DIY Doctor UK DIY Forums

Hi, I have an intermittent issue where the hot water to the taps and shower from our combi boiler sometimes decides to run cold. The pressure to the taps has always been low, as it takes ages to run a bath even when the water is coming through hot. Having investigated I think the problem only occurs when the central heating is also drawing from the combi, would that explain the issue and why is this? Do I have a problem with the boiler or the water supply to the boiler?

Thanks in advance