Honeywell V4073A1039/U 22 mm Mid Position Valve

Product Information

These valves have compression pipe connections, though Honeywell make motorised valves with threaded connections too. How motorised valves are used Where two 2-port motorised valves are fitted (one for the heating circuit and one for the hot water cylinder circuit) the fault may be disguised. Even though one valve only partly opens itself and is unable to fire the boiler, the valve on the other circuit can open fully and fire the boiler. The pump then pushes heated boiler water through both the open valve and the partially open valve. You should be able to feel a bit of spring resistance, right at the far end (Man Open end) of the slot. The rubber ball sits against the circular port (right side in photo), closing it off. We’re told that the ball touches one edge of the circular port first, causing the ball to rotate slightly on its spindle. This regular slight rotation evens out distortions in the ball. A little piece of elegant design work by Honeywell!

Seized motorised valve spindle in an old Satchwell Sunvic 2-port motorised valve. The water leakage has caused white oxides to form round the brass spindle, making it too stiff to turn

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The Honeywell valves have a D-shaped top to the spindle but you can also use a spanner on this. If you do this, you must use very little force as it is very easy to shear a spindle or damage the valve internally.

Replacement Honeywell SYNCHRON motors are available but are a bit more expensive. For a long time we’ve used the standard SYNCHRON motors as replacements, with very few problems.Sometimes if I bang the valve with my hand sometimes CH and HW start to work after some gurgling noises The Honeywell V4073A is a spring-return valve. Port A or port B can be closed by a rubber ball, though never both at the same time. The rubber ball is moved between ports A and B by an actuator shaft or spindle which is driven by the powerhead. The inlet port AB can never be closed; the ball only moves between port A and port B. Inside a Honeywell V4073A 3-port motorised valve showing the rubber ball which closes one or other port, never both.

When all electrical power to the heating controls is switched off, the spring pulls the ball across to close port A, leaving port B open. This is the relaxed state or de-energised state of the valve. It is also sometimes called the Normal state. V4043H1080 is a 2 port, 1” BSP Female threaded, 6-wire, normally-closed zone valve with an auxiliary end switchIf it’s the other way round, and the 2-port valve controlling the hot water circuit is failing, it may be less obvious. The heating circuit valve may be open for long periods telling the boiler to fire. If the hot water valve is partially open, you may not run out of hot water. Crimps are metal tubes within plastic insulation, which are flattened using pliers to trap two wires, joining them electrically. These crimps can sometimes be re-opened by using pliers to squeeze together the edges of the flattened tube. This can be done with the plastic in place. If successful it frees the two wires. The plastic insulation may break, in which case the crimp is discarded. There is, however, more information the lever can give us if we know what we’re looking for. The lever pushes the valve open against the return spring. The valve does not pull the lever over towards the open end as the valve opens. Is the manual lever directly connected to the spindle? If so if I move it to open position then water must flow and therefore the boiler should fire up as hot water leaves it. When using a 3-port valve, the control system may be known as a Sundial Y Plan system or a Honeywell Y Plan system.

I tried out of interest to see what would happen during this state, if I set the controller to switch on heating. Nothing happened. If Hot Water is then satisfied (either by the programmer or cylinder stat), the grey wire is energised. As there is still a demand for Heating, the valve will motor to the Heating Only position (port A open; port B closed) and switch a 230V supply onto the orange wire, to power the boiler. A Switchmaster Midi 3-port valve body with a seized spindle. This motorised valve was also rusting through round the screw in the picture Honeywell powerhead (actuator) jams? The Honeywell mid-position motorised valve has three ports in a T configuration. Water enters via port AB. Water leaves by either port A or port B or by both at the same time. Port A is normally connected to the radiator circuit and Port B to the cylinder coil (to heat hot water). The circulating pump is usually connected to feed water from the boiler into port AB.Slide the blunt end of the motor sideways until the flange comes out from the tab holding it down. This can be a bit of a fiddle. The motor then comes free of the valve, held only by the two wires which connect it electrically. These two wires may be blue (in a Honeywell original Synchron motor) or orange (most replacement Synchron motors). As we’ve said above, Honeywell make a large range of motorised valves. The Normal state of a valve is the de-energised state. This is the state when no electrical power is being used by the valve motor. Whereas the internal electrics of the 2-port valve are quite simple, the internal electrical controls of the V4073A mid-position valve are more complex.