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[bcanode]

Installed a OWB almost a month ago. The wife is complaining about a white film on some of the dishes in the dishwasher.
We are on a well. Is this somehow related to the higher temps of the DHW? Anyone ever hear of this problem. The dishwasher is only about a 1 1/2 years old.

[slimjim]

May well be calcium that has been in the tank and with draining it you loosened it up, drain and clean the tank!

[bcanode]

Hot water heater was never drained during install?

[willieG]

if you are using a side arm it would not likely happen as the heating of the water would be passive. If youare using a plate exchanger and drawing water off the bottom of the tank and pumpiong it through the plate exchanger, the force of the pump may  push the loose calcium in the water through the system and keep it suspended in the water as it is always moving from teh bottom to the top of the tank. perhaps you could try changing the elevation at which you draw your water from and this would give the calcium a chance to "settle out" ?

[Scott7m]

Willie, hmm, I thought the opposite.  If its a plate, the tank would never know the differene because it simply runs through a box or plate exchanger before entering hot water tank, point of entry and all that would be the same as always

Id it were a side arm, the convection current of superheated water could be affecting it, because extracting water from what was the drain is def something a tank wouldn't be used to


But I'm not sure, I probably misunderstood you or something. 

[willieG]

i was thinking the user was pulling water off the bottom of the tank and pushing it through the plate exchanger with a pump and flowing water at a high gpm constantly back into the hot water tank 24/7.  this would keep the tank mixed and pulling water from the lowest point in the tank where  all the sediment would be

if using a side arm i was thinking the movment of the water being passively heated would be much slower and therefore give the sediment either time to settle or in fact not picked up at all? perhaps i am not thinking clearly?

[slimjim]

Point is guys that he says that he never drained the tank, I would be willing to take a wager that the bottom of the tank is full of calcium and just coincidence that it showed up now, my suggestion is drain the tank and clean it out as best you can by rinsing it out a few times until you get rid of the crap in the tank, the heat exchanger does not create the deposits, it is a by product of heating the water.

[willieG]

i agree that draingin the tank would surely help. i would also think that calcium would not be laying in the tank loose but would be hardened and stuck to the tank. the calcium in the water normally (only my strange thinking) settles out of the water and sticks to the annode rod or the tank walls or the bottom  of the tank. with a plate exchanger and a  pump  moving water at a high rate of speed and constantly mixing the tank it does not get a chance to settle out and "stick" to the tank, it staying suspended in the water and showing up as teh white film in the washer ?

with a side arm the water is moving much more gently and this 'settling out" can still occur, when no water is being drawn from the tank the pasive heating would get to a point where the tank would be so close to the same temp from top to bottom that water movement would be close to nil and settling would occur

this is just my thinking and i could be 100 percent wrong but to me it seems logical

[bcanode]

My water is heated before going into the HWH. OWB temp is a high of 170.
I was wondering if the calcium is not having to time to settle to the bottom. We have only been in this house a little less than a year. At our previous location I had to replace the elements on a regular basis if tank was not cleaned in time. Lost one hot water heater due to this.(The previous house didn't have dishwasher either)
I was just curious if anyone else had ran across this. I'm a little ignorant on water softener's or some type of filtering system for a fix. If the owb is the culprit. Need a scratching head icon here.

[Scott7m]

Yea Willie I was assuming he installed the plate exchanger the conventional way with no pump or any of that and simply as a pre heater

I think this is all coincidence

[skillshot]

It may have nothing to do with your owb system. We are on a well also. We had the same problem. Turned out to be the heater element in the dishwasher had burnt out and wasn't getting hot enough to fully dissolve the soap. Check this and make sure you have a rinsing agent in your reservoir of the dishwasher.