# supply point of use WH with hot instead of cold



## klempner (Mar 4, 2011)

wondering about supplying point of use water heaters (for lav) with hot water instead, as the manufacturers instruct, with cold. If the fixture is the last on a run, then by killing the hot, a dead leg is created. Would the hot water hurt the heater? The reason for wanting the instantaneous is have to wait long time for hot water. What I have been telling customers is that i would not install one unless I could cut wall (or otherwise ascertain) to make sure hot is not end of run. So customer of course hangs up and calls someone else. Any thoughts?


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## RealLivePlumber (Jun 22, 2008)

Yeah.

Laing recirc pump


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## SlickRick (Sep 3, 2009)

klempner said:


> wondering about supplying point of use water heaters (for lav) with hot water instead, as the manufacturers instruct, with cold. If the fixture is the last on a run, then by killing the hot, a dead leg is created. Would the hot water hurt the heater? The reason for wanting the instantaneous is have to wait long time for hot water. What I have been telling customers is that i would not install one unless I could cut wall (or otherwise ascertain) to make sure hot is not end of run. So customer of course hangs up and calls someone else. Any thoughts?


I had the same situation some mo's ago. I called Emax support and ask the question. The tech said it will not hurt their adj. thermostat heaters to feed them with hot water.

I haven't had a problem with feeding the adjustable thermostat models and set the temp. the same as the main heater.


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## PaulW (Jul 31, 2008)

Grundfos recirc pump.

Paul


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## klempner (Mar 4, 2011)

Rheem and Eemax say okay to feed with hot, as long as its model with thermostat (Eemax). Bosch says absolutely not. Waiting to find out about Stiebel.


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## Redwood (Sep 8, 2008)

Sounds like a lot of expense vs. repairing the hot water slab leak and recirculating...


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## Mike Jessome (Aug 7, 2008)

PaulW said:


> Grundfos recirc pump.
> 
> Paul


 Vouch!


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## Protech (Sep 22, 2008)

An ariston would work just fine.


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