Tapping Dishwasher Off Undersink Water Heater - Plumbing - DIY Home Improvement | DIYChatroom

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing


Thread Tools Display Modes
Old 02-27-2013, 12:55 PM   #1
Join Date: Apr 2011
Posts: 97
Rewards Points: 95

Tapping dishwasher off undersink water heater

Forgive me if this has been addressed before...

I am looking at a house that has a "point of use" hot water heaters in the kitchen -- which is a long way from the main hot water heater. This small 6 gallon heater is set to a higher temperature than the main hot water heater and supplies water to the dishwasher. It connects to electric power through a standard outlet on a dedicated circuit. The water supply to this heater is off the hot water pipe to the kitchen sink.

I have never seen this done before, but was told that this was done to insure that the dishwasher would always have hot water when started -- without anyone having to run water until it gets hot. This also lets them set the gas hot water heater at a lower temperature.

Is this arrangement legal, and is a 6 gallon heater really large enough for a typical dishwasher fill? Does this arrangement "waste" energy by maintaining (with electricity) a very small tank of super heated water for use only by the dishwasher?


Perry401 is offline   Reply With Quote
Old 02-27-2013, 02:07 PM   #2
TheEplumber's Avatar
Join Date: Jul 2010
Location: North Idaho
Posts: 9,975
Rewards Points: 904

Interesting questions. In commercial kitchens, 140* is required at the DW. This is usually achieved with a point of use booster or a dedicated 140* kitchen heater with tempering valves set at 120* at all outlets-except the the DW(140)
Some residential dishwashers have built in booster heaters that raise the temp to 140* If yours does- you're DW booster should do the work and wouldn't need the 6 gal htr.
As for legal, it would be OK in my area- if plumbed correctly, including the T&P line


When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
TheEplumber is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
water heater drip kdange1 Plumbing 6 10-29-2014 05:26 PM
Tankless hot water heater during winter when water shut off jdabs Plumbing 3 07-10-2012 12:50 AM
Bosch 1600H Tankless Water Heater natemclain HVAC 13 08-24-2009 10:33 AM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1