Running out of Cold Water in 4 minutes -Moen Posi-Temp Valve

[DMM8788]

Recently had two showers remodeled in house. Purchased Moen Commercial Posi-temp Pressure Balancing Shower valve w stops 1/2 inch sweet c connections & 1/4 turn stops and Moen Shower Brass 3-function shower transfer valve. Once the showers were finished we are having an issue with the waster temp. We run out of cold water in 4 minutes time and it starts going warm (water temp will start out at 70 degrees and within 4 minutes jumps to 81 degrees when positioned only on cold water. We have had the cartridge replaced 2 times in each shower because Moen said we should, but it has not made a difference.

When the plumber first started on the bathroom remodel he did see a crossover in the first shower and fixed it. However, once the showers were finished and we tried replacing the two cartridges he put the crossover back to the original way. It actually improved some in the shower the crossover is located in (cold water might last a minute or two longer but still runs out) but worse in the other shower. Never had an issue with the water before. The water use to be be very cold before the remodel. Any ideas what might be wrong or what we should do next? Thank you

 

[Reach4]

Can you feel the output pipe on the WH during problems? Those infrared thermometers can measure the pipe temperature if the pipe is not shiny.

 

[Sponsor]

 

[WorthFlorida]

I always eliminate and isolate with troubleshooting. Any recirculating system?
Do you have one of those kitchen faucets with the auto on sensor? With the faucet level always open, a cross mix might occur. Do other fixtures have the same problem? Two showers doing the same thing is strange and maybe something else in the home.

1) At every sink and washing machine, close all stop valves and one shower. Then check the water temp. If it stays normal, open one stop valve at a time.

2) If not change from the first test, Close the stops at the shower and remove the cartridge. Slowly open one of the stops and let the water run (out the valve body) to be sure the problem is not before the cartridge. Then close the stop and repeat with the other one.

3) Do the same with the crossover, remove the cartridge and with the main valve body cartridge reinserted, do the same test to prove the cross over is not the problem.

Sweated copper connections are the best, however, small bits of solder can let loose inside the pipe and jamb things up. You may need to remove the stops and flush out the valve bodies.

Terry Love posted a problem he had where a solder drip landed right inside the valve body and plug up the port to the shower head. When I moved into a new house, I didn't have the filters on the fill hose for the washing machine. It ruin the fill valve from bits of solder.

 

[DMM8788]

Can you feel the output pipe on the WH during problems? Those infrared thermometers can measure the pipe temperature if the pipe is not shiny.

I ran the shower water temp started at 71 degrees. Ran the shower for 15 minutes. I checked the pipes on WH. Cold pipe was room temp I would say. When I went back up to turn off shower the water temp was now 92degrees. It it just on the cold water but temp keeps increasing.

 

[DMM8788]

I always eliminate and isolate with troubleshooting. Any recirculating system?
Do you have one of those kitchen faucets with the auto on sensor? With the faucet level always open, a cross mix might occur. Do other fixtures have the same problem? Two showers doing the same thing is strange and maybe something else in the home.

1) At every sink and washing machine, close all stop valves and one shower. Then check the water temp. If it stays normal, open one stop valve at a time.

2) If not change from the first test, Close the stops at the shower and remove the cartridge. Slowly open one of the stops and let the water run (out the valve body) to be sure the problem is not before the cartridge. Then close the stop and repeat with the other one.

3) Do the same with the crossover, remove the cartridge and with the main valve body cartridge reinserted, do the same test to prove the cross over is not the problem.

Sweated copper connections are the best, however, small bits of solder can let loose inside the pipe and jamb things up. You may need to remove the stops and flush out the valve bodies.

Terry Love posted a problem he had where a solder drip landed right inside the valve body and plug up the port to the shower head. When I moved into a new house, I didn't have the filters on the fill hose for the washing machine. It ruin the fill valve from bits of solder.

Yes both showers have an issue with losing cold water. One shower it stays colder longer and the goes warm (this shower’s water temp doesn’t increase as much as the main shower water temp once you lose cold water.

We do not any any sensor faucets.
We did shut off hot water valve to washing machine. We noticed it made the kitchen sink hot water to increase in temp when it was off. When we opened the washer hot water again kitchen sink went back to normal hot water.

 

[Reach4]

I ran the shower water temp started at 71 degrees. Ran the shower for 15 minutes. I checked the pipes on WH. Cold pipe was room temp I would say. When I went back up to turn off shower the water temp was now 92degrees. It it just on the cold water but temp keeps increasing.

I was actually thinking of checking the temperature of the the hot pipe (out of the WH).

 

[WorthFlorida]

This is making no sense. Normal hot and increase in hot temp is the the real temperature from the water heater, not the normal temp. Shut off both the hot and cold at the washing machine. There is a mixing going on somewhere but usually it the hot that cools down. When water is flowing, cold water has more pressure than the hot side, therefore, the cold mixes with the hot and the hot cools down.

Does this happen at the sinks? If not, something was done wrong at the shower valve bodies.

With hot only running at the showers, does the temperature stay level after hot water reaches the fixture?

What heats the water? Furnace, gas water heater, electric HW, tankless? A picture can help.

Are you sure the cartridges are in correctly? The can be inserted 180 degrees if two valve bodies are back to back. Eliminates some plumbing configuration. The hot water and cold can be install opposite of normal. Cold on left, hot on right.

 

[Jeff H Young]

if the cartridge was reversed it would never allow full cold just warm water after the hot got there from water heater it would get a mix of cold and some hot but wouldnt be full cold

 

[DMM8788]

if the cartridge was reversed it would never allow full cold just warm water after the hot got there from water heater it would get a mix of cold and some hot but wouldnt be full cold

The two showers new valve systems were installed by two different plumbers. When I contacted Moen about the issue they sent me new cartridges to be installed. We have had the plumber replace them in both showers twice. It’s just really strange we had no issues with the hot & cold water until we remodeled the showers. Very frustrating to say the least.

 

[DMM8788]

This is making no sense. Normal hot and increase in hot temp is the the real temperature from the water heater, not the normal temp. Shut off both the hot and cold at the washing machine. There is a mixing going on somewhere but usually it the hot that cools down. When water is flowing, cold water has more pressure than the hot side, therefore, the cold mixes with the hot and the hot cools down.

Does this happen at the sinks? If not, something was done wrong at the shower valve bodies.

With hot only running at the showers, does the temperature stay level after hot water reaches the fixture?

What heats the water? Furnace, gas water heater, electric HW, tankless? A picture can help.

Are you sure the cartridges are in correctly? The can be inserted 180 degrees if two valve bodies are back to back. Eliminates some plumbing configuration. The hot water and cold can be install opposite of normal. Cold on left, hot on right.

No only happens in showers. Gas water heater.

 

[WorthFlorida]

Fully to the right, clockwise, is cold. Counter clock wise is hot. When the cold water get warm, moving the faucet all the way to hot, does the water get hotter?

 

[Jeff H Young]

I figured reversed cartridge was obvious but might not be just open it to where water starts to come out this should be the coldest the farther you turn it the hotter it gets . handle only turns in one direction from off

 

[GReynolds929]

Do you have pictures of the rough in piping before it was covered up? There are some specific things required to be done with this transfer valve. If it is not installed properly you can get these symptoms happening. it clearly is not a cartridge issue.

 

[Jeff H Young]

He might have fixed it and forgot to get back and share problem or thank anyone.

 

[WorthFlorida]

One of thousands of post that in a sense had not been closed out.

 

[DMM8788]

Do you have pictures of the rough in piping before it was covered up? There are some specific things required to be done with this transfer valve. If it is not installed properly you can get these symptoms happening. it clearly is not a cartridge issue.

No unfortunately I don’t have a pic of the pipping before it was covered up.

 

[DMM8788]

He might have fixed it and forgot to get back and share problem or thank anyone.

No still having the problem.

 

[GReynolds929]

Do you know if check valves were installed on the hot and cold supply lines to the positemp valve? Page 4 of the transfer valve instructions says that is necessary.

you say the plumber found and fixed a crossover, can you provide more info on that.