We had a Vaillant EcoTech Pro combi installed about 2 years ago and dont find the hot water hot enough, its about hand hot,my question is do these type of boilers ever need to have a de-scale? I have turned the water pressure down and has made a difference but obviously this effects the speed it comes out of the taps. Any advice would be grateful.
I would say get the flow rate checked against the boiler first. It is possible that it needs de-scaling but it may be gas rate is too low due to undersized gas supply pipe. A good engineer could check all that on a service.