AboutDana Bostick Expertise Pretty much any residential plumbing questions. Note: I live and work in Southern California. We do not as a rule use boilers, hot water or steam heating systems or wells so my knowledge in those areas is limited. There are others here that can probably answer those questions better.
"We all is city folk" out here! What is a "well" LOL
Experience Licensed General Contractor with Plumbing, HVAC and Electrical sub-licenses
Question I have a tankless whole-house system. One shower is about 60' away and the
water takes probably a minute to get hot. House is on a well and there is a
3200g storage tank that the well fills and a pressure pump bringing water
from that tank to the house. I think the standard recirc systems won't work
with tankless systems because there is no pressure drop. We could install
another tankless water heater in this bathroom, a small tank water heater, or
simply just put in a valve and run water from the shower back to the storage
tank. Is there another solution that comes to mind?
Answer Hello Dan,
This issue is one that has come up in my trade from time to time. A tankless system is great but does not lend itself to a "conventional" recirculation system due to the fact that the unit is s "demand" type system. They fire up and provide heated water based on a flow switch. I recirculation system would keep the unit fired all the time and soon burn it out.
There is a solution though. One way is as you suggest, install a second, smaller demand unit at the far end of the house and modify the hot water piping in that location.
This is from Takagi, one of the bigger manufacturers but would work with any tankless unit. You can check with the manufacturer of yours to see if they have any recommendations.
By using a "buffer" storage tank and running the recirculation on that system, you eliminate the constant firing of the tankless unit.
You would need to pencil out the costs involved in each to determine which would be the most feasible for you.
