There are several reasons for your coffee to taste bad. Please see if one of the following will solve the problem.
Use drinking or distilled water
The quality of the water greatly affects the taste of coffee. If you’re using tap water, try using bottled or filtered water instead.
Make sure your coffee has not gone stale
Coffee loses its flavour over time, more so if it is ground. To get the best tasting coffee from your appliance, use freshly roasted and ground beans. Using a grinder and grinding the beans right before brewing will improve the flavour. Make sure that you store your coffee in a cool, dry place.
Make sure your coffee is grinded for use in a filter coffee machine
The coarseness of your coffee grind makes a huge difference in the taste. French press, espresso machine or a filter coffee machine all require different levels of grinding for best results. If your coffee is weak, your coffee might be under-grinded. If it tastes bitter, your coffee might be over-grinded.
Clean all parts
There may be something in your coffee machine that affects the flavour. Unplug the appliance and clean all parts that will come in contact with water and coffee. Keep the appliance unplugged during installation and cleaning.
Clean the coffee jug and the filter basket with warm water using a small amount of mild cleanser. Dry them both thoroughly before usage. Run the appliance once without coffee, using only water and then pour it out.