[ryaowe]

The shower in my master bathroom has stopped working (only a trickle of water comes out), so I thought maybe the valve had broken. I replaced the valve cartridge (it's a moen posi-temp 1222), but the problem persisted. I tried pulling the cartridge back out, and then turning the water back on. It turns out I get lots of pressure from the cold water, but nothing at all from the hot.

My house has a manifold where the hot/cold water is split and sent to individual fixtures, rather than a common line with tees for each fixture. I disconnected the hot water line for my shower from the manifold, and then turned the manifold valve back on to make sure hot water comes out there, which it does.

When I hook the PEX line back up to the manifold and turn the valve on, I hear a small amount of water rush into it, but then it stops (the cartridge is still out in the shower valve, so the water should run through).

So I think this means that the PEX line is blocked somehow. The line doesn't run along any exterior walls, or cross any combustion air lines, so I can't imagine it is frozen... but I could be wrong.

The house is only 8 years old, and doesn't have particularly hard water, so it also seems unlikely for there to be that much sediment buildup... but again, who knows.

Can anyone recommend a way to clear the clogged line? I tried blowing air through it with my compressor, but haven't had much luck so far. Replacing the line would be difficult, since the master bathroom is on the top floor of a two-story house, and the manifold is in the basement.

Thanks for your help!

 

[jmon]

I would say both your suggestions could be posible. Either frozen or blockage somewhere.

Try hair dryer on the line.

Please wait for the plumbers to respond. Thanks

 

[Ghostmaker]

https://www.moen.com/shared/docs/instruction-sheets/mt692c.pdf

Read up under flushing.

 

[ryaowe]

Thanks for the suggestions so far. The flushing section in the Moen manual says to remove the cartridge and turn on the hot and cold water, but even with the cartridge removed, I don't get any hot water.

I've tried a hair drier on all of the exposed parts of the line without any luck.

Would it be a bad idea to try and snake the line?

 

[2x_Tom]

What are you snaking it with? Sticking one of those fish type snakes down there won't hurt anything actaully it might give you the exact distance to your blockage (or the closest fitting). Don't stick a normal drain snake down there or you'll be changing the line. Have you tried disconnecting from the manifold and the body and blowing air both pays? It's also possible the line has become kinked. I've seen tight bends kink after a few years of use. I've also seen lines freeze 8' into a house from a draft. What I've never seen is a line clog itself eight years after installation.

 

[Yodaman]

why do you suspect the line to be frozen? Did it freeze last year? Are you experiencing unusually cold temps?

When PEX tubing wraps around a corner the shape flattens out a little. Sharper the corner flatter the tubing gets. Too sharp and it kinks. Maybe something dislodged from within the HW tank and clogged at a corner where the mat'l has flattened. Can you disconnect from the manifold and try to back flushing with air from the shower valve?
I see no reason you could not snake a pex line. I would use a # 12 or thicker bare copper wire, but you will not go around a 90 degree fittings

 

[SeniorSitizen]

Until the line is disconnected at both ends then checked for flow it can only be an assumption the line is clogged.

 

[ben's plumbing]

if you remove the cartridge and turn on water and nothing comes from hot side ...you are right its clogged...next question where.....if you access to back of unit and piping... try tapping on the fitting by the diverter sometimes its clogged right there... tapping moves junk around and my free up a clog if its there...

 

[Yodaman]

was this a gradual flow reduction or all of sudden?

 

[TheEplumber]

If you have integral stops on the valve- it may be clogged. You should be able to disassemble it and run a test.

 

[ryaowe]

It was a sudden reduction. I did discover an exterior wall where the line runs, so I'm thinking it is probably frozen... The pipe isn't exposed there, so I can't get to it with a hair dryer.

I've only lived in the house for a year, so I don't know if it has frozen before. But it has been 0 to 20 degrees outside for the last couple of weeks.

Snaking didn't go very well... too many bends that I couldn't get through.

I guess I'll see what happens when it warms up outside.

 

[SeniorSitizen]

Typical plumbing mistake. Water lines run on the wrong side of insulation within exterior walls. If this is the problem it may be spring thaw before water in that line is again available unless you heat the exterior.

 

[Alan]

Nevermind. I read faucet, not shower.
Too early.
I'm going back to bed. <_<

 

[Yodaman]

The last time a had a frozen line I used this heater, setting on the washer pointed up in the direction were the pex line fed into the wall cavity. After a few hours the line broke free.

http://www.homedepot.com/catalog/productImages/300/26/261a0d05-90a6-4353-9d52-0d15db23af5d_300.jpg


just a thought, good luck