Similar thing happened to me some years ago on one of the coldest nights for 20 years. In my case it turned out to be the thermocouple(which tells the boiler that the flame is working) had failed so the boiler kept shutting off the gas valve.The gas engineer I called out knew what it was...
I'm refurbing my downstairs toilet/shower room and connecting to an unvented stub stack. In the new layout the shower will sit between the toilet and the stack. Is it OK to connect the shower waste using a very short 40mm pipe run direct into the horizontal(ish)110mm waste that runs from the...