How I flush my HW tank

[Banjo Bud]

I'm not sure this is the "approved" way to flush a tank but it works well for me. I turn the inlet water off, then hook a hose to the drain. I open the drain and at the same time I open the pressure relief valve. Then I have a fitting that fits at the end of the pipe that comes out of the relief valve that allows me to inject air from a compressor into it with an air gun. I inject air into the tank through the open pressure relief valve until the water runs pretty strong out of the hose. Then I stop and let it drain for 30 seconds or so and then do it again. I do this until all the water is out of the tank. Then sometimes I'll refill the tank and do it a second time. This seems to push a lot of crud through the hose. I know there are other ways to flush a tank but this is how I prefer to do it.

 

[Terry]

I open the drain with the water still on to the tank. This helps to clear the sediment at the bottom under force. Then I turn off the water and open a hot side faucet inside the house to let air back in the tank as it drains.

 

[Sponsor]

 

[Reach4]

Flushing and draining are different. Routine flushing is for removing the accumulated sediment at the bottom of the tank.
Watch the stuff come out if practical, and that will give you a gauge on if your flushing frequency is enough.
Running the first bit into a white bucket would be ideal for this. Post a photo if what you get is impressive and you don't mind sharing.

That said, I did something more complete process like you did. I had the anode of my gas WH at the time. After draining, I alternated spraying water in the anode hole and turning on the supply. I also did some with laundry detergent, and then some with phosphoric acid. I got pebbles out in my process. No pebbles will come out in the future, because I put in filtering. I also got black material out, which I think was mostly iron sulfide, but I am not sure. The iron removal before the softener and the powered anode should limit the FeS generation.
I have wondered about using an electric pressure washer with a small-enough head to play around inside.

Going forward, I can limit my flushing to the power flush that Terry describes. I am planning to do that soon in conjunction with some water treatment stuff.

 

[Banjo Bud]

Pressure washer (electric or low powered gas) sounds like a great idea if you’re careful. My HW tank is electric. I’ve thought about pulling the lower element out and spraying in the hole to agitate some of the crud and goop up.

 

[Reach4]

Pressure washer (electric or low powered gas) sounds like a great idea if you’re careful. My HW tank is electric. I’ve thought about pulling the lower element out and spraying in the hole to agitate some of the crud and goop up.

A few pressure washers can suck from a bucket. That would let the bucket/tub serve as a settling place, and limit how much water goes down the septic.

 

[Whoodle]

perfect timing; was just thinking that I haven't flushed my 50g Vertex unit since I got it almost 2 years ago!!! Anything special I should do or look for? Will I get a lot of gunk coming out if water was softened & 'iron-filtered' before hitting the heater?

I just checked, AOS says I should flush it every 6 MONTHS, is that really needed, given that water is conditioned first? It's a hassle; have to run 75' hose outside thru the house cuz I don't want to put 50-75g thru the septic all at once, and I cant run hose out the window cuz the tank wouldn't drain below that level.

 

[Reach4]

perfect timing; was just thinking that I haven't flushed my 50g Vertex unit since I got it almost 2 years ago!!! Anything special I should do or look for? Will I get a lot of gunk coming out if water was softened & 'iron-filtered' before hitting the heater?

You tell us. Consider playing the first stuff into a light-colored container.

I will say that 2 years is much shorter than average, because the median time is never.

 

[Banjo Bud]

Well I drain about 2 gallons out of mine every 2 months and flush it as I described above every year and my last tank lasted 15 years. However, I replaced it as a preventive measure. It wasn’t leaking. It might have lasted longer. I replaced the anode at 9 years. It was 80% gone.

 

[Skeezix]

Opening a hot water tap to allow air to enter the heater tank when draining it, as Terry Love suggests, may or may not work. It certainly does NOT work with all systems (like my system, for instance) because the loops in the hot water piping allow water to be trapped. The best way to let air into the tank while draining (and the only way for my system) it is to first close the cold water inlet, release the pressure by opening a hot water tap, and then open the T&P valve. That method works for me. Just be sure to close it after the tank has been drained.

Also, replacing the piddly little plastic drain valve with a full-flow ball valve will allow the water to drain at a much, much faster rate.

 

[Banjo Bud]

Also, replacing the piddly little plastic drain valve with a full-flow ball valve will allow the water to drain at a much, much faster rate.

This is probably the best advice.

 

[Fitter30]

With opening the pressure relief valve and blowing compressed air back through it. It would be idea to have spare valve for when it starts dripping.