Gas hob replacement

[ey143]

We have a Neff 4-burner gas hob bought around 2008. One of the burners has been playing up for 10 years (it doesnt ignite easily) and despite having an engineer come around and use some wire wool to clean the connection etc, he said that they are supposed to perform like this i.e. you need to hold down the gas knob for 2-3 seconds before it ignites and you keep hearing that ticking sound. Problem is after we release the button after some 5 seconds of the gas hissing sound, it has still not ignited.

My mother is elder and is getting frustrated at not being able to use one of her burners and now a second burner is playing up, reducing capacity further. Does anyone know the real reason why they do not ignite quickly and what can be done to repair them?

Second question, if we wanted to replace it, do I need a gas safety engineer to do do this or can an ordinary builder do it? Will it damage the laminate worktop or leave and gaps etc or are these generally all standard size such that it should be a straight swap?

Thx.

 

[kidgreen61]

Your hob probably has a flame failure device on it which is why you need to hold valve open for a few seconds.
They tend to be uneconomic to repair.
You will need a Gas Safe bod to install a new one, hopefully you can find one the same size, or slightly larger, and cut worktop to size.

 

[Madrab]

The process is simple, a spark jumps from the electrode to the burner crown, lighting the gas as it escapes out of the slots. If the burner crown, at that postion is dirty, gas won't be present at that point until enough is released from other parts of the burner delaying the light.

Check the spark is the same at all the burners and is consistent. Check the crown and the slots where the spark jumps to and ensure they're all clean, use some fine sandpaper to rub off any dross/burnt on food and use a hacksaw blade to clean out the slots if needed.

If that still doesn't work then the spark could be getting weak and that's the generater, only replacing it will sort that and it's hardly worth it.

If replacing the hob just get one with the same footprint size and that will cover the existing hole.

 

[ianmcd]

worktop or leave and gaps etc or are these generally all standard size such that it should be a straight swap?

No they are all different sizes, and can be a total PITA if you get the wrong size,you will need to use a Gas Safe registered engineer to replace it, but you may find it difficult finding one, most I know wont do them any more

 

[Madrab]

The OP's issue is that the burner doesn't light, not that it goes out after releasing the control knob?? It's not a thermocouple issue, it's a lighting (spark) issue ... or am i getting the wrong end of the stick here?

 

[Harry Bloomfield]

The OP's issue is that the burner doesn't light, not that it goes out after releasing the control knob?? It's not a thermocouple issue, it's a lighting (spark) issue ... or am i getting the wrong end of the stick here?

Perhaps the OP could confirm which symptom it is?

If it's failing to light at all, then a simple quick fix is to manually ignite it with a match, or lighter.

 

[Madrab]

One of the burners has been playing up for 10 years (it doesnt ignite easily) - Problem is after we release the button after some 5 seconds of the gas hissing sound, it has still not ignited.

Seems it may be a lighting issue