[RE-wrenches] On Demand Heaters for SDHW

[SOLARPRO at aol.com]

In our area of so cal, gas water heaters with SWH last as long as fifteen  
years no problem, and 20+ years is not uncommon - w/o anode rode redo.  But  
the ODWHs with which I am familiar usually need de-liming (service call)  
about every five years.  I do not have much data with ODWH with solar  
back-up, yet.  The larger the family in both cases, the faster the  failure.
ODWH manus seem to be claiming that the savings of standby heat loss is 15% 
 minimum, but if your heat loss is from standing solar heated water (which  
entered the tank when somebody last used the hot water) and you have set  
the outlep temp of the solar 15% higher than that of the old  fashioned water 
heater,  your heat loss is from solar heated  water.
The irony about _endless_ hot water is this - most of the people who have  
installed an instantaneous heater that is unassisted by solar will actually 
have  higher gas bills, specially if there are any teenagers in the house.
 
 
Patrick A.  Redgate
AMECO Solar, Inc.
Serving Solar California
Since  1974
7623 Somerset, Blvd.
Paramount, CA  90723
562-633-4400


_www.solarexpert.com_ (http://www.solarexpert.com/) 
_www.amecosolar.com_ (http://www.amecosolar.com/) 


In a message dated 9/17/2010 9:36:59 A.M. Pacific Daylight Time,  
toddcory at finestplanet.com writes:

"repairable unit - you  don't have to trash it every seven years (reported
national  average)"

My tank is 20 years old now. I change the anode every 3  years.

Todd





Sent from Finest  Planet  WebMail.


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