Glem is gas-focused, so this is a burner and trivet job. Lift the trivets, caps and crowns cold after photographing the layout, soak the enamelled parts flat in a non-caustic degreaser, and keep every product off the fascia below.
Glem Gas builds its range around gas cooking, so unlike most brands in this series there is very little chance you are looking at induction. What you have is burners, caps, crowns and cast iron.
Usually part of a stove, not a separate hob
Most Glem cooktops in Australia are the top of a freestanding stove rather than a hob set into a benchtop. That matters for one reason above all others: the fascia directly below carries the controls for the ovens as well as the burners.
Cleaner applied to the cooking surface runs downhill onto it. Spray onto the cloth rather than onto the hob, every time, because faded printed markings on a control panel are permanent and they are the most visible part of the appliance.
The burners
The general method is on our cooktop cleaning guide: trivets, caps and crowns lifted cold, enamelled parts soaked flat, ports cleared with something wooden rather than metal, and electrodes kept dry.
The Glem-specific point is the sheer number of parts. A gas-focused brand puts more burners on a hob than a mixed-fuel one does, and a freestanding Glem at 900mm frequently carries five or six with three different cap sizes. Photograph the layout, because the reassembly is where these go wrong rather than the cleaning.
Cast iron wants drying
Glem trivets are cast iron and they rust quickly in Sydney if left damp. Dry every piece by hand immediately rather than leaving them to air, and deal with the first orange patch promptly rather than watching it spread.
The wok burner does the most and blocks first
A gas-focused hob usually carries one burner noticeably larger than the others, and on a Glem that is frequently a genuine multi-ring wok burner.
It blocks before anything else on the appliance, for two reasons that compound: it does the most work so it sees the most boil-over, and it carries the most ports across the largest circumference so a given amount of debris covers more of them.
If one burner on the hob has become unreliable, start there rather than assuming a supply problem. Clear its ports first while the brush is clean, and check it lights evenly around the full ring before moving on, because a wok burner lighting across two thirds of its circumference is blocked rather than failing.
What actually goes wrong
Faded fascia markings, from cleaner sprayed onto the hob.
A burner that will not simmer, from a cap on the wrong crown.
Rusted trivets, dried by air.
Ports enlarged with a metal pin, which changes the gas-to-air mix permanently.
Should you do it yourself?
Do it yourself, lifting the burners every month or two.
Get someone in if the hob base has years on it, or alongside the Glem oven below, which on a freestanding model is the same appliance and the same visit.