diff --git a/HARDWARE/PID.c b/HARDWARE/PID.c
index 860ff58..1ecb554 100644
--- a/HARDWARE/PID.c
+++ b/HARDWARE/PID.c
@@ -166,6 +166,11 @@ void PID_Calc() // pid calc
 	float hd = pid.hd_h;
 	int h_base = pid.h_base_h;
 
+	// if now temp is close to set temp, the heater will be less power
+	if (pid.set_tem - pid.now_tem < 3) {
+		hp = pid.hp_h * 0.6;
+	}
+
 	// l mode
 	if (pid.set_tem <= pid.max_compressor_tem) {
 		hp = pid.hp_l;