs the diagnostics for the night heater. It works now! If any if that doesn’t work you have to throw holy water on it and prepare to do battle with evil spirits.
have you tried a box of Swan Vesta 
Don’t suffer the problem.
Remove the night heater and send it for a service. There will be a local dealer near you. You will then have a reliable heater for years. I used to mess about changing plugs and waiting for the smoke to disappear then it would kick in. I was thinking I cant afford a new one, when a small service does the trick. I learned my lesson at -16 degrees one night.
I think you’ll tend to find that wage glow plug wants replacing. It’s the only real problem I’ve ever known with them if they’re spinning up. Sometimes the fuel pump, but if it’s clicking, then it probably works. 15 minute job for someone who knows how to replace the glow plug.
I have posted all year to run the heater all year round to keep the gubbins and what nots moving.
Why wait until it gets cold to find out it is not working.
Check the battery voltage.Nothing worse than waking up in a cold cab.
Funnily enough mine in the premium is just blowing cold air and the light flashes after a while to let me know all is not well, has been running fine recently though, this was just after a service. Cold plums in the morning for a while…
If its a webasto its five minutes to change the glow plug,it even comes with its own little box spanner in the box.If its an erberspacher its remove the heater and a full strip of the heat exchanger and replace the plug and the thermal sensor.Pain in the arse job takes about 2 hours.
The first time it lets you down will be on the first cold night of the winter.
Sod’s Law. 
Run it all year to keep it going.Once a week in the summer.
Mine broke down while parked by a frozen lake in Saint Moritz Switzerland.
The ice formed inside the cab on the windows.
It was warmer outside the cab.
I fired up the engine and a rich lady told me off for making smoke and will damage the mountains.
Shame she didn’t invite you in for hot toddy and a BJ Toby. 