First of all, it would appear from your pictures, that you have two different room thermostats installed (Photo1 and Photo 4) so maybe one of them is not connected anymore, or is used as a frost stat (is it in an outbuilding?) If so it should be set to about 5 degrees as it is only there for frost protection. If it comes on it will override the other controls and keep the heating going.
Also, you don't post a photo of any hot water cylinder thermostat. So, if there isn't one, there will be no control over the hot water temperature. It will just slowly get hotter and hotter until it reaches pretty much the same temperature as the setting on the boiler thermostat. oilheads suggestion will fix this, but reducing the boiler temperature will also cause the temperature of the radiators to drop, so the rooms will take longer to warm up.
There are still a few of these old systems around, they were installed back in the 1960's / 1970's and evolved from solid fuel installations where the hot water had to remain connected to the boiler to effectively 'waste' heat and stop the system boiling. Just the opposite of the saving energy requirement of today.
Looking at the age of the components it is time for a new system with a efficient boiler and controls that allow you to have individual control of the heating and hot water. If the radiators and their pipework are serviceable, you may be able to retain them.
