Honeywell T104F - Manual (Page 5)

5 62-3047
Troubleshooting
Sympton Possible Cause Solution
All sections of
the radiator are
not heating. 1. Many radiators are over-sized and all
sections are not required to heat up to
maintain the set room temperature.
1. System is operating properly.
Underheating. 1. Sensor is in the wrong location. 1. Change the sensor location or change the control
type. See installation instructions.
2. Excess capillary tube is coiled above or
too near the heat source.
2. Coil excess capillary tube below or away from the
heat source.
3. Flow through the valve is in the wrong
direction.
3. Check the arrow on the valve body. It should be in
the direction of the flow. Change the valve direction
or flow direction.
4. Inadequate system temperature or
pressure.
4. Check the operating and limiting controls on the
boiler. Check the circulating pump and isolating
valves.
5. Steam traps are defective. 5. Repair or replace the traps.
6. Air lock in the hot water system. 6. Open the valve fully to allow air to pass. Install
vents.
7. Scale or debris is blocking flow. 7. Flush the system. Do not use oil base additives.
Clean strainer insert in steam applications.
8. Heating cabinet dampers are closed. 8. Open or remove the dampers.
Overheating. 1. Sensor is in the wrong location. 1. Change the sensor location or change the control
type.
2. Control is not properly installed. 2. Set the bosses in the grooves and tighten the
knurled ring to the valve body.
3. Capillary tube is broken, kinked, or
bent sharply.
3. Replace the control.
4. Dirt or scale is under the seat,
preventing tight shutoff.
4. Remove the control from the valve body, allowing
the valve to open fully and flush away scale and
debris. Reinstall the control and turn fully clock-
wise. If the valve does not fully close, remove con-
trol and cartridge using a cartridge changer tool or
service socket (isolate valve from system if not
using changer tool). Inspect and clean valve seat
area and disc. Always use a strainer insert in steam
applications.
5. Flow through the valve is in the wrong
direction, damaging the valve seat.
5. Check the arrow on the valve body. It should be in
the direction of the flow. Change the valve direction
or flow direction. Remove the valve cartridge and
inspect for damage to the seat disk.
6. Steam traps are defective. 6. Repair or replace the traps.
7. Excessive differential pressure is
forcing the valve open (hot water
systems).
7. Install a differential pressure regulator (D146A) to
maintain less than 117 kPa (17 psi) differential
between supply and return pipes.
Chattering or
knocking. 1. Flow through the valve is in the wrong
direction.
1. Check the arrow on the valve body. It should be in
the direction of the flow. Change the valve direction
or flow direction.
2. Vacuum in the system. 2. For steam—check traps and vents. For hot water—
check expansion tank operation and location.
3. Excessive differential pressure. 3. Install a differential pressure regulator (D146A) to
maintain less than 117 kPa (17 psi) differential
between supply and return pipes.
4. Binding of piping. 4. Make sure there is adequate space for piping.