Bad odours coming from your plumbing isn't unusual and can have many different reasons. As it can affect all the rooms connected to your plumbing and cause an unpleasant living environment for you and your family. Bad odours usually have quite simple explanations and can often be sorted with rather simple solutions. The only thing you need to do in order to decide how to fix a problem with bad odours coming from your plumbing is to figure out what is causing it.
A common place where strong smells are accumulated is the bathtub or shower drain. Hair, pieces of skin, and remains of soap and shampoo are mixing together in the drain, forming a slimy, smelly liquid that sits in the pipe, unable to be flushed down. The first thing you should do is to clean the drain out as well as you can, as this mixture is hindering the clean water from flushing the slimy liquid out. After that, you can pour a mixture of baking soda and vinegar down the drain. This will create a chemical reaction, which will help removing the entire slimy residue that is left after cleaning.
Your bathroom sink is another place where odours tend to form. The vinegar solution might be applicable also here, but to properly clean it out, you should remove the trap under the sink and empty out the still standing water in it. This will also empty out the dirt that has been building up. To clean it thoroughly, you can also use some sort of chemical cleaner to flush through the upper part of the pipe and flush it out through the disassembled trap.
One of the most common reasons for smells and blockage in the kitchen sink is cooking fat that has been poured down the drain and that has then coagulated in the pipe. This blocks the pipe, but also attracts pieces of food and dirt that also are flushed down the drain, causing a plug of smelly materials. One thing you can do to get rid of this plug is to heat the visible part of the pipe under the sink up with a hairdryer or a heat blanket that you wrap around the pipe. This will cause the coagulated fat to melt and you can then flush it out using hot water.
If your washing machine smells, the easiest thing to do is to do a cleaning wash. This means that you put the machine on the hottest wash possible, while using laundry detergent, and wash the machine without clothes. This removes any build up of fat and dirt that has accumulated in the washing machine without you having to do any actual cleaning. This could be done more times if you don't notice the smell go away after the first time.
If you're worried that the smell coming from your drains might be indicative of a larger issue, however, such as a septic tank or sewer malfunction, don't hesitate to reach out to local plumbers to find out what's going on.