Your home's pipes are routed to each of your appliances in a certain way, and the connections of those pipes determine how your appliances and fixtures use hot and cold water. Hot water is routed through your hot water heater.

In some homes, the pipes are connected in such a way that using two appliances or fixtures can cause problems. For example, if you're in the shower and someone uses the toilet or the dishwasher, the water in the shower might turn extremely hot or cold momentarily.

If someone flushes the toilet, your shower water is likely to turn immediately hot because your home's pipes are using cold water to fill your toilet's bowl. In other words, the cold water that was previously used to keep your shower water comfortable has now been funneled through your home's pipes to a different location.

If you're in the shower and someone turns on the dishwasher, however, your shower water might turn frigid almost instantly. This is because the temperature of the water used in the dishwasher requires that most of the water stored in your hot water tank be routed to that appliance instead. There is no hot water left for your shower, so it turns cold.

This also explains why the pipes no longer deliver hot water to the shower after several people consecutively take hot showers. You've used up your home's supply of hot water and you won't get another warm shower until your hot water heater replenishes its supply.

Home owners also often complain that their home's pipes don't deliver hot water fast enough. You might have to run your faucet for several minutes before the temperature warms, and this is a problem that can easily be fixed. Insulating your hot water heater pipes will conserve energy while increasing the speed at which hot water is delivered to your fixtures and appliances.

Your local plumber can help you determine if there are any malfunctions in your home's pipes, diagnose common problems and offer solutions. In some cases, it is simply a matter of replacing a vertical pipe with a coiled copper pipe or replacing pipe joints. If you are having trouble with hot and cold water, a plumber is your best resource.

Until then, check all of your appliances to see which are operating correctly. How long does it take for hot water to reach your washing machine, your shower and your kitchen faucet? And does using one appliance negate the ability of another to receive hot or cold water? In newer homes, many of these pipe problems have been fixed, and older homes can be retrofitted with more efficient pipes and routings.