I have a Ariston Euro combi A/23 MFFI and am looking to replace my circulating pump which is currently a WILO GOLD 50v with a single speed setting(A 0.38/W 88/RPM 2200) What would be a replacement pump that has a higher speed setting. I have been led to believe PART 996613 is a replacement part for my boiler but have come across this pump with different speed settings and would like to know what the correct pump would be to increase the flow on my system and the meaning of the settings that i mentioned earlier in the post.