It happened in my own home. Everything seems normal till the Spring this year, when we started to use the garden hose to water the lawn. Within about half hour, we found one of our basement room had water all over the flood. After a bit attempt to figure out what was wrong, we decided to get a professional to get it repaired.

The plumber took the old one and replaced it with a brand new one. He explained what was happened and why this is one of the worst issues this little valve can cause. 

After a bit research, (see all the links below for more helpful info). I put together a post to share with homeowners and residents the following: 

01). Garden hose 101

02). how did the swollen happened and how to prevent it. 

03). Two most common issues and solution

04). The 5 -seconds rule. 

Garden hose outside valve, sometimes also called “Anti Siphon Frost Spigot”, is a long valve that is being installed passing through the wall so that you can use to water lawn in the yard. 

Why it is so long – the reason it is so long is to prevent the vavle from frozen in the winter. it connect the water supply from house inside, and the long stem inside to close the valve at the inner end of the valve so that when it is winter, there is no water can be frozen due the cold temperature outside. 

How doe it work – to cope with the long size, it will have a chamber full of water each time when you close the valve. Two key designs are there to help the water in the chamber drain out. 01). the plate on the wall side is tilted in a way so that there is a 1-2 degree angle that leads the water flow out upon gravity. 2). The so called vacuum break on the top outside will break the vacuum each time when the valve closed to allow the chamber’s residue water coming out by gravity. That is why it is natural to have a few more seconds (5 seconds) water dripping before it is fully stopped, each time when you turn off the valve. 

In summary, it is quite straightforward, a long valve so that i can close and open it via long internal stem. And an odd looking outside and a bit subtle installation to make sure the residual water drain out each time when you turn off the valve. 

Anything lead the residual water stuck inside the chamber could lead to this issue –  The possibilities are: 01). installation is incorrect that lead to tilt angle is flat or in the wrong direct lead to water residue remains (which is likely happen to the new home, or newer home after a few years settlement). 02). The vac-break does not work that wont allow the water drain out; 03). the water hose is not disconnected and the whole system was filled with water. 

When there are remain water in the chamber, it will start to freeze when the temperature drops down to zero in the winter and all the way to push inwards and lead to the weak part broken/crack finally. 

As it is in the winter with no use for the garden hose, this crack will not cause any issue till the next year when the Spring comes, you will have all the water sprayed out of the crack and causing serious damage inside the house. 

Here is a few checks to how to prevent it from happening again

1. Use “5-second rule” – to check the status of vac-break. It is very simple – disconnect the hose from the valve first, then close the valve and watch the dripping water continues for few more secondes (3-5 seconds). If so, no issue, if no water dripping, it means the valve working abnormally and further investigation is needed. 
2. Installation – this is very important for the new house. you need to check to make sure the installation is correct (again, a quick way to tell is the so called 5-second rule check as mentioned above). 
3. Vac-breaker – if it works incorrectly, it may cause the water stuck inside the chamber. 

In essence, make sure you apply 5-sec rule to check the proper working condition of the valve, and also make sure to do a proper winterization before winter comes which I will mention a bit later. 

Issue 01 – leaking or dripping from the hose connection. It is likely the internal parts seal is broken, replace the stem or seal accordingly. 

Issue 02 – vacuum breaker leaking. This is also a relatively easy fix – all you need is to get a part from home depot and replace it with the new one. 

The above two issues count likely 80-90% of the issue that related to the garden hose outside valve. It will be quick easy fix that can be done totally by yourself, without spend a small fortune to get a plumber to do it if you don’t have to. 

Mark your calendar and before the temperature goes down to zero, make sure the following are done;

• the water hose are totally disconnected from the valve. The hose shall have all the water drained and stored inside to be used for next year. 
• The 5-sec rule to check and make sure the valve working properly and all the residue water has been drained out properly.