I replaced the hot water valve. Two days later, a whining noise appeared when hot water was flowing to the machine. Initially, when the water begins flowing through the hot water pipe and the water is still cool, everyting is fine. The whining noise starts a bit later, when the water pipe is hot. What else could be wrong? Could it be the other valve (cold water?) I noticed that the cold water valve has two water connections, one of which is connected to the hot water pipe.

SOURCE: only hot water pipe going in

Don't know that particular make, but if there's only one water inlet available the machine should use its own electric heater. A "Wash Temp" setting switch should be available.

SOURCE: Bosch Maxx WFL 2060

connect at random. put on a rinse cycle. if cold water comes in then pipes are correct. if hot water comes in then pipes are wrong way round and just swap them

SOURCE: Cold water or cold & hot water connection?

If there is only 1 water connection on the back of the machine then it's a cold water supply only and the machine will be fitted with a heater element to heat the water. If it has 2 water connections then you need the hot supply and should ask someone to fit the correct isolation valve on the capped pipe so you can fit the required hose. Most modern machines are cold water only.

SOURCE: my bosch classixx 1200, my washing machine leaks

Remove top and check that they are your fill vaulves. Your hoses should be connected to them if so.If they are leaking on inside of machine when off then they need replacing.

SOURCE: just bought a new washer

Hi from retired Englishman in SW France,

You just need to collect the cold pipe- the washer does the heating itself for hot washes. It uses the water cold for rinses ;-0)
And for a manual-

you will need to type into your search engine/web browser '(make) washer manual' and you should be presented with a number of sources from which you can either download for free or have to pay a nominal amount. During the process you will be asked for the actual model number!

Good luck,
John C.