3 dishwashers - all within 2 - 18 months stop heating water - why?

Thanks for answer. However, surely if this were the case then new dishwasher would never have generated warm water? I am sure if i get a new dishwasher it will work for a couple of weeks generating warm water

…and then break and everything will be cold just like the past ones.

I agree it must be something external to the dishwasher though.

Any other Thoughts?

Hi,

Have you checked the temperature of your hot water supply at the dishwasher?

It may be that it is not warm enough and if the problem with the dishwashers is always the heater failing then perhaps the heaters are on for too long trying to heat the water in the dishwasher to the correct operating temperature.

Over time this could affect the heater element.

For example on some dishwashers it is specified that the hot water supply should be 120 deg F and that the temp used for the Normal wash cycle is 120 deg F but for the rinse cycle it is 140 deg F so presumably the heater is only used for the rinse cycle and not the wash cycle, and only has to raise the temp 20 deg F when it is on.

Just a thought.

Hi. Thanks. My assumption was that the dishwasher took in cold.water and heated it up. If it needs the water to already be warm then this makes sense but in the summer when I hardly ever heat water, I would not expect my dishwasher to work, when in normal circumstances it would.

Putting this to one side, how and where would I check what you are asking me to check? On the boiler or ?

Thanks

James

Hi,

That was my point.

If it required hot water and you supplied cold then the heater would be on for a longer time heating the water.

You need to check the installation guide for the dishwasher to see the requirements.

You could check the water at the boiler as long as you were satisfied that it wouldn't lose too much heat before it reached the dishwasher e.g. due to hot water pipes not lagged and/or exposed to air etc

Alternatively, using an appropriate thermometer, you could check at the water outlet to the dishwasher, just disconnect the water hose from the tap and run some into a bucket. This way you'll also find out as what happens in most cases that the water is cooler (cold?) initially until the hot comes through. It may depend on how long this takes i.e. how much water has to flow before it becomes hot and therefore how hot the water actually is in the dishwasher as it will be shut off by the float switch when the required amount is reached

You could always get a dishwasher that specified cold water inlet only. That way you're guaranteed that the heater circuit is designed to heat from cold and not from a raised temperature.

This will cost you more power obviously

My Bosch dishwasher specifies cold water but hot can be used IF it is tempered to 60 deg C (found out this was to protect the "plastics")

I have solar hot water (100 deg C -212 deg F for at least 9 months of the year) tempered at the dishwasher with cold water to 60 deg C to save power heating the water