Both you AND your contractor are wrong. Grout's cure time is the same as any other portland cement based product-- 28 days. However, I DO believe that most heating systems, including NuHeat allow use after 1 week past completion of installation. You might want to double check that, though, with NuHeat.

thank you Bill! My contractor did not say that the grout needed to cure for 12 weeks, just that turning the heat on after about 12 weeks was advisable to avoid problems with it.
I am curious as to what other users experience has been. When did you all turn your heat on & has anyone seen any grout problems due to this. I will ask nu-heat too, though if i ended up with any problems with grout, i doubt very much they would be of any help

Actually, I have to disagree. It's one of the reasons NuHeat is more expensive than other systems. I've worked with their reps, and these guys mean business when it comes to customer service, both for the installer AND for the end user. In spite of the way most construction material manufacturers do business, I fully believe that if there's even a CHANCE that their system is responsible for a failure, in the grout, in the tile, or in other finishes, that they'd stand behind their product. And this is coming from a contractor who is just as cynical as you are about most warranties. NuHeat and Laticrete are the only two, from all the manufactueres I use, that I'd expect no problems from in making an honest claim.

I'll vouch for Nuheat.

Someone here got into a pickle with their installer, I had some free time and they were within a few hours drive so I went over to bail them out with a little pro bono work.

The floor and wall tile job was totally botched, as well as the entire shower installation. Under the floor tile was nuheat.

I'd be able to salvage most of the tile but not the heating mat.

I called nuheat, talked for a bit, and asked if there as any way possible I could get a replacement for cost. They upped the ante and sent me a replacement system free of charge.

well, that is certainly good to hear! i will ask nu-heat what their recommendation is then & at least discuss that with my GC. winter is on its way, i'd rather not have to wait 12 weeks, but we shall see

thx a lot!