Bath Taps With Shower Mixer

[HIGH]

Hello All,
I am replacing my bath which at present only has hot and cold water taps and no shower attatchment . The bath cold feed in fact all of the cold feeds in the bathroom are fed off the mains. The new set of taps I have for my new bath is hot and cold complete with a shower mixer. My question is it ok to still feed the cold from the mains as its very very difficult to get a tank feed into the bathroom. I thought i remember reading somewhere that these should not be put on the mains? Also the hot to the bath is in 22mm and the cold is in 15mm is this correct. Thanks in advance for any replies.........Cheers

 

[ChrisR]

The shower mixing will be almost impossible to control and you also would need to dtop the cold pushing the hot back up the pipe. A pressure equalising valve is probably your best option, though may not be a perfect solution if your HW head is very low.