tankless or dishwasher issue?

[justanotherjbr]

Hi All,
I've got an odd issue that I would appreciate some advice on. I have a very similar issue as the gentleman in this old thread:

Water to dishwasher not hot enough to melt soap completely

i have a GE dishwasher, only 2 years old. Always worked fine. Now there’s soap residue running down the door when cycle complete. I called a repair service who checked everything, then told me there’s nothing wrong with the dishwasher and that will be $75. They said maybe my hot water to the...

terrylove.com

Home is about 10 years old and came with builder installed GE Monogram dishwasher and a Rinnai V75 tankless water heater. Dishwasher filter is regularly cleaned and the tankless is flushed on an annual basis and the flame rods have been serviced twice (cleaned once and replaced once).

A few days ago I noticed that the dishwasher's detergent cup was not being cleaned out like it should. I should note that for years I've been a proponent of not loading anything on the lower rack, front side so as not to block the spray arm from cleaning out the detergent, so that's not an issue. Jets on the spray arm seem to be clean. We always consistently use the "Light" cycle on the dishwasher for the last 10 years as well.

Here's where it gets weird. After much running and re-running of cycles attempting to clear the detergent cup I noticed something that I'd never seen before - opening the dishwasher, there was no steam. The dishwasher has been running with cold/room temperature water. Something suddenly changed a few days ago such that the dishwasher will no longer cause the tankless to fire up. Using the kitchen faucet and showering is not an issue. This is driving me crazy, any ideas if this is a water heater issue (flow sensor?) or if it's a dishwasher issue somehow?


Thanks in advance.

 

[Fitter30]

Look at the bottom spray arm holes could be stopped up not washing out the detergent cup. Water temp up to 120°+?

 

[Sponsor]

 

[WorthFlorida]

As Fitter30 suggest, water flow can be reduced buy clogged up spray arms, the flow sensor doesn't trigger.

I should note that for years I've been a proponent of not loading anything on the lower rack, front side so as not to block the spray arm from cleaning out the detergent, so that's not an issue. Jets on the spray arm seem to be clean. We always consistently use the "Light" cycle on the dishwasher for the last 10 years as well.

Should not use the light cycle, use normal. Most dishwashers now have internal heaters to get the water to the proper temp during the wash cycle regardless of inlet temp. If you have a sanitary cycle, it'll bring the water to 140 degrees.

Remove the spray arms and run a cycle to prove the flow sensor is working with full flow. It should since the sink faucet is working. If it is still cold, something is probably wrong with the DW pump or there is a clog that feeds the spray arms.

My Samsung DW has a screened filter that sits below the lower spray arm That occasionally needs cleaning.