# Hot and cold flucuation in the shower.



## 907plumber (Mar 13, 2010)

I was out looking at a well tank replacement when the customer also complained about the shower pressure as well. One moment the temperature being fine and the next moment they will get a cold blast and I guess this will happen for the duration of the shower.

They said it only started happening after the downstairs bathroom was remodeled. The problem is in the upstairs. THey still arent using the downstairs as that is not ready yet. But, the valves are installed with the cartridges in place, just no trim on.

The new valves that were installed were moen, the upstairs is moen too. Their water heater is a 15 year old amtrol boiler mate.

The well tank is a very small xtrol. probably about 15 gallons. Its a 2.5 bath house, but a fairly large house.


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## Qball415 (Nov 20, 2010)

Moen.....Cartridge!


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## billy_awesome (Dec 19, 2011)

Hmmm. since you said they renovated....

Maybe some solder is stuck up in the cartridge!


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## rjbphd (Feb 5, 2010)

Geeezzz man,,,,


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## gitnerdun (Nov 5, 2008)

What kind of moen is downstairs? Non pressure balanced? Maybe they have the shower nipple capped and the valve in the on position, allowing mixing of hot and cold. 

Or could also be a diptube in the heater issue, check faucet areators for white chunks.


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## beachplumber (Feb 7, 2010)

^^^what they said
recirc line?


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## Mississippiplum (Sep 30, 2011)

Any pressure fluctuations, low pressure one minute high the other minute-visa/versa? If so it is a problem with the well system.

sent from the jobsite porta-potty


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## Michaelcookplum (May 1, 2011)

Sounds like a cartridge issue. I install over 200 moen posi temps a year. Run into this scenario about once a year. Start by checking the basement valve to make sure it's off. If it is replace upstairs cartridge. Something could be clogging it from when they installed the basest valve


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## 89plumbum (May 14, 2011)

Qball415 said:


> Moen.....Cartridge!


Or lines looped together somewhere.


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## azmike (Feb 3, 2010)

With pressure balanced carts if there isnt pressure to both sides h/c they wont work and you wont get water. It could be the the cartrige being that its moen never did like them and they are a ***** to remove!


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## Michaelcookplum (May 1, 2011)

azmike said:


> With pressure balanced carts if there isnt pressure to both sides h/c they wont work and you wont get water. It could be the the cartrige being that its moen never did like them and they are a ***** to remove!


They are actually very very very easy to remove


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## U666A (Dec 11, 2010)

Michaelcookplum said:


> They are actually very very very easy to remove


Couldnt agree more...

The following user(s) wishes to thank U666A for this useful post: Mississippiplum, Plumber71, DesertOkie


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## Plumbergeek (Aug 16, 2010)

Michaelcookplum said:


> They are actually very very very easy to remove


Especially when you have this:


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## azmike (Feb 3, 2010)

Got one of those handy dandy pullers I was refering to the way the seals are attached to side of the cartridge!


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## drain surgeon (Jun 17, 2010)

gitnerdun may be on to something. I had the same thing happen on a remod. The shower had been caped off but the valve was in the open possision and caused spikes of cold water in the other shower.


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## Keefer w (Jan 26, 2012)

Check to see if they have balancing spool. Had one that froze up, lube and persuasion not help. Moen sent one to ho free. Was brownie points to go with other work I sold


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## Gaines21 (Feb 12, 2012)

this is something i have never ever read.very detailed analysis.


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## bizzybeeplumbin (Jul 19, 2011)

drain surgeon said:


> gitnerdun may be on to something. I had the same thing happen on a remod. The shower had been caped off but the valve was in the open possision and caused spikes of cold water in the other shower.



I had this happen once, I installed a tankless on a remodel another plumber did, when I got all packed up, the customer said he noticed a huge temp issue at his bathroom sink. I checked the unfinished bathroom and found a wall mount faucet body, hot and cold on, but the spout was plugged until the tile was done. closed the hot side of the 2 handle valve and everything was perfect.

Up until I found this faucet tho, I was about ready to start tracing copper lines to see if one was connected to another somewhere.


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