I have a new gas hob which is making the bottom of my pans black like soot?

If you're using a gas stove, the gas air mixture is wrong. If you're using electric or induction, it's the residue left on the pans when cleaned.

Is this unit set up for natural gas or propane? New stoves usually come with ORIFACES for both gasses. They would install between the on/off knob and the burner tube under the stove top. They may be tapped to the under burner area of your stove. If you lift your top stove cover you may find them. If you don't find them, you may need to purchase the correct applications for your stove. GOOD LUCK FRIEND.

If you are getting soot residue, it could be a number of things, First, is this a natural gas or propane oven? If you bought an oven to be used for propane, it may need to be converted from natural gas to propane or it will soot everything up. 2nd, have you recently spilled food/liquid onto the oven burner? If the burner holes are partially plugged, the remaining holes will burn large yellow flames and soot up the oven. Check the burner flames, they should be mostly blue with little to no yellow tips. Also make sure the oven burner flames are not too big. They should never exceed the width of the flame spreader pan directly above the burner, in fact they should be less than half the width. You could also have other issues like improper air shutter adjustment to the oven burner or very low regulator pressure, but most likely it has just been spilled on recently.

You don't have the right Gas to Air ratio..... Not enough air to the burners or you are running to low of gas pressure for propane... Propane takes a smaller orfice or operate than Natural Gas.....
You should have 10" of WC for Propane operation..
You will need a manometer to check it.
The flame should be a blue color with no yellow in it. There should be air shutters right at the orfice to each burners. You will have to play with the adjustment to get the best blue flame with no yellow in the flame.... Hope this helps.....

Is this on LP or Natural gas? If LP was it converted to LP? In any event,The air shutter must be adjusted on the gas burner tube. You need more air. The valve orifice may also need adjusting.

if the hob is turning the pots black the cooker needs a good cleaning they have air ports in the burner assembly they could be blocked or the incoming gas preasure to too high and needs to be checked by a gas engineer

hi my name is mark, you can try softscrub or a glass cook top cleaner made by jenn- air or a genaric brand from the supermarket.

Hello
Tha sounds to me like the air mixture nedds to be adjusted on the stove, It's not difficult to do, just rotate it until the flames loose the yellow or your pans will be stained with soot.
The should be by the fittings (convertion fittings), you know?
LP Gas to Natural Gas or Natural Gas to LP Gas.
Hope this help
Eddie Rentas
Tupper Lake NY

Sometimes this happens if the pan bottom is not completly flat or is highly polished. Darker, flat pans work best. It sounds as if the safety is cutting off the burner.