Gas burner head - no flame from two holes

[Bertie1972]

I had all my gas system and cooker professionally serviced last year. Cooker is a 10 year old Techimpex.

Now one of the burner heads has no flame from two adjacent (of its 32) holes.

If I blow the flames towards them they light for a second then appear to go out.

There seems to be the correct amount of gas, and heat for cooking is fine.

I've taken the burner heads off thinking these two holes might be partially blocked, but all the holes look pefectly (at least to my untrained eye) clear and clean.

Any ideas?

 

[LadyInBed]

I had all my gas system and cooker professionally serviced last year.

There's your first mistake
Strip the heads down, wire brush them then wash them and refit.
How old is your regulator?
As another possibility is that the pressure to the cooker is low.

 

[Heckler]

+1 to the above

Poke a stout wire or even use a drill bit hand held in the offending holes.

If these are cast iron burner tops don't drop them onto a hard floor or do anything silly that might damage or break them. They are not fragile but replacements might not be available.
It is usually recommended that regulators should be replaced after 10 years ......... they will often last much longer but sometimes fail to operate correctly sooner ( a pressure test on the gas supply is simple to do with fairly elementary knowledge and an improvised manometer)

Yet another possibility is that he burner jet may be restricted .

Unless you are competent to work on gas systems get a Gas Safe registered gas fitter to test/ investigate.
You dont say anything in your profile about your location so it's not possible for anyone to make recommendations about who to use

Ive nearly always found that these issues occur because of too much gas velocity in the mixing chamber and it blows the flame out of contact with the ring. This combined with dirty slots in the rings gives what is described. Make sure the slots are clean and the ring is located correctly, also check that the regulator is giving the correct pressure and that the jet hasnt been damaged.

 

[JumbleDuck]

I had all my gas system and cooker professionally serviced last year. Cooker is a 10 year old Techimpex.

Now one of the burner heads has no flame from two adjacent (of its 32) holes.

I have a Techimpex which occasionally does the same. Have you tried just slackening the securing the screw and rotating the burner very slightly? That always does it for me. I presume it's a peculiarity of gas flow within the head. In my case it's often the two which play on the flame failure device which fail to light, so the burner won't stay on. I think the FFD upsets the gas flow just enough to cause the problem.

 

[Stemar]

Most burners seem to have a ring of fire around the bottom of the burner that keeps the flame on the holes from lifting off, I suspect a bit of crud (technical term) is preventing the gas getting out to complete the ring under those two holes. Take the top of the burner off and clean and dry where the ring of fire should be.

 

[KAM]

There's your first mistake
Strip the heads down, wire brush them then wash them and refit.
How old is your regulator?
As another possibility is that the pressure to the cooker is low.

Agree. I have a Techinpex. It's nothing mysterious just take the the screw out of the burner cap and give it a brush out. I find I have to do it every few years.