Water heater - No water coming out

[Paresh]

Hi

I am a newbie DIY as it relates to plumbing - but am in general handy with tools and other items at home.

Last evening the hot water across all the faucets stopped (except for trickles). I flushed the water heater and it seemed fine. As soon as I close the water inlet valve, the flushing stops and as I open the valve the flushing comes back on. Based on this I presume the water is going in the heater. I cannot figure out if the water coming out is an issue. I don't think the faucet or other pipes are clogged (I back flushed the faucets using a dime to push the cold water through and it seemed to be fine).

I opened the hot water line on top of the heater and it had a triangular plastic piece in the water heater - wasn't sure if something is getting stuck on the output in the water heater - I couldnt pull it out and was worried about breaking something there. The other thing I also noted was the tank doesn't seem to hold much water (it is a Rheem 40 gal). As soon as I start flushing, if I stop the inlet valve, it immediately stops . This is even after waiting 30-45 minutes of no flush, in which case I would presume the tank should be filled and the flushing should continue just from the tank even if I close the inlet valve.

Any advice / help on this one? I probably will have a plumber come and look at it later today.

thx in advance
Paresh

 

[Reach4]

What happens if the drain is open, the supply valve is closed, and you open the hot water tap in the kitchen or laundry sink?

I get the impression that most plumbers don't repair water heaters. How old is your WH?

What is that bit about the dime? Are you sticking coins in your plumbing????

 

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[Paresh]

@Reach4 - If the supply valve is closed - there is no water (no drips either) that comes through the laundry sink. I haven't tried that with the drain open - will try it later this noon. The WH is 7 yrs old.

For the backflush the dime mechanism works - and yes I did not loose the dime in the plumbing .. --

http://www.thesuperhandyman.com/?page_id=158

thx
Paresh

 

[Jadnashua]

To drain a WH, you need to let air get into it for the water in it to drain out...otherwise, it's sort of like your finger on the end of a straw.

Since it's not a new install, the heat traps are not likely installed backwards, but they might have become clogged up while trying to drain. Heat traps work as sort of a one-way valve. They open when there's pressure from the water flow, but close when it stops to prevent convection currents from draining away heat. They probably are not clogged up, since the debris would tend to go down and out verses rise to the top, but maybe. You can open the T&P valve to let air in, but on an old tank, they don't always reseal properly. While a WH can last a lot longer, average gas fired ones tend to be around 7-8 years.

 

[Paresh]

Thanks Jim - I will check the T&P valve and see if it makes a difference. I cannot figure out why the tank might not be filling at all or so it seems (as right now the drain and the inlet valve seem to in-sync very closely). We have a major extension planned for next year when I am hoping to move to a tankless. So I was trying to see a way out of this one if I can for another 6 months. Worst case I will go for a tankless and will have to move it with the extension.

-Paresh

 

[Reach4]

Last evening the hot water across all the faucets stopped (except for trickles). I flushed the water heater and it seemed fine. As soon as I close the water inlet valve, the flushing stops and as I open the valve the flushing comes back on. Based on this I presume the water is going in the heater. I cannot figure out if the water coming out is an issue.

By "flushing stops" I presume you mean that water does not flow readily out of the WH drain. Without a hot water tap open to provide air, that part sounds normal to me.

On the other hand, your hot faucets not getting water when the WH water supply is open is hardly normal.

I opened the hot water line on top of the heater and it had a triangular plastic piece in the water heater

Suppose you open that hot water line again and turn on the WH supply. You would expect water to flow freely to the floor, unless you have done something to reroute the water. If your WH is in a water-tolerant area, you might try that.

 

[Paresh]

Did some more tinkering - the water flushes only while the inlet valve is open, irrespective of whether the hot water tap is on or not. The same with T&P valve. The T&P drain only drains the water then inlet valve is open. But both the bottom drain and the T&P drain works fine with decent pressure, except it almost is like that the tank does not hold any water. Having said that hot water is not flowing in the outlet pipe. The heater is not in a great area, so I cannot keep the outlet top open and see if it water spurts out, but the laundry sink is right next to it and I can see the pipes - so chances of those pipes being blocked is minimal.

The only explanation I can think of is that the hot water outlet is blocked somehow from within as well as tank is filled with sediment so much so that it doesn't retain much of the water. I cannot still explain the whole thing but maybe I just need to replace this one.

 

[Reach4]

Suppose you close the inlet, open the drain, *and* open the T+P valve?

Changing a water heater that is full of water is hard.

 

[Paresh]

Tried that as well and no water comes out from either - close the inlet and open the drain and open the T+P valve (and open and close the faucets as well). To me it seems the whole thing is empty and it starts draining as soon as the inlet is opened (probably too naive a view).

 

[Paresh]

Ok - got a plumber a figured out the issue. The nipple on the hot water outlet was blocked. That blocked the water coming out. Additionally because it was blocked, the pressure from an open faucet never got in the heater to push the water out from the drain - hence the drain only worked when the inlet valve was opened. He changed the hot water outlet nipple and connection pipe and everything seems to be back to normal. Thx everyone for their suggestions.