My truma gas fire won’t light, light. It try’s & seemed to splutter a tiny amount. I wonder if it could be a thermo coupler thing. Any one had problems before?

Usually the problem is the thing won't actually light, but if it's sputtered into life it shows that the igniter is working and gas is getting through. You do need to hold the knob down, once lit to allow the flame to warm the thermocouple, which, in turn will release the gas valve, at which point you can let go and the gas valve will open for a full fire. So logically either the knob hasn't been held down long enough, the pilot light type valve has become a home to spiders, the thermocouple is bust, or the gas valve aussi. Without a qualified gas engineer it's difficult to know which of those it might be. Though you can try holding the knob down longer, if you haven't already and you've probably toasted the spiders with the initial spluttering.

We’ve had it on over the weekend working perfectly till this morning when I could only get the pilot light lit briefly & then when you turn the knob to light the main burner it splutters ever so slightly trying to light & goes out. I think it’s going to be the therm couple, caravan is under warranty but an hr or so to dealer, leave it with them, home & go back another day

The fault symptoms you describe suggest you're either just about to run out of gas or you have a faulty regulator.

Ours won't light at all. The van is new to us and everything else works. I'll keep an eye on this thread in case we learn anything useful with thanks. We have gas that works on all other appliances. We have a spark. We've tried holding down for a long time to pull the gas through. Ours is trumatic (if you'll pardon the pun).

If you have a spark and no flame, then you have no gas.

If the gas hobs light then they have gas, which means the cylinder is turned on and the regulator is regulating plus the hob isolation valve is turned on. So if the hobs work check that the heater's isolation valve is also turned to the on position.

Changed cylinder & still the same + hob burns ok and we had been using over weekend

Just going to say, change cylinder as we find the fridge and heating don't like nearly empty bottles. Maybe an air lock in heating system? Are you holding the knob in for ten seconds or so, and release very slowly.

Ah!, so you have been using the heater recently?

Presumably there's no smell of gas, so no leak?

Can you hear a faint hiss when you turn the heater on and press the igniter?

Are you certain that the isolation valve hasn't been turned to the off position?

The gas pressure, especially from a new cylinder, on a pipe run where the heater has been used recently shouldn't have an airlock.

Well this is very strange, I’m home now & just retried it & it works!! I’m grasping at straws, it was quite windy where we were& the other thing if this has any bearing on things. I’ve never known or had the extension flue to screw on. I gather there supposed to help keep fumes away from pop top, wouldn’t have thought it would have effected the lighting. I’d spoken to the main dealer I bought it off and they were supposed to drop me a flue off

The flue could make a substantial difference.

Somebody on an Autosleeper forum was having problems keeping his Truma heater alight in windy weather with the one chimney extension fitted. He purchased a second, which protruded slightly over the upright panels on either side of his van roof and the fire stayed alight with no issue. I suspect the extra height increases the draw of the chimney as well as reducing wind turbulence down it. I don't suggest you purchase a second as the original equipment one should be sufficient and I also suspect that wind direction and local positioning effects mean that normally all would be fine.

just come off the phone from the dealers (workshop Forman) and describing the fault of not lighting from the piolet light & he said they have come across this problem before when it's be windy & its been the wind under the floor under the heater & mentioned someone had carefully made some sort of shroud. when I'm home tonight i must take a look but i imagine one would have to be very carefully done if at all !!

Caravans all have holes in the floor, especially under any gas fired appliance. They're gas drop-out vents. They're there to allow the propane/butane gases, which are heavier than air, to drop-out of the van, in the event of a gas leak. Anything that blocks such a vent, or extends it upwards to try and prevent draughts, risks gas pooling at the lowest point in the van, waiting for a spark to set off an explosion.

Don’t worry I wouldn’t dream of blocking any vents. I’ve rung Truma Uk on the subject after seeing quite a few posts on the subject and no doubt some will need countless different remedies including a gas engineer. But what I’m trying to find out is first is it wind blowing under the caravan & if so what do Truma say. I have heard of people ( I’m not necessarily endorsing this) making something like a biscuit tin with no bottom to extend downwards totally open so gas can sink but to create a wind protection. Like a said I’ve spoken to Truma and waiting for them to come back to me but mean while I will monitor my fire to try to get to the bottom which might take some time if I’m not out in similar windy conditions