Undersizing or oversizing valves in a hydronic system can have significant consequences on system performance and efficiency. Undersized valves can lead to inadequate flow rates, increased pressure drops, and reduced heat transfer, resulting in poor system performance and decreased efficiency. Oversized valves, on the other hand, can cause unnecessary energy losses, increased wear and tear on the valve, and reduced system controllability. In extreme cases, undersized or oversized valves can lead to system instability, reduced reliability, and even premature failure of system components. Therefore, it’s essential to properly size and select valves for a hydronic system to ensure optimal performance and efficiency.