Thermostatic mixing valve help

[dmichel]

Hi everyone. Thanks for any help in advance. I moved into my house about a year and everything worked fine. The last couple of days I've been unable to get really hot water in our master bath. The shower, sink, and tub all get warm but not hot. Warm enough to shower but just barely. The hot water tank is fine as the rest of the house has properly hot water. I suspect a thermostatic mixing valve, but the problem is there isn't one in the mechanical room near the tank, and everything else in the house is drywalled so I fear there my be one buried in a wall or under a floor. But this seems stupid and I'd have thought against code. Anybody have any suggestions of what else it could be or where to look if I'm on the right track.

Cheers

 

[Mr_David]

what kind of shower valve do you have. Could be the mixer in that.
I would repair that first if you can't find a common mixer for the bathroom. Could be cold water is passing through valve even when iy is closed.

 

[dmichel]

what kind of shower valve do you have. Could be the mixer in that.
I would repair that first if you can't find a common mixer for the bathroom. Could be cold water is passing through valve even when iy is closed.

Not sure the brand but it's fairly nice with 2 body sprays Integrated. Is that a common practice with all washroom water supplies going through a shower valve?

 

[dmichel]

what kind of shower valve do you have. Could be the mixer in that.
I would repair that first if you can't find a common mixer for the bathroom. Could be cold water is passing through valve even when iy is closed.

Figured out it's a delta monitor with sprays. I think it has a built in thermostatic mixer but the documentation isn't great.

 

[Mr_David]

Delta Monitors I believe are pressure balanced valves, Not thermostatic.
There is a difference.
The water supply to other fixture does not intentionally pass through the mixer valve but on occasion upon failure of inner seal may allow cold/hot to pass through the valve while it is in the closed position. Moen were notorious for this. Delta monitors ?? unknown if they do.

We used to check for this by shutting off the water supply to water heater.
if water is crossing over it will be evident when you turn on the hot water at a fixture. Should be getting no water from hot side. If you have a significant flow go listen to each fixture and see if you hear water passing though it.

 

[dmichel]

Delta Monitors I believe are pressure balanced valves, Not thermostatic.
There is a difference.
The water supply to other fixture does not intentionally pass through the mixer valve but on occasion upon failure of inner seal may allow cold/hot to pass through the valve while it is in the closed position. Moen were notorious for this. Delta monitors ?? unknown if they do.

We used to check for this by shutting off the water supply to water heater.
if water is crossing over it will be evident when you turn on the hot water at a fixture. Should be getting no water from hot side. If you have a significant flow go listen to each fixture and see if you hear water passing though it.

Reviving an older thread. I changed out the shower valve in December. The new cartridge fixed the problem. At least for a while. It's been about 3 months and the same problem has returned. I assume the repair cartridge has failed again but after 3 months seems excessively short. Anyone have any insight?

 

[ExtraMilePlumbing]

What’s the water pressure to the house? Also water quality(lot of chlorine)? How old is the water heater ? Do you flush it once a year? It could be a lot of sediment from the water heater clogging up that sensitive cartridge, also repeat the steps mr David suggested(this time it might be another single handle faucet)could also be the quality of cartridge , did you get it from manufacture and grease it up before you installed it

 

[dmichel]

What’s the water pressure to the house? Also water quality(lot of chlorine)? How old is the water heater ? Do you flush it once a year? It could be a lot of sediment from the water heater clogging up that sensitive cartridge, also repeat the steps mr David suggested(this time it might be another single handle faucet)could also be the quality of cartridge , did you get it from manufacture and grease it up before you installed it

Water pressure is good but I don't know the psi. We are on a well with a submersible pump. No chlorine and a few year old water heater. Haven't flushed it, maybe that's the next step. I tore down the old cartridge and there was a bit of rust discoloration but nothing obviously clogging the pressure balance valve.

 

[ExtraMilePlumbing]

Just replace the cartridge with a manufacture one , also make sure it’s not another single handle valve crossing over, they sell water gauges in any hardware store

 

[Matt30]

Long time no see extra mile!

 

[ExtraMilePlumbing]

Long time no see extra mile!

I know, I’m glad to be back and with more experience to help others, 2 more years till I open my own doors can’t wait.