If it is a water heater or a boiler, there is a requirement to install a backflow preventer in the cold water feed line to the appliance. This traps water inside a sealed system. As the water expands, it increases the pressure in the system until the relief valve opens. Consider installing an expansion tank.
If the water is dumping from a T&P relief valve due to temperature, the valve is bad or the temperature is too high. This requires serious and immmediate replacement and repair.