RE: [VAL] Re: tankless water heater

["David Tidmore" <dtidmore@xxxxxxx>]

Alan,
Be sure that the recirculating pump is appropriate for the task.  The
smaller pumps used in tank-type water heaters do NOT move enough water at a
high enough pressure to ensure that the tankless unit will fire as needed to
maintain the water temp in the hot water loop.  Also ensure that the
checkvalve in the recircuating loop is operational. My brother-in-law
recently had a "professional", well known plumbing company install the
latest European designed, digitally controlled tankless unit (paid over
$3000 for the turnkey job).  The results were inexcusably tepid water.  The
plumbing company tried to spin the situation as normal, but the water was
about at best between 95 and 98 degrees.  They had them out several times
but always the same excuse.  So, on my first visit after the installation, I
discovered that the installers had not checked the operation of the existing
recirculating loop checkvalve as it was corroded open and therefore was
allow cold water to back fill and mix with the hot water (the reason for the
tepid temps throughout the house.  The next problem I discovered was that
the recirculating pump was not speced at the flow and pressure ratings that
the tankless unit specified.  We replace the pump with the correctly sized
unit and that solved the problem.  They now are very happy with their
tankless unit, but were on the verge of suing the plumbing company.  They
did contact that firm that recommended and performed the installation and
they did refund part of the installation fees (which were not trivial).  I
thought it pretty inexcusable to charge such high prices, overlook such
obvious installation related components and then try to spin as normal
operation. 

david