How to Find and Fix Plumbing Crossover
The most common homeowners’ complaints we often receive are - “not enough hot water” or “hot water runs out quickly.” These issues can sometimes be the main symptoms of a plumbing crossover. Here’s how to prevent, test, and repair a plumbing crossover successfully.
Plumbing crossover can occur in any domestic hot water distribution system. Crossover allows an unplanned flow of hot water into the cold water system or cold water into the hot water system, resulting in high energy losses, long wait times, temperature fluctuation, and discomfort. That’s is why it needs to be taken care of on time and correctly.
Plumbing crossover is when cold water gets into the hot water system, or hot getting into the cold system.
Every domestic plumbing system has a hot and cold water supply divided into two main loops, but cold water can still mix with hot and vice versa without you noticing. And that can be a problem.
The risk of getting cold water into the hot water supply system is even higher, especially in today’s modern new and remodeled homes that use mixing valves, check valves, and single-handle faucets, the primary sources of crossover.
Highlights of plumbing crossover symptoms
A hot water pipe is cold or not enough hot
Cold water is warm
Water temperature fluctuates (cold water sandwich)
The most common causes and locations of a plumbing crossover
Single handle faucet
Mixing valve (solenoid on the washing machine)
Check valve
Hot and cold water pipes mixed up
In general, there are several reasons why the plumbing crossover problem happens. Some symptoms are easy to recognize, making repairs simple and quick, particularly for handy-people. There are also problems with no visible signs of crossover.
For the homeowners who would prefer professional service, its always best to contact a skilled professional.
As mentioned, a single-handle faucet is often found “guilty,” for the plumbing crossover. Many homes have single-handle faucets because they are much more user-friendly, installation is simpler, and adjustment is easier. They are also more popular than two-handled faucets because they can help prevent burns because cold water is mixed in.
Mixing valves are next on the list of potential reasons. Mixing valves are widely used in plumbing to protect users from scalding temperatures. These valves are found in automatic washing machines.
Faulty check valves on recirculation systems or anywhere in a plumbing system. Check valves are used to direct water in one direction only.
How to test for a plumbing crossover
It is very easy to test for plumbing crossover. Here are the steps to take:
Turn OFF hot water at the water heater.
Turn ON all hot water faucets.
Wait for several minutes until the water flow stops.
If you see any water flowing, then you have a problem with the plumbing crossover.
Next, turn OFF all the faucets.
Open only one hot water tap at a time, then switch to the cold water side. If you see or hear water flowing, you just located where the problem is.
Test all other faucets, as there might be more than one crossover.
You can also test it this way:
Close the main shut-off valve that is supplying cold water to the water heater.
Open the hot water faucet only on a double-handle faucet if it is installed. If there is no double handle faucet, and you have only a single handle type, you must do the test twice and each time using a different tap. If the faucet is showing crossover, it should be tested in the off position as well.
After some time, the water should stop running completely. If hot water is still running but at a slower rate, your shut-off valve is defective, so replace it.
If the water turns cold and continues to run, you have a plumbing crossover problem, where cold water is crossing over to the hot water side.
Check all the incoming water pipes that lead to a single-handle faucet. If you find both cold and hot water pipes cold, you have crossover.
If, after testing the whole plumbing system, crossover still occurs, you might have a situation where some other aspect of your boiler or water heating system is not functioning correctly. In these cases, it’s always best to call a professional.
How do you repair plumbing crossover?
Typically, plumbing crossover is not hard to repair. Depending on the location, it requires replacing the faucet cartridge, check valve, or mixing valve. Keep in mind that replacing the cartridge does not always solve the problem. However, buying a quality faucet, or even a cartridge, could prevent the crossover problem.
As we know, every residence has cold and hot water pipes. Hot water is produced inside a boiler or water heater, supplying various faucets, appliances, hot tubs, and pools.
In residential homes, water is usually heated to the maximum temperature of 140 F, and depending on the exposure time, it can produce severe burns. According to the experts, hot water temperature should be in the range from 120 to 125 F. Water is safe to use (free of bacteria) at this temperature and can do the job efficiently.
This is why following manufacturers’ instructions is important and calling a skilled professional technician our best advice.
Conclusion
While plumbing crossover is a common cause of a “no hot water complain”, there can be a number of issues that also lead to a domestic hot water system not operating correctly. Contact an expert as soon as you notice atypical heating behavior, and avoid energy losses, high energy bills, and cold showers.