When you step into your nice warm shower on that cold Winter's morning only to find that all that is coming out is ice cold water you need a plumber that can respond fast and effect a hot water repair in the shortest possible time.
The thermostat is a device that controls the temperature of the water in the hot water system. When a thermostat fails it can become permanently on which means that the water is always too hot and is constantly being heated even when it doesn't need to be. This can be very costly. The other way a thermostat can fail is to become permanently off. You;ll know that this is the case when you step in to that cold shower that you thought was going to be hot.
Faulty electric element
In an electric hot water system there is a device called a heating element. It is usually shaped as an elongated coil and is inserted in the side of the water heater storage tank. Over time corrosion sets in and eventually the element will develop a short circuit or just corrode right through. Either way it means cold showers until you call the plumber. Replacing the element is actually an electrical issue but most plumbers are qualified with a restricted electrical licence so that they can perform this type of work.
If you have a gas or electric storage water heater and you notice that the heated water has started to become discoloured this can be sign that the tank itself is on the way out. Hot water storage tanks begin corroding from the first day they are used and after about 5 to 10 years they will be completely unusable. They are usually fitted with a metal rod called a sacrificial anode which helps to delay the corrosion process. Without this they wouldn't even last as long as they do.