How can you change the lightbulb for the flames when it burns out on a wall-mounted electric fireplace-heater?

I assume the fire still heats up (but the lamp does not illuminate) when it is switched on. If not, check the fuses in the plug and the “consumer unit” (the main fuse box usually adjacent to the electric meter). If you have no way of “checking them” with a measuring instrument then swap the suspect fuse with a known-good replacement.

Still no luck? OK - to be honest I don’t actually KNOW how to do this (because I am not familiar with this particular “fire”), but I deal with these sort of problems all the time, and they can almost always be solved without any specialist knowledge.

We just need to apply our intelligence into deducing how it might (or more likely MUST) be done.

This is how to think out the solution:

How was the fire installed?

Ans: No obvious externally visible fixings, so the concealed internal grate assembly (holding the electrics, lamp and “coals”) was somehow initially pushed into the recess. It may be self-supporting inside the recess, or it may be securely attached to the visible, external metallic rim.

In either case, the external metallic rim must be secured against the surface of the wall - so the rim was probably manoeuvred, flush to the wall, slightly above some (probably four) hook-like fixtures that had already been securely attached to the wall.

The outer rim, possibly (but not necessarily) together with the internal fire assembly, would then have been allowed to slide down onto the supporting hooks.

The smoked glass front-panel must also be attached onto the metallic rim. This panel could be permanently attached to the metallic rim, or (alternatively) must be capable of being installed (and therefore also removed) after the main fire assembly has been inserted into the recess in the wall, along with the metallic rim.

Conclusion:

First TURN OFF the electrical supply to the fire and, if it is still hot, let it cool down.

Then: try lifting the smoked glass panel, vertically upwards, to see if it can be detached from the metallic rim. Also, try moving the glass panel, left and right (horizontally), as well as, subsequently twisting it a little (anticlockwise then clockwise) to see if it can be loosened from any supporting hooks or similar retaining clamp. If not, try pulling it outwards a little, to see if it can be “popped” off some concealed internal clips.

If the glass panel does not seem to detach from the rim, try similar “upwards”; “horizontal left & right”; “twisting”; and outward “popping” movements to the metallic rim, to see if it can be removed from the wall (together with the attached glass panel).

My guess is that you will be able to remove the glass panel (with or without the metal rim) to get access to the internal grate.

If so, you should then remove the “coals” (which may be a single continuous “moulded” structure or several/many individual pieces). Subsequently, you should be able to determine by “inspection” how to remove the faulty lamp (It probably unscrews anticlockwise or, if not, try pushing it inwards a little then twisting slightly anticlockwise off a “bayonet fitting”, then, if necessary, try pulling the lamp outwards in case it is mounted by “prongs”).

Obviously: after you have removed the faulty lamp you need to get a replacement. However, you should also take the opportunity to perform a visual check for loose connections (the lamp may be OK, but inoperative due to faulty wiring).

NB. If necessary, make a written record (as you are going along): of all steps taken during dismantling, so that the procedure can be reversed to enable correct reassembly. Then retain any notes you have made, in a safe place, for future use. Even if you will remember how to do it, someone else may have the same problems that you have experienced.

If all else fails, employ a qualified domestic electrician.