# reason for water supply blockage?



## bob_cntrctr (Jan 30, 2008)

Gentlemen,

This should probably go in the plumbing forum but I'm on site and in a hurry and more see this area.

In a duplex, side by side, all plumbing is in the separating walls. Bathrooms are back to back. Bathroom layout from left to right is toilet sink tub with each fixture branching off the lines running the length of the wall. Bathrooms are mirror images of each other. Seperate supply line for each apartment. Apt 1 has both hot and cold water to all fixtures. Apt 2 has cold to toilet, hot to sink, but not cold, and neither to tub. I would normally conclude frozen pipes except Apt 1 pipes are in the same vicinity and not frozen. Running the hot water for half an hour has made no change to the tub hot supply and the blockage occurred during the day when it was only 28 degrees. Whereas this plumbing is 5 years old and has never frozen even at -10 F. 

So I would be appreciative for any alternative theory.

Thanks.


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## wyoming 1 (May 7, 2008)

Bob how hard is your water. I have a house we do some maintainence at and every thime you turn the water off all the crap in the lines plugs up both the shower heads and strainers but I have also had it plug the supply valves and faucet and shower inlets. I would start at the sink turn off the supply valve and disconect the supply line and then SLOWLY turn on the supply valve and see if you get water if not turn off the main and take off the valve then have some one slowly turn on the main if still no water and you are sure it is not froze start taking it apart.


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## threaderman (Nov 15, 2007)

cntrctr,sounds dangerous,if you don't get it never mind.:laughing:


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## boman47k (Oct 13, 2006)

You didn't just drain the water heater did you? If so, and you did not open the faucets with strainers removed when it filled back up, they can clog with trash/sediment that settles in the bottom of the heater.


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## bob_cntrctr (Jan 30, 2008)

Thanks guys - 

it won't be the strainers 'cause on the sink the hot water flows. But I was hoping someone would say they had at least once in their life seen scale/crap clog up the line/valves. I'll start there.


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## MALCO.New.York (Feb 27, 2008)

I would bet that somehow, I know not the reasoning in this situation, that a vapor-lock has worked itself into this array.............

The ONLY reasoning for a "Spontaneous" blockage on a supply line that I can think of.


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## threaderman (Nov 15, 2007)

You will have to work your way backwards through the system starting at the fixture,process of elimination,and you will find what ails you.No miracle cure here.


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## RayGoerdt (Nov 13, 2008)

Has there been any recent plumbing work from the house main to the bath in question in either apt? The newer shower valves are not too difficult to plug up with line debris, and the sink may be the same. But as stated earlier backtrack the lines and you will find the problem.

Let us know what you find out please.


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## boman47k (Oct 13, 2006)

bob_cntrctr said:


> Thanks guys -
> 
> it won't be the strainers 'cause on the sink the hot water flows. But I was hoping someone would say they had at least once in their life seen scale/crap clog up the line/valves. I'll start there.


I have seen something similiar, but only with old galvinized pipe.


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## bob_cntrctr (Jan 30, 2008)

Well, the mystery continues. 

The next day the temperature went back abve 32 and coincidentally both hot and cold started flowing at the same time. The bath faucets were left open with the plug in during the day while I was there roofing, and suddenly both hot and cold started flowing around noon. There was a little copper oxide in the water on the bottom of the tub, but not enough to explain a blockage.

So, temperature rises, water flows, you think obviously frozen pipes. But (a) what the odds that both hot and cold would un-freeze at exactly the same moment? (It wasn't he main supply line 'cause there was cold water to the toilet the whole time.), and (b) like I said, this plumbing has seen O-degrees F and colder for five years and never frozen before - no reason to imagine why it would now at just 25F.

Lord, I'm gonig to have to open the wall - darn.


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## RayGoerdt (Nov 13, 2008)

Thanks for the update, that is strange how they both came on at the same time, I would be interested to know what you find in the walls.


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## Ron The Plumber (Oct 10, 2006)

bob_cntrctr said:


> So, temperature rises, water flows, you think obviously frozen pipes. But (a) what the odds that both hot and cold would un-freeze at exactly the same moment? (It wasn't he main supply line 'cause there was cold water to the toilet the whole time.), and (b) like I said, this plumbing has seen O-degrees F and colder for five years and never frozen before - no reason to imagine why it would now at just 25F.
> 
> Lord, I'm gonig to have to open the wall - darn.


Odds are good.


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## bob_cntrctr (Jan 30, 2008)

UPDATE - So, I pulled the toilet and the sink and cut a ~18" high swath of drywall from the floor up, from the bathtub to the opposite wall. To my amazement, there isn't single supply pipe. Instead, the pipes are under the floor in the crawlspace, with branches rising up to the fixtures. No problem, except this is a ~8" crawlspace, dirt floor, and near the bathtub the dirt rises until the pipes are in fact lying on the ground. It would be consistent with what happened that this would be the area that froze, and it makes sense that if they were going to freeze, the part lying on the cold ground would go first.

Still doesn't make sense why it would happen this year at 25F after surviving 5 years no problem - but maybe something that's been doen there has re-routed cold air into this cavity.

So, I dug out a few inches of dirt from under the pipes, put down vapour barrier on the ground, then I stuffed a bunch of insulation in, under the pipes, extending out either side as far as I could reach into the cavity. Then I left some insulation off the inside of the wall I opened, and closed it back up, basically forming an insulated shell that's open to the inside of the wall but insulated from the ground.

Now we'll see what happens the next time it turns cold.


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## bob_cntrctr (Jan 30, 2008)

UPDATE 2 - been several days now at 20F, and no problems. Everyone keep those fingers crossed.


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