Subscribe or Renew Membership Subscribe Renew

Tie-Line Between Water Heaters ??

rw7810's picture

 New construction, 3770 sq feet,  3 1/5 bath.  Plan to put in two WH, one for kitchen and utility and 1/2 bath, the other for the 3 baths.  Plan to use two manobloc/pex home run systems.  For times when there are no guests, only one couple, does it make sense to add a tie line so that one or the other WHs can be turned off and allow only one to supply the house ??

Yes (post #206930, reply #1 of 3)


Maybe (post #206930, reply #2 of 3)

Depends on a few things:

1.)  The cost of your heat source.  The higher you cost the more it makes sense

2.)  Is the lost heat captured in a usable way.  If the water heater is inside the heated space, and you live in a heating dominated climate, where you heat most months of the year, and any "heat loss" from the water heater is going to heating a space you would normally heat any way, then it makes less sense to shut one of the heaters down. 

3.)  Is shutting one of them down, going to cause an long draw time before hot water is delivered?  If water costs are high, or water is in short supply, it makes less sense.  This can be overcome in part with a recirc loop, but then you have the heat loss from the loop to contend with. 

Personally I'd look at trying to feed 1-1/2 baths, the kitchen, and utilites out of one heater, so the other could be shut down when there arent guests in the guest baths. 

Another option would be instant heaters at the point of use. 

It depends a lot on the type (post #206930, reply #3 of 3)

It depends a lot on the type of water heaters used and the distances involved.  Highly insulated electric heaters are very low loss, and having one "idling" is pretty inexpensive.  Plus you lose heat (and waste water) if the hot water must be piped some distance from one to the other.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville