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Bosch/Miele connection to hot or cold water pipe?

Posted by janesylvia (My Page) on
Sun, Aug 31, 14 at 17:46

Is Bosch/Miele connected to the hot or cold water pipe? My current old Whirlpool dishwasher is connected to the hot water pipe.

Thank you very much.


Follow-Up Postings:

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RE: Bosch/Miele connection to hot or cold water pipe?

Miele can do either. I have my Miele connected to hot. I believe the manual said it would save more energy to connect it to cold. But there was some other benefit to connecting to hot (besides the fact that that's what the contractor did before I realized I had any options.)


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RE: Bosch/Miele connection to hot or cold water pipe?

It decreases cycle length connecting to hot if I remember correctly.


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RE: Bosch/Miele connection to hot or cold water pipe?

Connecting to cold lets you take full advantage of the China/crystal cycle if your model has one.


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RE: Bosch/Miele connection to hot or cold water pipe?

hot water conn decreases cycle by a few minutes - not enough that you are going to be able to tell during an approx 2 hour plus cycle including drying !


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RE: Bosch/Miele connection to hot or cold water pipe?

My Miele is connected to cold. I specified that at install based on recommendations here to take better advantage of the china/crystal setting in my DW. Since my normal cycle runs about 2:43 to 2:57, I figured that the cold water hookup was extending the cycle so long. Good to read above from Xedos that I wouldn't be that much better off with the hot hookup.


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RE: Bosch/Miele connection to hot or cold water pipe?

Two now connected to cold but I always have china/crystal.

If the machine doesn't have china/crystal it makes no difference except with respect to the water heater.


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RE: Bosch/Miele connection to hot or cold water pipe?

Since the dishwasher uses such little water - unless you have recently run the hot water at your sink, the 'hot water' may not be very hot - and the DW will have to heat it.


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RE: Bosch/Miele connection to hot or cold water pipe?

I would always recommend running the hot tap at your sink before starting the dishwasher to alleviate that problem. Unless you are getting a high end model with a china/crystal cycle and really want wash at low temps with it - I would just reuse your existing hot water connection.


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RE: Bosch/Miele connection to hot or cold water pipe?

Cycles on dishwashers nowadays are so long that the supply line is cooled when the rinse fills come around even if it's purged/primed before starting.


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RE: Bosch/Miele connection to hot or cold water pipe?

breezy - FYI my normal cycle in my Dimension is between 2:37 and 2:42 that I've noticed (connected to hot).

How does it decide on a length of time? Why does it vary? Anyone know?


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RE: Bosch/Miele connection to hot or cold water pipe?

Thank you very much for all your responses, which are very helpful.

Breezygirl and rococogurl, do I need to buy the new connection part for the installer if I want to have the cold water connected to the DW (current DW is connected to hot water)? The current copper connector to hot water has green layer.

I learned from my environmental engineering class at college 15 years ago that cold water is cleaner than hot water. That's why I am thinking of having the DW connected to cold water. I don't know if it is necessary to do so due to this concern.

Thank you very much.


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RE: Bosch/Miele connection to hot or cold water pipe?

janesylvia,

Before I bought anything I would call Miele tech support and ask them if there is a part needed to connect to cold water. I cannot remember any that was needed but models change and it's best to be sure.

Cleanliness of water depends on the source. However, the dw has a heater and an excellent sanitize cycle.

In my case, our boiler (furnace) supplies hot water from our tank. So with cold water hookup, the heater heats cold water and we don't use fuel to heat the water first.

Alternately, if you have very soft water or a whole house softener you would want a cold hook up.

But these are not serious issues. Older Mieles are all hooked up to cold water. Along the way they changed it to cold or hot because the usual practice was to do a hot water hookup for most American brands.


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RE: Bosch/Miele connection to hot or cold water pipe?

Good to know that my normal setting cycle length isn't too much longer than a hot water connection. Either way, it's a looooong cycle.

"How does it decide on a length of time? Why does it vary? Anyone know?"

In my understanding, the machine isn't deciding how long it will take. The number on the display is an estimate as to how long the cycle will take. It varies because of how dirty or clean the load might be. When you power on the unit, the estimate comes from how long the last load took to clean.

"Breezygirl and rococogurl, do I need to buy the new connection part for the installer if I want to have the cold water connected to the DW (current DW is connected to hot water)?"

No idea. When my installers showed up, I asked that it be connected to cold. He told me he'd do whatever I wanted and got to work. That's it.


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RE: Bosch/Miele connection to hot or cold water pipe?

Most are measuring how dirty your water is and deciding how long to wash.


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RE: Bosch/Miele connection to hot or cold water pipe?

Thank you very much for all your help.

I called Miele. Their concierge service cannot connect the DW to cold water since my current one is connected to hot water, and they don't do any plumbing work including exchanging hot and cold water valves. They said I can have a plumber to change the valves before Miele's installation.

The technical support also said the water entering Miele needs to be below 140F. Otherwise, the inlet valve in the DW might be damaged in the long run. I measured my hot water's temperature and it's 148F. I turned the dial on the boiler from A to hot, now it's 142F. Should I turn it even lower? There are two more levels lower. For china/crystal, Miele suggested a max temperature of 115F. So if I would have a Miele DW installed, do I need to adjust the boiler temperature to under 140F even without using china/crystall cycle or connect to cold water? In what situation do you use china/crystal cycle? I have many fine white plates and bowls and some glass cups.

Does Germany made Bosch SHX9PT75UC/SHX9PT55UC dishwasher also require a max temperature of 140F and crystal/china 115F? I am still hesitating between the highest-end Bosch and Miele Dimension/Diamond, and don't know if I need to hire a plumber first to exchange the hot and cold valves.

Thank you very much.

This post was edited by janesylvia on Wed, Sep 10, 14 at 16:26


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RE: Bosch/Miele connection to hot or cold water pipe?

Water hotter than 140 degrees is pretty high. The usual "recommended" water heater setting is 120 degrees, unless you need hotter water for a specific purpose. For example, you have an older dishwasher that needs to take in hotter water to wash effectively. Or, you have a washing machine without an internal heater and you want to do really hot (130-140 degree) washes. Otherwise, lowering your set point will increase safety and save energy. Most dishwashers made nowadays are designed to work with 120 degree water fills.

This post was edited by hvtech42 on Wed, Sep 10, 14 at 15:49


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RE: Bosch/Miele connection to hot or cold water pipe?

Hvtech42, thank you very much for your help. I'll lower my boiler temperature further.


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RE: Bosch/Miele connection to hot or cold water pipe?

Installation manuals for all appliances are available online, and will be a much better resource than their customer service. For dishwashers, cold supply is the exception to the rule. Almost all will call for hot, like my Bosch. Check the manual for your particular model, and maybe you'll avoid unnecessary plumbing work.


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RE: Bosch/Miele connection to hot or cold water pipe?

Terrace1919,

Miele dishwashers with a specific China/Crystal cycle that operates at a lower temperature to protect delicate dishware should be connected to a cold supply so the dishwasher can use its onboard water heater to attain the correct temperature.  Otherwise, the household hot water supply may be hotter than is intended for the cycle.


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