Exact Before purchase consideration which is the part back !!!

Hello There,
I bought this product on Amazon not, but at the hardware store. Of course I had to make before the Internet and Amazon tries cleverness. I've read reviews and weighed. There were statements from water is cold to the water is up to 45 degrees warm.Also I've decided to bought the device. With joy on Hot water I drove home. And was disappointed. Unfortunately, the device had suffered during cultivation, otherwise I would have given it back.
Here are some facts for you, but no scientific characteristics that are perhaps important to you.
I own an old home, uninsulated water lines. My bathroom is on the ground floor, so the cold water arriving from outside the same in the bathroom. This means, in winter the water is colder than in the summer. "Important to remember"
Since the water is cold has to bring the water up to temperature of the heater is not as much energy. This means faucet on with me and the water was not even lukewarm. Even my 11 year old son it was too cold :-(
But should you live in a new building or perhaps in the upper floor of a multifamily house, so that to warm up the water already in the isolieten lines and walls, it may be that perhaps much is your water much warmer.
Please keep in mind that when you buy. Then your water has perhaps really the temperature of about 30 degrees, such as a customer wrote.
I hope I could help you with it on.