Originally Posted by Old-Biscuit
OP stated " I have a 10 gallon Surburban SW10DE....."
That is a standard Suburban 10 gal direct spark electric combo WH.
Normal Temp T-stat OPENS at 130*F/CLOSES for heating cycle at 100*F
High Temp T-stat OPENS at 170*F....has to be manually reset by Pushing the Button
120VAC for electric ---Left set
12VDC for propane ---Right Set
No Mixing valves used
OP has hot water AT Kitchen sink faucet (located almost directly above the hot water tank/heater).
If WH Tank Bypass was open ALL hot water would be diluted...luke warm
Farther away from WH Tank...bathroom sink faucet and shower are getting luke warm water
**Outside shower not turned off using Hot/Cold Knobs allows shower faucet to act as a mixing chamber...cold diluting hot
Kitchen sink gets hot water cause it is 1st in line on hot water from WH Tank
Bathroom sink faucet/shower....getting diluted temp water
If shower H/C Knobs are closed then you have 'lost' one of the Dip Tubes inside the WH Tank
Cold Dip tube points 'downward' so incoming cold water creates a temp zone and pushes hot out
If broken off...incoming cold water will quickly dilute the available hot
Hot Dip Tube points 'upward' so incoming cold water pushes Hot out with upper level being the hottest zone
If broken off...incoming cold will cause hot to swirl diluting the available hot
Turn water supply off
Relieve pressure...open kitchen sink faucet hotside
Remove anode rod
Using a BRIGHT flashlight look inside tank and see if you have any plastic tube laying in bottom of tank
*removing electric element will give you a better view
Replacement Dip Tubes are available.
Installed via external ports (Hot/upper & Cold/Lower)
Then just press into ports then are secured in place via the fittings for water lines