Hoping someone can help here...

Been looking at numerous threads and have tried quite a few things but still no fix. When I turn on the hot water in faucets or in the shower, the pressure is immediately good but only for a second then I hear a clunk noise from under the house and the hot water pressure drops to low flow. If I turn the water off and back on it stays at this low pressure. Sometimes if I let it be for a couple hours I go back and it is fine. Then later the same thing.

I have drained and flushed the hot water heater (Gas about 8 years old) and also removed all the aerators on the faucets and the handles in shower.

Any thoughts? It seems like the immediate pressure is tripping some sort of shut off that reduces the pressure. Or is it some sort of blockage?

Hi CB

Are you sure this only happens with hot water? It never happens with cold?

If you are sure this is isolated to hot water only then I have to wonder if your water heater has HEAT TRAP NIPPLES (see image)? If your water heater has heat trap nipples, the nipples will show as having indents all around the nipple (again, see image).

Anyway, if you have heat trap nipples, the ball (if present) may be getting caught up in the nipple... rare, but it can happen and it will produce the problem you describe. Unfortunately, the only fix here is to remove the nipples and replace them with new dielectric nipples (sold at any home improvement store).

Otherwise, if no heat trap nipples see if you can have someone in the house run the hot water on and off and see if you can isolate the issue to a specific shut off or valve that may have gotten some junk caught up in it, OK?

Back to you...

Mark

Hey Mark-

Thanks for the reply. The cold water is fine. In fact, if I throw the cold on a few times and follow it quickly with the hot it sometimes keeps the hot water pressure high.

I think I may have heat trap nipples. Would love to post a photo but don't see how... Do you know if there is a way for me to attach an image? Would like to know if these are heat trap nipples that can be removed before I tried to take them off...

Thanks!

Just click on GO ADVANCED button below the box you type in (type a few words in box first) and then find the MANAGE ATTACHMENTS button on the new screen (about 2/3 way down the screen) and then when new box pops up, click on browse images, double click on image you want from your library and then click on UPLOAD at that box. Then click on POST QUICK ANSWER as always and you should be all set...

Posted another picture of heat trap nipples...

Thanks.

Just curious if you can confirm these are heat trap nipples (see pics)... Want to make sure they should be OK to come in and out before I bust out the channel locks :).

There is the slotted flanges that overlap into the threads and wasn't sure if they were there because these aren't supposed to come out. I think I'll stop off at Home Depot and get a look at what the replacements look like before I go further.

Any other tips?

Thanks!

Pics below...

From my perspective, this water heater doesn't have the nipples. Those flanges hold the respective pipes in place inside the heater. Could it be possible that buildup is partially blocking the outlet pipe? When the water is first turned on it suck sediment up against the outlet pipe?

Maybe??

From my perspective, this water heater doesn't have the nipples. Those flanges hold the respective pipes in place inside the heater. Could it be possible that buildup is partially blocking the outlet pipe? When the water is first turned on it suck sediment up against the outlet pipe??

Maybe????

I guess it's possible but when I flushed the tank it wasn't very bad. Looks like I may try to replace the nipples. The labels look worn like they went on and off before.

Yeah, that wasn't what I was hoping to see! I still hope that these are heat trap nipples I am unfamiliar with!

Easy enough to remove the hot side and check them out...