Plumbing – Why Can’t I Drain My Hot Water Tank

plumbingwater-heater

I have sediment built up in my hot water tank. I'm trying to flush it, based on instructions I've found on the internet. I've turned off the tank completely, attached a hose to the faucet drain and shut off the cold water input line. I've also turned on the hot water in the kitchen sink and bathroom.

But…every time I shut off of the cold water line, within a few seconds, the water stops flowing (both to the kitchen/bathroom and to the drain). By turning the cold water on and off, I was able to get a fair bit of sediment out, but I don't understand why I can't get all of the water out of the tank?

Can anyone tell me what I'm missing here?

Best Answer

Open a hot water tap to relieve pressure and plug the drain valve into your garden hose. Turn on the hose for a second (no longer; you don't want to push sediment into the fixtures) to loosen up the sediment.