After researching mixing valve problems on the web I had the cartridge
replaced in the Moen single handle shower valve to increase hot
The hot water is known to be available by the sink next to shower
where it is very hot.
The new cartridge did not produce any more hot temperature than the
old (2.5 years) one.
Seeking a solution I removed the stop for the rotation to see if more
hot water could be found. There was a burst of very hot water for a
brief (.5sec) without changing handle and then a return to just warm
This suggested that a thermostat was kicking in to prevent scalding
when water is too hot. So I lowered the temperature from the tankless
heater but it did not improve the condition. The research said these
thermostats sometimes use wax pellets that control temps.
Question..is the thermostat located in the cartridge? If not where
would it be?
Question what other possible cause is preventing hot water reach
It does sound like you have one of those safety valves that actively
restricts the hot water. All mine simply have adjustable stops and I
have adjusted them to be pretty hot. I saw a number of those safety
ones on clearance at lowes the other day, they must not be very
popular. A restriction in the piping is very unlikely unless you have
a really old house. Cant you see any sort of model number or part
number on the valve body? That would allow you to research it
further. Otherwise I don't see any way to know for certain except to
replace the entire valve.
First the problem is probably not your valve , but your plumbing .
The valve will not make water hotter then what it is coming into the
valve . The only thing you can control is the pressure balance and
the Temp limit control which involves a couple of plastic rings under
the handle which are probably set wrong . Suggest you read this
section of the directions with the tap , also suggest you stop
looking for a thermostat on the tap as there is not one . Only a
limiter to control how far you can turn the handle to the hot side ,
as to not scald kids . Also check your pressure balance if it
rattles it is good if not get it replaced .
Number on black part of assembly is 109113 and was installed two and a
half years ago.
Adjusted plastic rings to max without change of temp.
How is pressure balance checked? What rattles?
The handle has to be turned counter clockwise from 12 to 3(max) to get
hot water or warm water.
That seems like the hot has to compete with an awful lot of cold
water. I live in Florida and the water is
not very cold.
Your help is appreciated.
You didn't tell us it had deteriorated over a period of time. That
model doesn't appear to include the scald protection but does have
some sort of pressure compenation design. Maybe that's what was
Replacement cartridge did not solve hot water problem. I have tried
changing temperature setting on the Titan tankless SCR2 higher and
lower with no change to temp. I turned the valve to max hot and
adjusted the main inlet valve to minimum with no luck either.
Did I mention the pressure is definitely less on hot setting?
I would like to avoid tearing into walls to get to the galvinized
pipes. There is one inline shut-off on exit side of heater. Reducing
that did not change anything.
At whits end....
Can you turn the cold supply off and leave the hot on? If so do that
and turn the hot water on with the cartridge removed. The water will
spray out of the opening where the cartridge goes. See if it gets hot
I doubt you have galvinized pipes. How old is the house?
I replaced the shower head with the original water saving type and my
hot water problem is solved.
I'm embarrassed to not have thought of this before even at the urging
of halerb to check it.
Thanks to all who considered the problem and gave advice.
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