When Heating is also called for, the white wire is energised and the valve will motor to, and stop in, a mid-position. Power for the boiler is still supplied directly from the cylinder thermostat. The orange valve wire may have a potential of 230V but this is coming from the cylinder stat (to which the orange wire is also connected) and not from the circuitry of the valve. The V4043B valves are uncommon and likely to be found in solid fuel systems. These valves fail-safe in the open position in the event of a power failure or valve motor failure. V4043H1106 is a 2 port, 28mm compression, 6-wire, normally-closed zone valve with an auxiliary end switch The Honeywell V4043H1106 28mm 2-port zone valve has 6 wires. Five of these wires are the same as 22mm 2-port valve.Green/yellow is Earth, blue is Neutral, brown is Live (or Line) to the motor, grey and orange are connected to the end switch and form part of a separate circuit.

Honeywell Home 22mm 2 Port Motorised Valve (V4043H1056/U) - CEF

Both of these genuine SYNCHRON motors work in Honeywell motorised valves. The motors SYNCHRON make specifically for Honeywell come with two blue wires If you turn the hot water on and the programmer instructs the valve to open, then you should feel the lever will move freely (try to move it before you turn the programmer to the on position - you will feel some resistance, to compare the difference). If you know how to work safely with mains voltage electricity, the valve motor can be tested with a multimeter. With the mains electrical supply turned off and isolated, the resistance across the two motor wires (either both blue or both orange) can be tested. To test correctly, at least one of the two motor wires must be disconnected from the heating wiring circuit. 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. On older style valves pre-1985, which do not have the replaceable head feature, the adaptor plate assembly can be used to upgrade the valves, to allow the replaceable powerhead to be used.”

Product Specification

However, if you need to replace the motor it may be easier to remove the powerhead so you can work on it in the open. Remember, on early Honeywell motorised valves (pre-1985) you can’t remove the powerhead without draining down first! 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. 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. This banging occurs due to air in the pipes. If I goto the loft and bleed the top-most valve the banging will go away. I can then use the HW again but I end up having the same problem."

Honeywell Home 40003916-001 2 Port V4043H Replacement Honeywell Home 40003916-001 2 Port V4043H Replacement

Nearly all Honeywell valves have a powerhead (also called an actuator) which can be separated from the valve body. The valve body is the brass casting which is bolted into the pipework. If the property uses a combi boiler (rather than a heat-only boiler) the boiler will usually contain a diverter valve. In small properties there may be no other motorised valves. I have a Honeywell 2 port valve (which looks like a silver box) which is situated close to my boiler. This valve has a small lever at the bottom of it. What I want to know is does this lever move when the valve is in operation? Im sure it used to but at the moment it does not.... The V4043B normally open model is particularly applicable to control of solid fuel systems, since it will always fail-safe in the event of a power failure) We find it is normally about 2.1kΩ (2100 ohms) if the motor is cold and up to 2.4kΩ (2400 ohms) if the motor is quite warm. I think that a reading anywhere between 2.0kΩ (2000 ohms) and 2.5kΩ (2500 ohms) suggests that the motor windings are probably OK. If the reading is many times higher than that, or it is open circuit, the motor has failed.

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. Honeywell V4043H1056 22mm 2-port zone valves have five wires: green/yellow is Earth, blue is Neutral, brown is Live (or Line) to the motor, grey and orange are connected to the end switch and form part of a separate circuit.

Honeywell Motorised Valve Faults - Free Heating Advice Honeywell Motorised Valve Faults - Free Heating Advice

When using a 3-port valve, the control system may be known as a Sundial Y Plan system or a Honeywell Y Plan system. Motorised valves are often fitted in tight spaces with limited visibility so note the orientation of the powerhead. On modern Honeywell valves, if the powerhead fails it can be removed from the valve body without draining down. However,be warned!With very old Honeywell motorised valves the powerhead could not be removed without draining the water first. There are lots of poor quality synchronous motors out there. If the motor cap says “Synchronous” rather than “SYNCHRON ®” it may cost less than half but you’ll probably be changing it again before long! Move the valve’s manual lever to the manually open position. (Push it towards the MAN OPEN end of the slot and lift while releasing it, so it settles into the hook at the top of the slot.)It will make it easier when re-fitting it (just remember which end the flex was connected or take a picture on your phone). The powerhead can only fit one way round onto the valve body but if space is tight that might not be obvious. V4043C1156 is a 2 port, ½” BSP Female threaded, 3-wire, normally-closed zone valve but has no end switch In medium sized or larger properties, using a combi boiler, there may be an additional zone valve external to the boiler which allows the heating to be split into two zones. If the valve motor fails, the motorised valve will not open. The valve will not then close the end switch and so will not complete the auxiliary circuit. The boiler will not fire (with no open pipe circuit to dissipate the heat), unless another motorised valve opens another pipe circuit and calls the boiler into action. This prevents the boiler firing and the pump running when there is no water circuit open.

Valve 95C-10819 - V4043H Motorised Zone Valve

Occasionally we come across a Honeywell motorised valve where the powerhead jams but the spindle (actuator shaft) is still free. Where this happens it is usually with the valve jammed open. If all the power to the central heating system is turned off, and the manual lever is still loose across the whole slot, the mechanism may be jammed. A programmer and cylinder thermostat (stat) are used to control the times when the hot water is heated and to control the maximum temperature of the stored hot water.I'm assuming that you've got no hot water due to the overheat malfunction - in which case there's nothing to stop you hooking the valve open permanently if this resolves the banging (and simultaneously getting you some hot water) until we determine why the valve isn't opening. IF it is a faulty valve, these aren't difficult to replace. These valves have compression pipe connections, though Honeywell make motorised valves with threaded connections too. How motorised valves are used I suppose my only question now is, after following your instructions how will I know if the valve is broken / needs replacing? In normal operation, with a heat-only boiler, central heating water is heated in the boiler and then pumped round the system by a circulating pump. Motorised valves are used to split or divert the flow. The heated water can either be sent to the radiators (or underfloor heating) or to the cylinder coil to heat the domestic hot tap water. The cooled circulating water is then returned to the boiler to be heated again. 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.