From Moen's trouble shooting discussion:
Debris or an obstruction in the balancing spool is causing it not to move freely within its housing. In some models, a lack of pressure feeding the hot and cold will be the cause. The valve also may need to be calibrated.
First, verify the hot water system in the home is operational.
Second, it is essential to identify the model of your faucet. Please view our Find Your Product
section to determine your model.
For Posi-Temp models:
The 1222 cartridge would need to be replaced and the valve body would need to be flushed and cleaned.
For Moentrol models:
Inspect the 1423 balancing spool. This will appear on the front of the valve body, either to the right or above the cartridge. It will look similar to a large flat head screw, and it will be brass in color. A large flat-bladed screwdriver can be used to unscrew the balancing spool from the valve. There will be a spool inside this piece, and it needs to move freely inside of its shell. If the spool does not move freely, then the 1423 balancing spool will need to be replaced.
For ¾" ExactTemp models:
Note: For ½" ExactTemp valves refer to original service manual
- Verify the shut off valves (check stop kit) are in the open position. This will be a screw in the center of the check stop kit. These should be unscrewed counter-clockwise.
- Check to see if the hot and cold lines are reversed. If the supply lines are accessible, feel the temperature of the pipes. The cold supply must be connected to the cold (right) side of the valve, and the hot supply must be connected to the hot (left) side of the valve. If this is the case, the valve will need to be reinstalled. Note: The cartridge cannot be reversed to correct this issue.
- The cartridge would need to be calibrated. Instructions on calibration can be obtained via the ExactTemp Service Manual in our Literature Center.
When calibrated properly, the ExactTemp valve should provide a range of temperature of 80 to 120 degrees Fahrenheit.
For ioDigital models:
For standard valve models:
- Verify the shut off valves are in the open position. These will vary depending on your ioDigital model.
- Remove the valve inlet screens and inspect for any debris. The water supply will need to be shut off, and then the black nut on the inlets can be unscrewed to remove the inlet screens. Rinse off any debris that may be on these screens and reinstall.
- Check to see if there are shut off valves installed with the unit. Verify these valves are opened all the way.
- The cartridge (for one-handle faucets) or cartridges (for two-handle faucets) would need to be removed (or replaced) and the valve body would need to be flushed and cleaned.