The boiler is overheating because water isn't circulating through it. You say the pump is running- have you set it to manual maximum rate and can you hear it running (won't be a lot of noise, should be a faint hum and on a recently refilled system you should hear the odd air bubble as the water is moving through the pipes.
If the leak is from the drain cock (2nd pic in your last post) it's irritating but not to be worried about at the moment- it will not be causing your heating problems. The red valve in pic 1 in your last post is more of a concern- is that dripping from the stuffing gland? Has it been altered by your 'engineers'. Can you post a pic showing more of the pipework (trying to determine what that gate valve is doing and whether it should be open or closed).
Just a final one- pump valves. Lefty loosie, righty tighty? Don't use gorilla force but you will need a spanner on the shafts (shame they didn't fit better valves but they could have done worse)
If the leak is from the drain cock (2nd pic in your last post) it's irritating but not to be worried about at the moment- it will not be causing your heating problems. The red valve in pic 1 in your last post is more of a concern- is that dripping from the stuffing gland? Has it been altered by your 'engineers'. Can you post a pic showing more of the pipework (trying to determine what that gate valve is doing and whether it should be open or closed).
Just a final one- pump valves. Lefty loosie, righty tighty? Don't use gorilla force but you will need a spanner on the shafts (shame they didn't fit better valves but they could have done worse)