Any plumbers here?
For the last two days I've not had any hot water coming out of my taps, either upstairs or downstairs. I do get water out of them still and it's slightly lukewarm but still colder than room temperature, the radiators meanwhile seem to work just fine.

This is a standard combi boiler in the UK, I haven't changed or done anything to it that I can think of. I'm trying to at least narrow down what the problem could be is.