nope as long as the gfci is protecting the load side wires. I have seen relay systems that were not GFCI protected.
If you put a GFCI breaker on the same circuit as a GFCI Tstat it will nuissance trip...unless it's a GFPE (30ma) breaker.
I shouldn't, the only problem of daisy chaining GFCI's is troubleshooting, you never know which will trip first or even both, I have had many calls because an outside receptacle was dead only to find it was also fed from a garage receptacle that was already GFCI protected, the home owner reset the outside GFCI but didn't know that the garage GFCI had also tripped.
With two GFCI's, the resistant load of the element will cause one of the GFCI's to trip...sometimes! Electric floor warming systems should always have their own circuit. All manufacturers of electric radiant specify it. If you don't install a separate circuit, it can void their warranty. (don't shoot the messenger!)
With two GFCI's, the resistant load of the element will cause one of the GFCI's to trip...sometimes!
I don't think there is a requirement in NEC for GFCI protection on these heating systems - it is a manufacturer recommendation / or even listing requirement.
See 424.44(G)
Does a 220 volt wall heater in a home need gfci protection?
Good find - I opened my mouth without even looking. I will point out that according to that section GFCI is only required for floors of bathrooms and in hydromassage bathtub locations. Although not a requirement in other areas it is not prohibited and may be a good idea - at least at the equipment protection level.
Well, GFCI would not be the correct term for it. GFCI breaks at around 5-6ma. Line voltage floor warming and exterior gutter mealt systems require GFEP (or GFPE) breakers which break at 30ma, as mentioned earlier in this thread. So, if you use GFCI at the main, you would need to use a GFEP at the tstat with line voltage floor warming elements or one of them will nusisance trip.