Intermittent Hob Burner

Over the past month one of the gas hob burners has been difficult to light.  Sometimes it would light and then extinguish.  This has become steadily more annoying so today I decided to have a closer look at it.  Jan had thoroughly cleaned the actual hob burner where the flames appear through the slots and then cleaned the carbon on the metal stalk immediately beside the burner ring.  Initially this appeared to resolve the issue, but then the problem returned!

My knowledge of gas is very limited and I therefore decided to do some googling before attempting to dismantle anything.  According to Google the small metal stalk beside the ring is a thermopile, a metal probe (round and slightly smaller than your pinky finger) that converts heat from the burning pilot light's flame into a tiny amount of electricity — just enough to open the gas valve.

So my first thought was the thermopile needed replacing.  A replacement cost around £14 and can be purchased online.  It’s only held onto the hob baseplate by a nut and I was reasonably confident about removing and replacing it if I turned the gas off first. Then a small bell rang in my head.  “The thermopile generates a tiny amount of electricity when heated”  Perhaps the nut was loose and we had a poor electrical connection.  <look for the easy solution first Tom>

A quick check with a small adjustable spanner revealed the thermopile was indeed loose!  I nipped the nut up by one full turn and the hob has been lighting without issue.  I then checked the other three thermopiles finding another with a slightly loose nut.

So if you have a burner that won’t stay alight on your hob you might want to check the nut holding the thermopile to the base is tight.