MOEN POSI TEMP or TANK - please help

[MRD]

My name is Mike and this is my first post.
I'm in Vancouver BC.
I have a suite below and it was vacant for 2.5 months. No renter ever mentioned a problem about this.

The new renter claims the hot water runs out quickly. Even at 4am, he says the tub only gets 5 inches full before it starts getting cooler. At 4am, I assume the hot water tank is totally full. I don't take baths, so is this typical behaviour?

When the faucet is first on it is very hot.

I already adjusted the scolding limiter so it is completely hot but that apparently didn't solve it.

Would this have anything to do with the moen valve cartridge?
It was only put in 3 years ago and no other tenant mentioned this problem.
How would the cartridge either be letting some cold mix in or ?

I have also read it could be the dip tube on the hot water heater. The tank is 20 years old but we could usually get at least 2 showers (20 mins) before I notice it is only warm not hot.

I don't have the model number but I have the installation manual and it lists several models.
L82382, L82383, TL2301…


Any help or guidance appreciated.

 

[havasu]

The tank is 20 years old ...

Welcome Mike! I'm afraid you've possibly answered your own question. You may buy some time by draining your tank to remove the sediment and replacing the heating elements and dip tubes, but remember, most only last 8-12 years.

 

[MRD]

Damn,

so nothing to do with the moen valve… too bad. Is it worth a shot trying to change the cartridge? If the scold limiter is fully off there's no way cold water would be mixing with the hot right?

Apparently this model has a "Posi-Temp pressure–balancing valve maintains water pressure (straight off of the hd website)" could that be malfunctioning?



Thanks for the help

 

[havasu]

Anything is possible. Are you having this problem at other faucets around the house?

 

[MRD]

I'll give it a test today to try it out. maybe I can get my hands on a few thermometers to actually get a reading.

I haven't noticed except for by the end of my shower it gets just luke warm if the control is fully on hot ( approximately 20-25 minutes total shower time for the two of us).

 

[MRD]

Opened up the aerators on some of the sinks.

Got a piece of metal in one and a 3/4 in grey plastic sliver in the other.
Could be parts of the dip tube?

Thanks again

 

[havasu]

Usually a dip tube will dissolve, but small chunks of the zinc might possibly wash downstream. As far as the plastic, this was probably residual from the plumbing or faucet installation.

 

[phishfood]

I would expect a dip tube problem to show up rather quickly in the hot water usage cycle , so I don't think that is your problem. At 20 years old, your tank is overdue for replacement, and that would remove a lot of possibilities.