Hot water flow problem

[Mohawk890]

I have a problem with hot water flow that has become progressively worse over the past month or so. When I open the faucet, whether the shower, lavatory or kitchen sink, there is initially a normal flow, but by the time the hot water gets there the flow is just a trickle. It seems to me that the problem is a restriction in the hot water effluent line close to the water heater outlet. My understanding is that the hot water does not pass through the Nautilus unit; only the cold water that supplies the water heater passes through the Nautilus thereby removing it from the equation. However, I am new to this business and I am looking for additional information and insight into this problem. I’m going to remove what I believe to be the access panel to the plumbing this morning and try to have a look-see. Any help will be greatly appreciated.

 

[Jomani]

Do you have a tankless water heater? If so, there is a small filter screen that should be cleaned at least once a year. Depending on the age of the unit, it may also be time to descale it.

 

[Rabbit]

There may be a check valve associated with the water heater that is cutting water flow. If it is stuck mostly closed, it will allow the hot water lines to build full line pressure when all hot water faucets are closed. Then, when you do open one, the stored pressure is released, giving impression flow is normal.

 

[Bonzer-MGRV]

1+ on the check valve at the water heater outlet. I had the same problem and replacing the $9 check valve solved it.

 

[Mohawk890]

1+ on the check valve at the water heater outlet. I had the same problem and replacing the $9 check valve solved it.

Thank you for the prompt response. Is it part of the outlet connector? I can’t see in there very well, but there is a 90 degree connector coming from the tank before the plastic line. I think I need to investigate that connector further.

 

[Bonzer-MGRV]

It is threaded directly into the tank.

 

[Bonzer-MGRV]

Also, you may want to drain the tank, check the anode rod and get any built up scale out of there.

 

[Mohawk890]

Thank you for the prompt response. Is it part of the outlet connector? I can’t see in there very well, but there is a 90 degree connector coming from the tank before the plastic line. I think I need to investigate that connector further.

After removal of the outlet fitting, I found that if there had been a check valve, it had been replaced with a 1” long plastic nipple. After reassembly, blew out the hot water lines back to the water heater with compressed air and flushed the water heater tank several times to waste, as well as washing the tank interior with a water wand.
I then replaced the drain plug and refilled the hot water tank with water, leaving the shower hot water valve open so as to expel any air, as suggested by another contributor in this thread. I then checked all the hot water faucets for flow and found that the hot water flows were back to normal on all three lines. Thanks to Bonzer MGRV For his assistance. Also, thanks to Likes To Tow for his assistance.