Noisy Hot water tank

Fishinfred

I installed a 30-gallon electric hot water tank to use as a backup if the propane boiler fails. The electric tank whines when it is calling one or both zones call for heat. I have installed a relay to handle the load of the two elements working together. The original T-stat controls the relay. The system has water in it now as I lost the antifreeze when a gasket failed and want to flush the system before adding antifreeze. I know the elements are the cause of the noise but am not sure how to stop the noise. I would appreciate help with this issue.

Thanks

hot_rod

typically when the elements get a scale layer on them they will quiet down

But with glycol in the system, that may not happen

Larry Weingarten

Hi, I'm just guessing, but using low-watt-density elements could help quiet things down. Using lower wattage elements could help as well. This assumes you're getting boiling on the elements and that's the noise you hear.

Yours, Larry

hot_rod

to convert watts into btu, multiple by 3.42. So if you have a 4500W element that gives you 4500x 3.41=15,345 btu. If you run both 4500 elements at once

9000x 3.42=30,780 30,780 btu. Is that enough to cover for the boiler required output?