How does plumbing do this...

[Steelharp]

I don't know the first thing about plumbing. Here's what I THINK I know. There's ONE water line that comes in and feeds everything equally. SInce my water bill is always next to nothing, there's no leaks.

 

Pressure wise, the hot water will practically knock you over; but the cold has almost nothing.

 

How does it DO that???

[Lumber_Jack]

Has it always been that way, or has there been a recent decrease? If your water pipes were soldered, there could be a solder ball inside the cold water line somewhere close to the source. Hot water should be coming out of a hot water tank, so it could have plenty of back pressure. Edited September 8, 2013 by Lumber_Jack

[peejman]

Pipe size, partially blocked line, valve not fully open, ....

[Lumber_Jack]

Could be your PCV (pressure control valve) is blocked. If you have one. Sometimes the guts fall apart and block the line.

It's located just inside the main source shut-off

[RED333]

Try the out side water hose, if it is low it could be something in the line after the

"tee" where it splits off for the water heater.

[Sam1]

Is it on every fitting in the house or just one?

[Steelharp]

Ok, more info. Didn't realize there were so many variables.

 

This is an old farmhouse. 1920's. SOME of the plumbing was replaced with PVC before we bought it. How MUCH, I have no clue. The one outside faucet seems to run fine. ALL the fixtures inside are running slower on the cold side. Toilet, showers, washer, etc. Seems like it started a while back... when I noticed it first, it was both cold AND hot. I called the water dept., and they said they were doing some work up the street, and it would be spotty for a couple days. When the pressure returned, it only came back strong on the hot. The cold has been so-so ever since.

[RED333]

Well you will have to do a bit of work to find the "tee" before the water heater.

Track that pipe to find the problem.

Most houses, the outside hose connection is first off the main line,

from there the main will tee to the water heater and the cold water valves.

[Dolomite_supafly]

If it is all the cold water in the house it sounds like it is after the split to the hot water heater. The split to the hot water heater gets full flow while the cold side has a reduced flow because of a blockage. Makes sense if you think about it. The cold would be more likely to be used than the hot so any blockage will be in the cold water pipes.

 

I am not sure what you could do. Might try turning the water off outside at the meter. Then open all the cold water faucets in the house then go outside and open an outside water spicket. That way hopefully the cold water running backwards from the house, and out the spicket, will dislodge the blockage.

 

After that it might be just a matter of cutting a line and inspecting. Mabye right before the first cold water junction and then run a rod up the pipe to try to break up or dislodge the blockage.

[RED333]

I know what it is now, old steel pipe, clogged with rust and scale, replace all the old steel pipe.

[Dolomite_supafly]

You could also use a shop vac to apply a little more suction on the blockage as well. Maybe do the same as I mentioned above except put a shop vac at the outside spicket to pull with some more force than just gravity.

[Garufa]

Seems like it started a while back... when I noticed it first, it was both cold AND hot. I called the water dept., and they said they were doing some work up the street, and it would be spotty for a couple days. When the pressure returned, it only came back strong on the hot. The cold has been so-so ever since.

 

There's your sign.  Call them back and find out what they did.  Are there any neighbors about you can ask if they're having the same problem?

Edited September 8, 2013 by Garufa

[Dolomite_supafly]

I suspect while they were working they dislodged some debris and went down the main. Then some of it came into the OP's house as he was running some cold water.

 

Problem is going to be proving the water deptment caused it.

[94user]

What are you guys talking about when yall mention the "Tee" before the water heater ?  The only connection between the hot and cold water piping is the water heater itself. Water comes into the house from the municipal water supply, or a well if that's the case and is distributed from there to the cold side of all fixtures as well as to the input of the water heater. The hot water runs in the opposite direction from the heater back into the house to supply all of the fixtures with hot water. The only thing I can come up with to explain the problem is exactly what Dolomite suggested. The main water comes into what we call a 'tieback' or also a "manifold" where it is distributed to the fixtures in the house.There is a cold water Manifold and a hot water manifold.  Piping to individual fixtures ( usuallly 1/2 inch)  is smaller than the line (3/4) inch going to the water heater. IMO most likely debris from the work on the water lines is clogging the pipes going to the cold side of your fixtures because it gets there first. Any debris going into the hot water supply will be sent into the water heater which will end up in the bottom of the heater and most likely not not end up in the supply to the hot side of your fixtures.

 

Steelharp, I'm a journeyman plumber with nearly 20 years  experience. I may be wrong but this is the best internet diagnosis I can give you.

[RED333]

What are you guys talking about when yall mention the "Tee" before the water heater ?  The only connection between the hot and cold water piping is the water heater itself. Water comes into the house from the municipal water supply, or a well if that's the case and is distributed from there to the cold side of all fixtures as well as to the input of the water heater. The hot water runs in the opposite direction from the heater back into the house to supply all of the fixtures with hot water. The only thing I can come up with to explain the problem is exactly what Dolomite suggested. The main water comes into what we call a 'tieback' or also a "manifold" where it is distributed to the fixtures in the house.There is a cold water Manifold and a hot water manifold.  Piping to individual fixtures ( usuallly 1/2 inch)  is smaller than the line (3/4) inch going to the water heater. IMO most likely debris from the work on the water lines is clogging the pipes going to the cold side of your fixtures because it gets there first. Any debris going into the hot water supply will be sent into the water heater which will end up in the bottom of the heater and most likely not not end up in the supply to the hot side of your fixtures.

 

Steelharp, I'm a journeyman plumber with nearly 20 years  experience. I may be wrong but this is the best internet diagnosis I can give you.

Junction where 3 pipes or tubes come together.

I know you have sweated a tee into a copper line, or glued or threaded pipe for one.

As old as the house is, I bet it still has some steel pipe in it.

[94user]

I misunderstood your post Red.  Anyhow I still beleive it's connected to the work done by the water department, mainly because that's when his problem showed up

[RED333]

I misunderstood your post Red.  Anyhow I still beleive it's connected to the work done by the water department, mainly because that's when his problem showed up

Yea, but getting them to cover it, well it would surprise me.

[94user]

Nope, aint gonna happen. Here in Memphis / Shelby county 99% of the time a new house is built there is no meter at the street, just the shutoff. When we do the "top out" which is installing all the drains, vents, tubs, valves, & water lines we will tie the main service to that shutoff and put water into the lines to be sure everything is leak free. Eventually before we set the fixtures to finish the job the builder will call Memphis Light Gas & Water to come out to set the meter. When they do they cut our pipe loose and all the water in the house flows out into the hole the meter sets in. They do not cap our line off. Mud & debris flows into it. We now have to tie the line back into the meter with no way to back flush the crap out of it. Sometimes the crap THEY allowed to flow into the lines clogs faucets and toilet fill valves. No telling how much ends up in the bottom of a brand new water heater. They don't care and we can't do anything about it. But they don't fail to send the monthy bill to the new home owner. :down: