Why not flush WH with pressure?

[Cjccmc]

Most research I did recommended closing the cold water supply to the WH and just letting gravity flush the tank. When I did my flush yesterday I got a decent out flow with gravity but a much more powerful one when I turned the supply pressure back on. Why not flush with pressure, is there something I'm missing?

 

[Reach4]

Flushing can be done different ways. The simplest is to
1. Turn off the water, and put the WH in vacation mode, if it has one. Otherwise off.
2. Open a hot water tap to pass air.
3. Drain the WH completely
4. Turn the water supply on fully for a few seconds, and turn off. You are trying to cause turbulence to the bottom of the tank.
5. Do steps 3 and 4 several times. If you have a way to monitor the drained water, you could judge by what you are getting out.
6. Turn the water and WH back on. Close the hot water tap once the air has been expelled and just water is coming out.

I would consider just opening the drain to be draining rather than flushing.

More intense flushes involve spraying water with pressure in from the top or through the drain, using a water heater rinser or other probe spraying water.

 

[Sponsor]

 

[Cjccmc]

What you wrote is good information Reach4, thanks for the reply.

IIRC I think I did a partial drain about 6 months after getting my new water heater, not much noticeable solids although I did not use a strainer to see it. That was about 3 years ago and recently I started to hear popping sounds so decided to drain/flush again yesterday. Again not a whole lot of noticeable solids produced. I'm anxious to see if the popping sounds stop.

 

[Master Plumber Mark]

The best way is to flush the heater out with full power on.... Take a garden hose and run it to a drain and turn the valve on and off a number of
times to stir up the crap on the bottom.......

Absolutely nothing comes out when you have no pressure
behind it to blow it out....