Recently my ancient simplex hot water system failed. IT WAS REPLACED WITH A STEIBEL ELTRON SYSTEM. THESE ARE 3 PHASE ALSO. My main concern is the installer just cut off one of the water pipes at the top of the old simplex system and used the other 2 to connect the new system. I now seem to have a lot of water hammer, hissing from pipes, and different taps dripping and hissing. does any one know if this is related to the new work or just a coincidence.