Your question is in the Category Washing Machines but no matter.
Showers ALWAYS have a temperature control - it would be a crime to manufacture and sell a shower unit with no control over the water temperature. Ignore your boiler and concentrate on the shower.
You do not mention the make and model of your boiler and neither do you mention the make and model of your shower.
A more sensible or precise answer is therefore difficult.
Keep the child out of the shower until the problem is solved
Peccavi, June 2010
