No water pressure on hot water side

[f457930]

I just replaced the anti siphoning valve for my black tank washer.  While it was off and after I replaced it I lost water pressure on the hot side of all my faucets.  I have good pressure on the cold side.   it dribbles a little water when the faucets are on hot.  It acts the same on city water or on the house pump.  If I bypass the water heater I get pressure when the faucets are turned to the hot side.  I don't think there is any connection between the valve change  out and loss of pressure.  Anyone have any ideas?  

[desertdeals69]

It sounds like the heater has a restriction.  

[ianbullock]

Sounds like the backflow preventer is stuck in the closed position obstructing the water flow?

This is usually located on the main feed line out of the hot water tank.  

 

[kaypsmith]

9 hours ago, F457930 said:

just replaced the anti siphoning valve for my black tank washer.  While it was off and after I replaced it I lost water pressure on the hot side of all my faucets.

I don't know what that valve looks like, but it almost sounds as if it is turned backwards. An anti siphoning valve is no more than a checkvalve, if there is an arrow, then it should be pointed in the correct direction of flow, although I have seen those mis labeled from the factory. You can take the device back out and blow into it in the direction of the arrow, if you cannot get air through, then blow in the other direction, if air passes then it is mis labeled, if no air passes in this direction either, it is a faulty device. Is the black tank washer tied to the hot water flow somehow?

[ianbullock]

Sorry when I said "backflow preventer", I meant "Checkvalve".  Not sure if this is related to the anit siphoning valve you replace related to  your black tank washer.

[kaypsmith]

Sure seems coincidental that the problem only occured after the anti siphoning device was replaced, that is why I would start there to correct the problem. My black tank washer is me, and I always use hot water to wash the black tank. When I return home after a trip, the hot water is still hot, I pour hot water, calgon, and a cup of dawn dishwater liquid into the black tank, after all, the crud in there is a large percentage grease, that is what makes it like to stick to a carrier. Of course, I empty the tank again immediately after washing it, then add a few cubes of ice just for laughs.

[wildebill308]

13 hours ago, F457930 said:

I just replaced the anti siphoning valve for my black tank washer.  While it was off and after I replaced it I lost water pressure on the hot side of all my faucets.  I have good pressure on the cold side.   it dribbles a little water when the faucets are on hot.  It acts the same on city water or on the house pump.  If I bypass the water heater I get pressure when the faucets are turned to the hot side.  I don't think there is any connection between the valve change  out and loss of pressure.  Anyone have any ideas?  

Ok, lets review, the black tank washer/flush is not connected to any outher part of your water system, right?

Make shure the valves are turned all the way in the hot water bypass system. not just the handles as they have been known to slip on the shaftes. If that isn't it replace the check valve on the hot water heater. Let me know what you find.

Bill

[f457930]

It was the check valve on the hot water discharge at the water heater.  Took much longer to access the compartment than it did to change out the valve.

thanks for the help.

 

[wildebill308]

Glad you got it fixed now go have some fun.

Bill