# Poor Hot Water Pressure After HW Heater Flush



## linuxrunner (Oct 18, 2010)

Recently flushed our electric hot water heater (about 2 yr's old) and although it seemed to go fine we now have significantly worse hot water pressure. Cold water is fine, but the hot water is really bad now. Hot water is a little less than 1 GPM, cold water from the same faucet is over 2.5GPM. As far as i know i flushed correctly, my steps where as follows.

Power off to water heater,
hose hooked up to drain at bottom of heater
inlet water valve for heater turned to off position.
Open drain valve.
Open a few faucets to hot position.

After almost no drainage i did pop the pressure valve at the top of the heater and water begin to flow out the drain hose at that point. 

Once it seemed empty i opened and closed the inlet valve for the heater a few times to flush out any crud. 

so did i do something wrong?  not sure what is going on here but it's pretty clearly something I did because we had better hot water pressure before i touched it. 

And yes i have checked like 5 times that the inlet and valve for the water heater is all the way opened.


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## Homerepairguy (Aug 1, 2010)

linuxrunner said:


> Recently flushed our electric hot water heater (about 2 yr's old) and although it seemed to go fine we now have significantly worse hot water pressure. Cold water is fine, but the hot water is really bad now. Hot water is a little less than 1 GPM, cold water from the same faucet is over 2.5GPM.


Is the low hot water flow from every hot water faucet? If even one hot water faucet in sink or bathtub flows normally then it makes all the difference in troubleshooting the problem.

If all hot water faucets have low flow, then you probably have ball type heat traps for your water heater. The heat trap for the hot water line is probably clogged with sediment from your flush. If this is the case, I would remove the ball type heat traps on both the cold and hot water lines to/from the heater and install "U" type heat traps in both pipes.

If even one hot water faucet has normal flow, then the clogs are at the problem faucets.

HRG


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## secutanudu (Mar 15, 2009)

The inlet valve may be stuck partially closed....


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## linuxrunner (Oct 18, 2010)

Homerepairguy said:


> Is the low hot water flow from every hot water faucet? If even one hot water faucet in sink or bathtub flows normally then it makes all the difference in troubleshooting the problem.
> 
> If all hot water faucets have low flow, then you probably have ball type heat traps for your water heater. The heat trap for the hot water line is probably clogged with sediment from your flush. If this is the case, I would remove the ball type heat traps on both the cold and hot water lines to/from the heater and install "U" type heat traps in both pipes.
> 
> ...


:thumbsup:

Yes all the faucets have low flow when running hot water.

Sorry for the ignorance, but the heat trap right after the in and outlet pipes? right where it connects to the top of the water heater? Also i have heard that you can bend a u or circle in a flex water line to function as a heat trap any idea if this is true?

I will go home and check the heat traps.


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## Homerepairguy (Aug 1, 2010)

linuxrunner said:


> :thumbsup:
> 
> Yes all the faucets have low flow when running hot water.
> 
> ...


Heat traps are to prevent hot water from rising from your water heater so by definition would be right above the water heater. Here's a picture of hot and cold heat traps:









I suggested replacing with "U" type heat traps but more correctly should have said "S" type heat traps (turn the "S" 90 degrees). Just the shape of the pipes into and out of the water heater. I prefer this method since there's nothing that can go wrong with them.

Make sure your heater is really flushed out well so you don't have the same clogging problem repeated. If possible, replace the gate drain (hose bib type) on your water heater with a ball valve with hose bib output which will allow better flushing due to the straight through path through the ball valve. If you do this, be sure that you remove the handle from the ball valve or install a cap very tightly on the valve since a child could turn the handle and get scalded.

A side benefit of replacing a gate type drain with a straight through ball type drain is to insure being able to get water out of the heater for drinking in case of an emergency and there is no water pressure from the city. Gate type drain valves could be clogged by sediment and not allow draining water out of the tank.

HRG


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