You should be able to feel a bit of spring resistance, right at the far end (Man Open end) of the slot. 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.

Honeywell Home V4043H1056/U 2 Port Motorised Valve - Screwfix

A programmer and room thermostat (stat) are used to control heating times and room air temperatures. The programmer and room stat may be combined into a single programmable room stat. 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.” With modern boilers, the boiler sends a Live feed to the circulating pump which then pumps heated boiler water through the valve. It will go to the radiators or to the cylinder coil, depending on which valve was opened. With older boilers, the Live from the auxiliary circuit end switch goes directly to the pump at the same time as it goes to the boiler Switched Live. 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. 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.Both of these genuine SYNCHRON motors work in Honeywell motorised valves. The motors SYNCHRON make specifically for Honeywell come with two blue wires 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.

Honeywell Motorised Valves | Central Heating | Screwfix Honeywell Motorised Valves | Central Heating | Screwfix

Synchron valve motors can remain energised and hot for many hours a day, all through the winter. They may eventually fail. A failed Synchron valve motor will prevent a 2-port motorised valve from working. The valve won’t be driven open and the end switch will not be made (connected) so power will not be sent on to the boiler or pump. Only when both white and grey wires are energised (and the valve goes to the Heating Only position) can the orange wire get its 230V supply via the valve itself. (Remember, the orange wire can also get 230V from the cylinder stat if it is calling and a hot water program is on.) 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. V4043C1156 is a 2 port, ½” BSP Female threaded, 3-wire, normally-closed zone valve but has no end switchThis can cause the valve spindle to seize. It often becomes stiff to turn at first and the valve may give intermittent problems. Eventually, the spindle may become so stiff that the valve motor cannot turn it at all. Honeywell V4044C1288 22mm 3-port diverter valve. This valve is not a mid-position valve. It opens either Port A or Port B (usually heating and hot water). Apart from the few moments when it is switching between ports, Port A and Port B are not open together. Note that it is a 3-wire valve, not a 5-wire valve The Y Plan and S Plan names are more commonly used when other Honeywell controls are also used (programmer, room thermostat, cylinder thermostat and wiring centre). If fitted in a confined space, sufficient ventilation must be available to keep the valve within its ambient temperature range and access must be provided to remove the powerhead if necessary It may be easier to have the valve set in the manually open position using the manual lever. (See Honeywell Motorised Valve Manual Lever, below.)

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

The auxiliary circuit allows several 2-port motorised valves to be used to control separate zones without interacting electrically. Otherwise, if several zone valves were used without auxiliary circuits, and all were connected to the same pump so that the Live wire that opened each valve also fed the pump Live, there would be problems. Honeywell 2-port motorised zone valves (V4043H) are electrically quite simple. The powerhead contains the motor, which is used to drive the valve open, and an auxiliary switch or end switch. Honeywell 22mm zone valve operation (V4043H1056) Honeywell say that the manual lever located on the end of the powerhead is not a position indicator and should be used used for filling the system and for draining down only. 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! 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.That noise and that bump are diagnostic. They tell us that the valve has moved into the mid-position where both Heating and Hot Water ports are open. If you can make a Honeywell 3-port mid-position valve move into all three of those positions, the valve and controls appear to be wired correctly and the valve appears to be working normally. Honeywell V4073A1039 22mm 3-port mid-position motorised valve showing inlet port AB and outlet ports A and B. This valve can be open to either port A or port B, or to both ports at the same time If the powerhead was removed from the valve to make it easier to change the motor, it must now be re-attached to the valve. The power head cover can then be refitted and secured with the single screw. Make sure it sits squarely on the powerhead, with no wires pushing out from the sides.

Honeywell Home 2-Port Motorised Zone Valve 1 Inch BSP

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. When using a 3-port valve, the control system may be known as a Sundial Y Plan system or a Honeywell Y Plan system. V4043H1106 is a 2 port, 28mm compression, 6-wire, normally-closed zone valve with an auxiliary end switchHoneywell 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. V4043H1056 is a 2 port, 22mm compression, 5-wire, normally-closed zone valve with an auxiliary end switch The Honeywell V4073A 3-port valve has five wires. These are blue, green/yellow, white, grey and orange. Note that the grey and orange wires are used differently from the grey and orange wires of the 2-port valve! Inside a Honeywell V4073A 3-port motorised valve showing the rubber ball which closes one or other port, never both. V4043H1080 is a 2 port, 1” BSP Female threaded, 6-wire, normally-closed zone valve with an auxiliary end switch