Pressure Gauge Question

jim post

Please refer to the attached photo. What is the effect of the pressure in a hydronic system. I have an old Cast Iron 3zone copper fin tube system. I added water to my system by mistake the other night. Now it goes over the desired pressure (indicated by the arrow at 22psi). The boiler seems to short cycle and the temp never drops much below 160. Before I added the water it seemed the temp would range up to 170 and then the boiler would shut off and coast to about 130 before the boiler kicked on again. Should I bleed the system pressure down to the desired pressure (22psi)? Does too much water (too high of pressure) cause the boiler to short cycle? Thanks for helping me get handle on this.