Been available feature for years,go back and get service managers reasons for saying no.In fact there is no reason to have either on at all times unless you need hot water 24 hours a day.The water heater will still be very warm in the morning after being turned off for the night.It takes less time to recover to hot in the morning then you think,just use some energy management common sense.Have you never parked next to someone who runs their poorly adjusted water heater and it sounds like a jet next door.It usually is shutter control settings easily adjusted as per manual.