The TPR (Temperature/Pressure Relief) valve is a safety feature that usually helps to decrease the risks of water heating system explosions. It does this by providing a way for water to escape from the heating system. And since most heating systems are closed systems, this usually reduces the amount of pressure in an over-pressurized heating system.
A TPR valve leak can be an indication of serious system problems that need the immediate attention of a qualified HVAC contractor. It can also be a sign of a TPR problem, which given the role that the TPR valve plays in helping to ensure that your home is safe, calls for the immediate replacement of the valve. The following are some of the things that your boiler system is trying to tell you when a TPR valve leaks.
You have a clogged TPR valve
Normally, the TPR valve will leak only when there is an abnormal increase in system pressure. After the pressure is restored to normal levels, the valve should close -- something that should then stop the TPR valve from leaking. However, if the valve is clogged, it will not be able to close thus causing continuous TPR valve leaks.
Debris and dirt that finds its way to the TPR valve can prevent it from closing. This happens mainly because the valve is not designed to allow solids to pass. Clogging can also happen when mineral salts are consistently deposited at the TPR valve area. Mineral salt crystals are usually left behind every time hot water evaporates. Overuse of the TPR valve is therefore bound to cause a buildup of mineral deposits that may then prevent the TPR valve from closing. Replacing a clogged TPR valve will be enough to stop these leaks.
There is a problem with your water heater's expansion tank
Expansion tanks in water heating systems are designed to enable the system to absorb any extra pressure that may arise when the system warms up. This increase in pressure usually happens because of the rapid expansion of air molecules in the system. If your water heater's expansion tank's internal bladder is damaged, if it is leaky, or if it is waterlogged, it won't be able to handle the extra pressure that results from normal system operations. This will then cause an abnormal increase in the overall system pressure, something that will then necessitate pressure relief via the Temperature/Pressure Relief valve. Replacing the damaged internal bladder and fixing any other expansion tank defects will be enough to stop these leaks.
To learn more, contact a heating and air conditioning company near you.