roman tub filler is only 2.5 gpm...

I made a terrible mistake! I picked the Hansgrohe 1901 Interactiv faucets and then ordered the matching shower head, valves, and roman tub filler. We are finally getting around to install the fixtures and my dear hubby noticed the input lines for the roman tub are the same size as the sink faucets (3/8" copper). I quickly got on the internet and sure enough - the flow rate is only 2.5 gpm. I assumed that a roman tub filler would be sized to fill a big tub (at least 1/2" input supply lines). since the sink and shower faucets have been installed, is there anything I can do? I want everything to match, but I'm afraid that after 20 minutes to fill the tub, the water will be cold and I will be quite disappointed. Is there anything I can do (short of returning the faucets and purchasing a set that "sort of" matches - but has greater flow?)

thanks in advance for the advise... diane

just to clarify - the individual hot and cold lines to the faucets are 1/2". Then in the mixing valve, where the water goes from the faucets to the spout, they drop to 3/8". Should I install the faucet and see if 2.5 gpm is "ok" or send it back before it's too late? thanks, diane

try it first

I dont think that you are going to
have a problem with this...
they are not going to make a roman tub faucet
fro a whirlpool tub that is going to only "piss " a stream into it.

Call the factory and simply ask them
first it that will ease your mind

but you are most likely fretting over nothing