Does liquid temperature matter when making bread in a bread maker?
With a bread maker, it's important to follow the recipe closely, at least until you've got a reliable result , when you can start experimenting. 

Mine, for example, expects "tepid" water for most programs, which the book defines as 20-25&deg;C. The super rapid program requires 46-51&deg;C. Cooler and there won't be time for the yeast to get going, much hotter and the yeast will be killed before it starts to work.  This also means the super-rapid program can't be used with a delayed start, as the water would cool.

As a very general rule, slower programs will be more forgiving on temperature if you don't have a suitable thermometer and don't trust your estimation. 

You can get a very good idea of the temperature of the water if you mix boiling with room temperature, in known proportions, taking a weighted average. For example that super rapid program could use 2 parts room temperature to one part boiling, mixed before it reaches the yeast. If room temp is 20&deg;C and you mix it with actually boiling water, the resulting temperature will be (2&times;20+1&times;100)/3 = 140/3 = 47&deg;C. Ths is at the bottom of the acceptable range for my super rapid program, so I use a little over 1/3 boiling (handily it wants 260ml, so 90ml boiling made up with cold is good).