How to Winterize a Backflow Preventer

What You'll Need
Insulating tape
Plastic bag

Backflow preventers are a common way of preventing waste water from travelling back up pipes and systems, and contaminating drinking or washing water. If you have one of these backflow systems in your garden, perhaps attached to a sprinkler system, then you may decide that you need to winterize it over the cold season. This is a great idea if you live in a cold climate which experiences a lot of snow, even if your backflow device is actually below the frost line, as they can still freeze or burst if they become cold enough. If you have one installed in your water pipe system, then you will definitely need to get it sorted before the cold season is upon us. Anyone with a little home improvement knowledge, and following a few simple rules, can get this done quickly and efficiently.

Step 1 - Remove your BackFlow Preventer

The first way to protect your backflow preventer from damage during the winter is simply to remove it from the ground. This is the best method if it is attached to something such as a sprinkler system, as you can remove it without the risk of causing damage to pipes and other surfaces. A backflow pipe which is above ground can simply be removed using a wrench, and then drained of the water inside it. Once it is dry, you can remove it to a shed, or even inside the house, and then replaced in the spring.

Step 2 - Tackling a Below Ground Backflow Preventer

If you have a below ground backflow preventer, then you will need to dig down to your pipes in order to get access to it. Most backflow preventers have a union connection which holds it in place. Using your wrench, you can uncouple these from the ends of the preventer. You may also have to use a screwdriver if the connections have been fixed to the sides of the pipe. If you don't have a union connection, you will probably have to saw out the backflow preventer, or protect it in some other manner. A successfully released backflow valve can be drained of water, dried, and then stored over the winter months.

Step 3 - Protecting in the Ground

If, for various reasons, you cannot get the backflow preventer out of the ground, then you will have to use other methods to ensure that it remains operable in the cold weather. One method of doing this is to wrap it up using insulating tape. Place this around the whole of the backflow valve, making sure that the strips of tape overlap in order to give you a good seal. You can use standard insulation tape, or even fiberglass tape if you wish. You may also lag the valve using waterproof insulation and tape to hold it in place. However you insulate the backflow preventer valve, you should then cover over the insulation and preventer using a plastic bag. Secure this, and then cover over the valve with earth, and leave until spring.