Can I Repair a Honeywell Zone Valve?

Can I Repair A Honeywell Zone Valve? The task is not that difficult. Most mechanically minded homeowners will have the tools on hand to perform this job.

Some Basic Information

Honeywell zone valves are electrically operated. There primary function is to open and close on a temperature rise, or fall, from their respective thermostat. Thermostats are remotely located within the area they are controlling.

This type of valve has a small rubber ball within the piping. The ball actually rotates on an offset shaft and blocks the passage. When the circuit calls, the ball rotates out of the way, allowing the flow of liquid.

Using this type of valve allows the control of multiple areas, or zones. Each zone will have a Honeywell, or equivalent zone valve. These zone valves are prone to failure within a few years time. Repairing your zone valve yourself can save hundreds of dollars on a service call.

Tools You’ll Need

Honeywell zone valves have an electric motor that is replaceable. To remove and replace this part, you will need a Phillips headed screwdriver for newer valves and a slotted head for older valves.

Some valves will use an Allen head bolt to hold the motor assembly in place. If this is the case on your Honeywell zone valve, then you will need the proper size Allen wrench.

To replace the mechanical section that sits behind the motor, you will need a proper sized socket or nut driver to remove the mounting bolts.

To replace the entire valve assembly, you will need soldering tools. The total replacement of this valve may require your system to be drained and then re purged after the repair. If you need an entirely new valve, a qualified heating serviceman is recommended.

Replacing Your Electrical Motor Assembly

Before beginning this job, the electrical power to the zone valve must be off. Find the circuit breaker that runs power to your heating system and shut it off. Then test for power at the zone valve and make sure it’s off.

Remove the main cover from your Honeywell zone valve. Normally they simply pull straight off. Inside you will see the motor that actuates the valve. This assembly is held to the brass body of the valve with two mounting bolts. One is on the top left corner and one is on the bottom right.

The bolt heads will be either a slotted screwdriver head, a Phillips screwdriver head, or an Allen wrench head bolt. Use the proper tool and remove the two bolts from the valve.

Once you have removed both bolts the assembly will pull straight out from the body of the valve. Use care not to break or remove any of the wires just yet. Allow the old motor to hang from it’s wiring while you install the new assembly.

Note the shaft that is protruding from the rear of the motor assembly. This shaft is about 3/8 of an inch by 1/8 of an inch steel, that inserts into the corresponding slot in the valve body. This shaft and slot, must be in the same position, relative to each other, as the new part is installed.

Once the new motor assembly is evenly seated, the two mounting bolts are alternately tightened until snug. If the valve doesn’t seem to be seating right, then you probably have the shaft misaligned and it must be turned to fit into the corresponding slot. Several attempts may be necessary to get this just right.

After your new part is installed we still have to swap the wiring. Your old valve should be hanging from the wires we are going to use.

Using the proper screwdriver, one wire at a time, transfer the low voltage wires to the new motor assembly. Doing this one wire at a time will help to get everything back on the right terminals.

When your wires are finished you can cover the unit and re power your heating system. Your new Honeywell zone valve motor should perform well for years to come.

Replacing the Mechanical Actuator Ball Assembly

Start this repair by performing the removal of the electrical motor assembly as explained above. Your actuator ball assembly is behind the motor. Removing this must be done first.

Next you must isolate the valve from the rest of the system by closing valves on both sides of the valve. Once the zone valve has been isolated, a drain point must be found within the isolated section to relieve the pressure.

If isolating your zone valve is not possible, then the entire system must be depressurized to perform this repair. This also means that the entire system will need to be purged of air after your repair is complete.

If you are not familiar with the principles behind removing air from a heating system, then this job should not be attempted and a qualified serviceman should be called.

Assuming that you can isolate your zone valve, locate the four mounting bolts that hold the actuator assembly to the brass valve body. There is one bolt in each corner of the back plate. Using the proper sized socket or nut driver remove all four bolts.

Your closure assembly will pull straight out. Install the new o-ring that came with your replacement part and then the new actuator assembly and alternately tighten the four mounting bolts.

Next, reinstall the electrical assembly as instructed above. Open the isolation valves and check for leaks. If none are present then you can install the cover and restart your system.

If the entire system was drained, then your heating will need to be purged of all the air we let in, before re firing any burners.

Once the system is purged and re fired, check the operation of your new zone valve repair. There is a manual lever on the bottom of this valve. When you push on this lever there will be restriction when the valve is closed.

Turn up the room thermostat. If the valve is functioning properly, this lever will move with no restriction as the valve opens. Your heating apparatus will be fired and the piping will begin to heat up.

If you have multiple zone valves, get ready to make this repair a few times. Honeywell zone valves that were installed at the same time, will often fail within months of each other.