Tankless water heaters do not provide instant hot water to your points of use – to do that you probably would need a re-cir system.

Re-circulation pumps or systems are a tricky issue on tankless water heaters. The main premise of a tankless water heater is that it only heats the water you use and therefore provides substantial energy savings. Re-circ. compromises these savings sending out hot water to keep a loop of piping warm until water is used, this is quite costly, I’ve seen it cost as much as $150.00/ month.  So that starts us recommending timers to minimize the run time.

Now another issue needs to be looked at, as discussed in another blog the minerals(lime & calcium) re-crystalize when heated and form hard water deposits which reduce any heaters efficiency & can also cause heat exchangers to run too hot and fail.  Now the goal becomes to eliminate the flowing of heated water into the tankless water heaters inlet,  keep it only seeing cold water at it’s inlet. This can be accomplished by the use of  re-circ. pumps or Tankless Return Solutions systems.

Tankless Return Solutions is a system which uses primary & secondary loops to keep the water warm in the plumbing loop with only part of the water when the temperature drops a predetermined delta “T” being sent thru the tankless heaters to maintain a preset temp. in the loop. This system works extremely well but is probably best suited to large residential and commercial projects due to it’s higher initial cost.

Tankless water heaters will work fine with re-circ. as long as some of these issues are considered as the system is designed &  installed.