Most water heaters are set between 115 and 135 degree's F.
all the gear I have ever had documentation on states to store in cool (up to 80 degree's F), dry and dark storage. 5 minutes at 115 degree's is about as close to cooking the stuff, but does it render/cook off the active ingredient????
Are you having gains on the heated injections???? if not, that might be the answer.