on a side note, I would install something like this

http://www.homedepot.ca/webapp/wcs/stores/servlet/CatalogSearchResultView?D=938837&Ntt=938837&catalogId=10051&langId=-15&storeId=10051&Dx=mode+matchallpartial&Ntx=mode+matchall&recN=0&N=0&Ntk=P_PartNumber

It seems a bit pricey, but copper prices have come down a lot lately so you might find it cheaper. Water heating accounts for a large portion of a homes energy use. Very little of the heat is actually used in a shower, most of it goes down the drain. This can recapture it.