Installation
MF2904/IR
Bradley Corporation
• 215-752 Rev. U; EN 08-023
9/25/08
9
Before attempting to troubleshoot the valve or disassemble the components, check for the following conditions:
• If stop/check valves are used, make sure that they are fully open.
• Make sure that the hot and cold inlet pipes are connected properly, and that there are no cross-connections or
leaking stop/check valves.
• Check the hot water heater output to make sure that it is at least 20° F above the set temperature.
Thermostatic Mixing Valve Troubleshooting
Be sure to close the appropriate shut-off valves prior to disassembly of the valve and reopen the valves after inspection
and repair is complete.
Problem
Cause
Solution
External leaks in the system.
O-rings have been
damaged.
Replace O-rings where necessary. Contact your Bradley
representative to order Repair Kit (part number S65-259).
Improper water temperature or
temperature fluctuation.
Thermostat is slowly failing
or not working at all.
Check the thermostat for proper operation.
1. At room temperature (80° F or less) remove the cap and
thermostat.
2. Place the thermostat into a container with 115° F water. The
pushrod should pop out of the thermostat approximately 1/10".
3. If thermostat pushrod does not pop out, the thermostat must
be replaced. Contact your Bradley representative to order
Repair Kit (part number S65-259).
Valve temperature is not
properly set
Adjust the temperature.
Using a blade screwdriver, turn the adjustment stem
counterclockwise to increase the temperature or clockwise to
decrease the temperature.
Limited water flow.
Dirt and debris have built
up in the valve or strainer.
1. Check to make sure both hot and cold supplies are connected
to the Vernatherm mixing valve and that they have water flow.
2. Remove and clean the strainer. If strainer needs to be
replaced, Contact your Bradley representative to order Bradley
part no. 173-028.
3. Check the piston for smooth movement:
A. Remove the valve’s cap and thermostat.
B. Push down on the piston with your finger (the piston
should move freely). If the movement is not as it should be,
the piston needs to be cleaned. Follow the method outlined
below for cleaning the piston and valve body:
• Remove the thermostat.
• Lift the piston out with a needle-nose pliers and remove
the spring.
• Any cleaner suitable for brass and stainless steel may
be used (if cleaning with suitable cleaner is not sufficient
to remove debris, a 400-grit sandpaper may be used to
polish and hone the piston and valve body).
• Snap the spring into the piston (it will detent);
reassemble into the valve body. Retest the piston.
C. If, after a thorough cleaning, the piston does not move
freely, the piston must be replaced. Contact your Bradley
representative to order Repair Kit (part number S65-259).
