hot water scary !

when first turning on the hot water in the morning,its coughing/spluttering violently and then coming out at a very slow rate.When the water settles into its snails rate I can hear the boiler fire to heat but this comes and goes.Its a Vokera compact combi,can anyone tell me if there is a fix to try myself or is it pay the piper time ???? cheers

sounds like a blocked, or partially blocked heat exchanger to me, I suppose it could possibly be a damaged pressure reducing valve, if you have one fitted?

might be an idea to get someone in

many thanks for your help. I'll get someone out. cheers