Yes, That means you might choose to consider the climate you're in before finalizing your purchase. Since the tankless water heater heats the water while it passes through the system, the temperature of the incoming water may have an influence on the flow speed that's coming from your water heater. The good thing is means for those in colder climates, your drains will not be as efficient because your water temperature will have to be raised much higher and could lessen your circulation rate. This might not have a radical effect on the efficacy but it is something to consider when making your purchase. Just remember that the colder your climate is, the less leak rate your tankless water heater valve kits will create.