The way I understand it the Paloma heater is originally designed for residential use only.The only Paloma heaters that are adequate for laundromat usage are those that are converted by a company named Enersol;they convert or "beef up" the heaters for commercial use.I have a bank of 4 heaters for 16 tops,8 supers and 1 triple loader.The 4 heaters together deliver 24 GPM at an 80-degree rise.Unless you bought through Enersol you no doubt have a residential heater which won't give you the proper water flow or rise.Call Enersol at 517-967-3661 and I'm sure they can help you.
You may need 3 or 4 banked. They have a 3/4 inlet, so you have to set them up in a manifold system, ie, feed all them from a 1 1/2 pipe, returning to 1 1/2 so you get the pressure. I have 2 for 23 washers, and thye do well. If all of them get started on HOT then the pressure is weak. I could probably use another myself. The plumbing them is the key becuase of the small inlet/outlet