Intermittent hot water mystery...

[DAA]

So, I just sat down to google this, and thought "hey, RME is BETTER than google!". There always seems to be people here that have the answers to just about anything like this that comes up.

Issue:

Kitchen sink with single handle Moen faucet (kitchen area in the office). Hot water suddenly stopped working yesterday. Not cold water instead, no water.

So I replaced the cartridge (a 1225). Still no hot water. Again, I don't mean cold water instead, I mean when you move the handle to hot, no water at all.

Three other sinks (two of them on the other side of the same wall), a shower and a washing machine all on the same water heater, all still running hot water just fine.

Sooo... I did what I should have done before replacing the cartridge. I checked the hot water supply line. Nothing coming out. Not a drop. Took the line off from the valve to the sink, line not plugged, no hot water coming from the valve. Sitting there, scratching my head, playing with it, and a little bit of flow started to come out. So I hooked it back up. Turned on the faucet and it's flowing hot water perfectly normal.

I stand there watching it for a couple seconds, saying right out loud "WTF?!" and as soon as I say that, the water stops flowing instantly. Like somebody threw a switch. Full flow to zero.

So, to summarize. Hot water supply valve coming out of the wall, suddenly stopped flowing yesterday. Other faucets on the same water heater, including one in a bathroom straight through the wall from this sink, are all still flowing hot water just fine. While messing with it a few minutes ago, this one started flowing just fine again, for no reason I can think of, but only for a few seconds then it suddenly cut off again.

So, what in the great world of plumbing is going on here?

Thanks!

- DAA

 

[boogie_4wheel]

If I understand this correctly, every time you turn the faucet from off to on you get a few seconds of flow then it quits. But does it completely stop, or does it continue to dribble?

Sounds like the line is almost completely plugged, and allowing a small amount of flow through. As the faucet sits in the off position, the hot line pressurizes, and when you open the faucet you get a short duration of flow.

But the real question is what is causing the problem... It could be that the isolation valve at the wall has failed internally, or there is something in the line behind the valve.

 

[DAA]

If I understand this correctly, every time you turn the faucet from off to on you get a few seconds of flow then it quits. But does it completely stop, or does it continue to dribble?

Not exactly. Every time I turn the faucet from off to on, I get nothing - not even a drop. But, a little while ago, I turned it on and it flowed perfectly normal, which surprised the crap out of me, but only fore a few seconds and then it went to zero again. And is still at zero. No dibbles. Hot water side only. Cold is flowing normal.

- DAA

 

[DAA]

I think next I'm going to try shutting off the supply at the water heater and removing the sink supply valve at the wall. No idea how or why that valve would be plugged, especially not how it could come unplugged for a few seconds and then completely plugged again instantly. But, that's the next part in the chain, so I don't know what else to do but pull it off and have a look.

- DAA

 

[jeeper]

I'm guessing plug behind wall valve, allows Sloooow flow. After sitting for a while it has allowed enough flow and pressure to build up that you get a short burst of flow when the faucet turned on. Shut water off at water heater, removed valve at wall, look inside for clog (if daring, place bucket under wall pipe without valve, turn hot water on water to see flow.. But be quick and use two people to avoid wet mess)
Replace with new valve.

 

[DAA]

Okay.... few questions:

Do you have a pressure reducer or any other safety items plumbed in the vicinity?

Do you have a water softener?

How old are the braided supply lines? Perhaps it's pinched?

No pressure reducer or anything like that I'm aware of. If so, it's hidden in the wall.

No water softener.

All the lines, everything, is about ten years old. The line from the valve to the sink is clear though. With that line removed, no water is coming out of the valve when it's opened.


But, so, I just messed with it some more and am pretty sure the valve itself is either plugged or gone bad somehow. I decided to remove the valve for a look see. When I started to get it loose, some dribbles came out of the pipe (water turned off and lines mostly drained using other faucets). So, it looks to me like water is getting TO the valve, it's just not getting past the valve.

I wasn't able to finish removing the valve to know for sure though. Right about the time those dribbles came out and I was thinking, yeah, it's this valve, my neck, which had a disk removed and a plate put in two weeks ago, spoke up and told me in no uncertain terms I was DONE messing with this for a couple of days...

I'll give my neck a couple days to recover and mess with it again on Thur. or Fri. though. Thinking I just need to get that valve off and go match it up with a new one and re-install. I hope!

- DAA

 

[sawtooth4x4]

My hot water hose from the water heater into the piping gets clogged up. I have to shut off the valve once a year and remove the sediment build up. just an idea.

I probably need a water softener.

 

[rockdog]

Dang Dave, I wish you didn't live so far away. I'd come over and fix it for you. Don't mess up the work the doc has done on ya. It's painful enough going through it one time. Don't want to do it again.

 

[thefirstzukman]

Has the water heater temp been turned up somehow?

 

[DAA]

Interesting question on the temp. So, the water heater is up on the mezzanine and there's not any way to get up there without bringing my ladder over from next door. Which, nobody, except me, ever, has any reason to do. So, impossible that anyone has messed with the temp. But! When I was up there yesterday looking at it, the temp control is electronic and it looks to me like the control might not be working - no lights and I couldn't get it to respond pushing the temp buttons.

- DAA

 

[SLC97SR5]

I know it may be weird to have an internet stranger in your home but I'm out running around and would be happy to swing by and swap in a valve.

 

[DAA]

Ha-ha! I'd take you up on that, but it's at the office in SLC. And I'd still take you up on it, but I'm going to be out most of the day.

Appreciate it though!

- DAA

 

[Cherokeester]

Deposits can build up in the water heater and completely impede the flow of the hot water. You can google ways to try and clean it but it is hard. It might be time for a new one. Try opening the drain valve to the water heater and see if it flows.

 

[DAA]

Valve at the wall fixed it.

Seems like a strange failure, but, I guess I don't care, now that it's fixed. But, when I took the valve off, and opened it, I could blow through it freely - it wasn't blocked or plugged at all. But I could see a washer inside that looked out of position and squished a bit. Apparently when the full water pressure hit it, it somehow moved and totally blocked off the valve? And this happened just sitting there? Since I don't believe that valve had actually ever been used since the day the faucet was installed and it was turned on.

Just seems strange to me.

All good now though. Thanks everybody!

- DAA