Probably needs a new battery assuming its the same as the one we had in a previous caravan. That bottom panel should be able to be removed to give you access? Have you the service book? If not a search online should bring up the instructions.
Same heater as on our van.
Bottom right hand corner behind the panel is a little black box containing a AA battery. I find it I lie down on the floor with a long screwdriver I can lift the slide flap, ease out the battery and with a bit of care get the new battery in and close the flap.
Bit fiddly but I find it easier than having to take the front cover off.
So we think the ignition box is dead - no life whatsoever after taking it out and testing it with a brand new battery so we're going to fit a piezo ignition which is far cheaper than the £100 that a new ignition box costs!!!
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