Title says it all. I read and reread all the other posts asking this same question but am still unsure so let me lay it all out.

I am on city water using an electric HW heater. I have recently noticed a drastic drop in pressure on the hot side only (all faucets /showers). When I first turn the hot water on I have full pressure but after 30 -45 seconds I have a slow trickle (les than 1/4 of normal pressure). The first thing I did was drain the HW tank and put a wet/dry vac on blow at the highest faucet in the house. Oddly, no change! I placed a bucket to capture water from the HW heater drain and never saw particulates (no sand, etc). Next I turned the water back on slowly and watched the drain... no discoloration again. I let it run for about an hour to make sure the HW heater was completely flushed (and even turned the drain off twice to let the HW heater fill and re-drain). I never saw a single particulate. Hooked it all back up, cut the HW heater back on and I'm in the same situation. My question is this... did I miss anything or is there anything else I should check before cutting the HW pipe from the tank to the first junction (since this is where I would assume the clog would be)?

Thanks!
-Don

And I forgot to mention if this helps.. HW pipes are pvc.

It is only hot water correct if both remove the Aerators open the faucets see the flow, clean the screens on the Aerators install and see if it is Ok, other wise check your heater if the heat traps or installed if they are you may need to replace them, good luck.

John

Thanks for your response John. I don't aerators are a problem (I even used a blower to back push a clog into the HW heater from the faucet furthest away). Since the pressure is exactly the same on all faucets it has to be a system problem (HW heater, main pipe coming from HW heater, etc). I'm not sure what a heat trap is though. I am guessing it is inside the HW heater?

-Don

The heat traps are the nipples installed at the inlet and out let of the water heater, some plumbers don’t like to install it, see the images below if you find them installed on your heater I would suggest to remove and replace them with the regular nipples see the image, unless some one else has a better idea, good luck.

Regards,
John

Thanks for all your help! I don't remember seeing these connectors but I'll check for sure when I get home.
-Don

Hi Don,
How old is your heater? if you don't find the heat traps installed then it may be the dip tube failure, or the element failure open the link below and you will see how the dip tube works. Thanks.

John


How a water heater dip tube works and what it looks like. (http://www.masterplumber.net/electricwh/dip_tube.htm)

Hi don,

Here are some other causes for not having hot water, let me know if you need any more help,good luck,

John

Only 5 minutes (http://www.masterplumber.net/electricwh/only_5_minutes.htm)

Thanks again for your answer John but I think we are looking at it from 2 different angles. I don't have a problem with running out of hot water. The only problem I have is low hot water pressure. If I let it run I have enough hot water for a normal shower but the pressure is low. That's why I am leaning towards a clog between the HW heater and the first junction in the pipe. Make sense?
-Don

Don,

Dis regard my post #6 and #7, I mixed the pressure wit heat, thanks.
John