How to Replace a Backflow Preventer

Wednesday November 17, 2021
Backflow Preventer Repair | American Backflow

Are you wondering whether you should repair or replace your backflow assembly? Many a times, when an assembly fails, it’s hard to determine whether it needs to be replaced or whether it can simply be repaired. American Backflow provides the much sought after answers pertaining to the assembly repairing vs. replacing dilemma.

Repairing vs. Replacing Backflow Preventer

Usually when I find a backflow preventer that fails, I replace it with a new one. On larger backflow assemblies, I replace everything inside the unit. By taking this approach, I do not have to stock any parts on my truck and I know that the assembly will pass the test.


This is the perfect answer to the dilemma of whether to repair or replace the backflow assembly. It is perfect for everyone involved except the most important person, the customer. We have all heard this statement at one time or another. What would you think if your local auto mechanic told you that your car needed a new engine because the oil was old? Needless to say, you probably would not trust him with your business. In our industry, we are the “backflow mechanics” and it is our responsibility to give the customer the best value possible. There are situations when replacement is required, but many times assemblies can be repaired easily and economically. It is up to the technician to make the decision to repair or replace based on three basic factors: the technician’s knowledge, labor cost, and the cost of materials.

Knowledge and Experience of the Technician


The knowledge and experience of the backflow technician will ultimately be the deciding factor as to whether he will attempt to repair an assembly or just replace it. If the technician has never repaired an assembly or does not know how to diagnose the problem, he is more likely to replace and never even attempt to repair. The first time you try to repair an assembly; it may take longer and cost more than you originally thought. But it is important to remember that sometimes this is a cost to gaining knowledge. The next time you repair that type of assembly, you will have the experience that could make the job more profitable.

Amount of Labor

Backflow Preventer | American Backflow


The amount of labor (billable time) required to repair an assembly is a very important factor when deciding whether to replace or repair. Repair labor cost is normally a variable that depends on how familiar the technician is with that assembly. If he has repaired that assembly in the past, then the knowledge he gained will help make the next repair faster saving time and money.  We also need to remember that many times the labor for a repair can be much less than the labor it takes to replace and install a new assembly. Once a technician becomes familiar with an assembly, it may take him 10 minutes to open and clean or replace rubber parts on a small assembly compared to the 30-45 minutes it may take to remove and reinstall a new assembly. The main point here is that we should not always assume that a failing assembly will take a great deal of time to repair.

Cost of Materials


The last factor to consider when choosing between repairing and replacing the backflow assembly is the cost of materials. Estimating the cost of materials is pretty straightforward. The point where technicians can have trouble is, not knowing what parts and kits are available to repair a particular assembly. In some cases, a technician will replace all the internal parts of the assembly when it may only need a rubber parts kit. The difference in price between a rubber kit and all internal parts can be hundreds or thousands of dollars. The right source for repair parts is also very important for keeping repairs cost-effective. A good parts source should be able to answer questions regarding special tools, repair tips, or common field issues for the assembly that you are repairing. That information can make the job much easier, as well as, save a great deal of time and money. Remember, just as you depend on the expertise of your auto mechanic, your customer is depending on your expertise to give them the very best value as well.

All in all, when making the determination between repairing and replacing the backflow assembly, three critical factors need to be considered. These include:

  • Experience and knowledge of the technician
  • Amount of labor and
  • Cost of materials.

If the technician has repaired a similar assembly before, then it’d make sense to get it fixed. But of course the cost of labor and materials also should be taken into account when choosing between repairing and replacing of backflow assembly. The right source of repair parts can help keep the repair expenses reasonable.