The flint for the gas fire in my camping car is broken - any ideas on repairs?

It sounds like a piezoelectric ignitor like those on a gas grill. (Not a flint.)
Does it look like this?
You might be able to save it. Might!

The units are glued shut and are supposedly not able to come apart. But… if you have a vise you can grab the outer black ring with channel locks and while holding the lower part in the vise and twist it hard. The whole thing will come apart when the glue breaks. Cloean it and reglue with epoxy.

Or…if you have carb cleaner and compressed air you can spray some of that all around and inside the button and follow up with the compressed air. DO NOT CLICK IT WHILE IT IS WET!!! It can blow up in your hand if it ignites.

If this were my camping car I would replace it with a gas grill ignitor from Lowe’s or pay an extra $20 and get an electric start unit. They are great.

Remember, if you spray it with carb cleaner DO NOT CLICK IT WHILE IT IS WET!!!! GET IT?!?!? CAR.

That is really helpful. What is inside if I manage to open it ? what makes the current ? if that is what happens – I am a real amateur here !

If I get an electric start unit will it attach to the existing wire that goes to the pilot?

Just to get you by for now, you could also go to a store that sells “quincaillerie” or “produits de menage” and buy one of those clicking lighters (like this). It contains the same kind of spark generator. If you take it apart, you can remove the generator with its wires, then connect those wires to the wires that lead to your broken switch. This will now create the current needed for the spark in your heater.

Oh brilliant ! I have just found a video that shows how to do that, I will give it a go tomorrow :) Thank you for your response, I really appreciate the help both of you

Good luck!

Until you get it fixed or replaced, can you use a match or a grill lighter? I know I can with my camp stove, but it is an older model and some of the newer models are idiot proofed so they can only be started with the igniter.

You asked what is inside. It’s pure genius. The key to the operation is the piezoceramic slug mounted inside a hammer and anvil arrangement. “What the heck is piezoceramic?” you might ask? It is a ceramic slug about 6mm (¼ inch) in diameter and about 12 mm (½ inch) long. It is a ceramic with a special property: it takes mechanical energy and converts it directly to electrical energy at a pretty high efficiency (pushing 80%!). You smack it and it puts out up to 50,000 volts.
Piezoceramics are all over the place. Even today you used them. The watch beeper, your iPhone speaker, the vibration feature in your phone, the autofocus mechanism in the camera, alarms systems, many military, industrial, medical uses.
So how does it work? You push the red button and that pushes the hammer against a spring that is mostly axial but sideloaded by a few percent. There is a conical area near the bottom of the stroke that centers the hammer and “Whack!” it flies against the slug making the voltage spike. If you have an automatic center punch in your tool box you can unscrew it and see how it works. It is the same basic mechanism. .
The most common failure mode is the mechanical action: the hammer is not sideloaded enough so the spring does not catch or it has too much junk inside and the hammer is always centered. Try cleaning it with carb cleaner and air pressure.
Piezoceramics are fantastic feats of engineering. I love them.

Piezoceramics work by either mechanical energy in, electrical energy out, or vice versa. The former is used in your igniter, the latter for speakers etc.

@RocketGuy is correct. i should have stated most piezoceramics work in both directions: mechanical energy in, electrical energy out, and electrical in and mechanical out. Use the former when you want a quick source of electrical energy or want sensors that can harvest energy from vibration. Use the latter to make mechanical movement as in speakers, positioners, stepper motors, etc.
Wonderful stuff.

I am so grateful for your thorough responses. I have managed to sound as though I know what I am talking about at the hardware shop. One assistant brushed me off and the next one was dazzled by my grasp of the subject and consequently went to great lengths to make up a suitable spare part. Really appreciate the help. I am now warm and cozy.

Thanks for the update!

@Alisonprideaux Great! Did you go for the push button gas grill type or upgrade to the electric unit?
Try to clean/fix the old unit and keep it as a spare. The piezoceramic inside will still be good 10’s of thousands of years from now. Some archaeologist will find it and think mankind was so clever “way back then”.
(Not unlike how we marvel at the ancient south sea islanders who carried fire pistons like we carry Zippos.)