# Water booster heater for dishwasher



## darren (Nov 24, 2005)

I was doing some troubleshooting on a booster heater today and am curious about the elemetns, i'm not a service guy so not realy sure what to take of these measurments.

Each element is 240V and 4500W. If you do the math the resistance is 12.8ohms. When I take the leads off the elements and read the resistance it is 4ohms on each of them. Would this lead you to suspect that both elements are no good.

Thanks for the help.


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## Inplumbcon (May 26, 2010)

darren said:


> I was doing some troubleshooting on a booster heater today and am curious about the elemetns, i'm not a service guy so not realy sure what to take of these measurments.
> 
> Each element is 240V and 4500W. If you do the math the resistance is 12.8ohms. When I take the leads off the elements and read the resistance it is 4ohms on each of them. Would this lead you to suspect that both elements are no good.
> 
> Thanks for the help.


In my experience with water heater elements that would mean that they are losing the ability to heat. I would think that like a water heater element a amp draw would also prove that things are malfunctioning.


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## 480sparky (Feb 1, 2009)

You're reading the resistance while they're cold. The rating is based on when it reaches operating temperature.

To give you an idea about how this works, take a resistance reading on a normal, everyday run-of-the-mill incandescent lamp. It will show you it's 'shorted out'.


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## darren (Nov 24, 2005)

So i did some amp readings and they were within a couple of amps of the nameplate so now I know the elements are working fine.

Checked the transformer and it is working properly, check the fuses and both are good, high limit is not tripped, temp setting is at the highest.

Inplumbcon is there anything else on water boosters that I could check before I call someone in who has more experience serviceing these things. The complaint was that the water was not getting hot enough for the dishwasher.


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## Double-A (Jul 3, 2006)

Um, with a complaint such as "not getting hot enough for the dishwasher", my first question is, "How do you know?". Sometimes, what you're troubleshooting is a perception, and not a real problem with the unit. 

Have you done a draw down volume test on the unit (if it has a tank).

Have you measured the inlet temperature and the outlet temperature? What is the temperature that is "hot enough" for the dishwasher?

I'm assuming this is in a restaurant. Don't trust the thermometer on the commercial washer unless you have verified it is working properly.


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## DuMass (Feb 6, 2008)

Not sure what type of equipment you have, but if it’s a commercial rack machine then the heating elements for maintaining the wash water temp are normally located in the sump of the machine itself.
Usually, the booster heater is only for the final 180 degree sanitizing, not the actual wash cycle, so I would first check the entering water temp at the machine inlet as well as the sump elements and temp sensors to see if they are operating properly.


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