No hot water combi boiler

It sounds like you've got a combi boiler and it's only the hot water that’s affected.

Make sure that the hot water thermostat on your boiler user controls. This is on the front of the boiler. Check it is turned up to at least the halfway point.

This is an example of a typical hot water thermostat on a Baxi boiler.

Then open a hot tap but try turning the tap down to about half-flow. This will help the water come through warmer.

Is the hot water now hot enough?