Yes, and I think (hope) it is sludge related
Turn the boiler off NOW and turn its thermostat to off or zero.
I fear the sludge has built up to a point where there is actually a blockage. This results in water not circulating properly and the bangs will be bubbles of steam forming, and collapsing, in the boiler.
It is pretty sure to need professional attention.
One thing that might perhaps help is if you buy a litre of Sentinel X400 sludge cleaner (about £15 from Screwfix or a DIY shed) and add it to the feed and expansion tank in the loft. Before doing that, tie up the ball valve float to prevent more water running into it and making it overflow, as this will wash the chemical out. Take a mug or ladle, a bucket and a sponge up with you, and bale all the mud out of the tank as you don't want that to run down into the pipes and worsen the problem. Then pour in the chemical.
If you then bleed the raduators, and let a bucket of water out, either from a bleed valve or from the drain cock if you know where it is, this will draw the chemical out of the tank and into the pipes. You can then untie the float to refill the tank, and tufn on the heating WITH THE BOILER THERMOSTAT STILL AT ZERO so that the water is circulating but not heated. Leave it circulating, cold, at least overnight. You can then cautiously turn up the boiler to minimum temp for a few minutes. If it bangs just as much, turn it off again.
This might do some good while you wait for a repair person. I imagine this is nearly the worst day of the year.
The chemical solution might not work, because if any pipe is totally blocked, water and chemicals cannot flow through it and soften it. If it does work, it will buy you a few weeks to get it sorted. After about 4 weeks the chemical loses its power and the sludge settles again.
It is very likely that a repair person will tell you you need a new boiler and/or a powerflush. It is essential that a new boiler is not fitted before the system has been cleaned or it will quickly clog.
The reason I said I hope it is sludge....
If you had an old electric immersion heater it might have a failed thermostat and be boiling the cylinder. This is extremely dangerous and you must turn off the immersion heater if the tap water gets too hot to hold your hand in. There have been some terrible fatal accidents which I do not wish to describe. Luckily a new thermostat or element can be fitted at modest cost. You may need an experienced old plumber if the cylinder is very old as the thread will be seized.