If the pressure relief valve has no pressure, it is likely that the balance hole has become clogged, the spring is broken, or the valve simply has a loose fit. If the thermostat were out of control, the tank could explode IF there is no TPR. There's simply no other way to release excess pressure under the right conditions. And when a PRV fails, it can cause an explosion.
It can cause damage to equipment, interrupt workflow, and even injury. Why take that risk when you can easily tell if your pressure relief valve needs to be replaced or repaired or not? If you see that the pressure relief valve is leaking, flooded, or if you hear strange noises coming from your PRV, it's time to replace it. Extreme pressure causes the gasket that seals the oil filter of the engine block to break down, causing serious oil leakage and loss of lubrication of the engine. A water pressure relief valve (PRV) is vital for reducing incoming pressure from the water supply source.
A problem with the pressure relief valve can damage the engine oil filter and the engine itself. As the pressure of the oil that is created in the system increases, the valve piston is forced against the spring and causes it to open. Damage caused by a faulty pressure relief valve often causes the engine to have to be rebuilt or replaced. It is suitable for low-pressure steam and water service, and is ideal for use in household water heaters and supply tanks, table heaters, jacketed steam kettles, unit heaters, low-pressure steam systems and steam coil heaters. A PRV will operate only as long as the water supply pressure does not fall below the preset PRV pressure.
