FAQs
The blue wire is the Neutral, N. The green/yellow wire is the Earth wire, E. The white wire is connected to the wire from the room thermostat which calls for heating (radiators or underfloor). The grey wire is used to drive the valve to the Water Off position, in which only the heating port A is open; it closes port B.
What are the five wires on a motorised valve for? ›
Electrically, the valve has 5 wires:
- Green/Yellow, Earth - connected to the metal body of the valve.
- Blue, Neutral - internally connected to the neutral side of the motor.
- Brown, Live in - Activates the motor inside the valve.
- Grey - Connected to one side of a switch inside the valve.
The brown is a switched live to the motor and the grey is a permanent live to the micro-switch which then energises the orange wire to the boiler - which must only operate once the valve has been opened.
What wire color goes to what terminal in a thermostat? ›
Blue or Black (C): The Unsung Hero
| Wire Color | Terminal | Function |
|---|
| White (W) | Heat | Heating system activation |
| Yellow (Y) | Cool | Cooling system activation |
| Orange (O) | Heat/Cool | Reversing valve control (for heat pumps) |
| Green (G) | Fan | Fan control for air circulation |
3 more rowsSep 6, 2023
Red wires are secondary live wires in 220-volt circuits and can also be utilized in various switch legs. Red wires are mostly used to connect the home's power system, and hardwired smoke detectors such that if one alarm goes off, all of them go off.
Which wire is positive red or green? ›
Red color indicates the positive wire with 5 volts of DC power. Black is always the ground wire in almost all electronic devices.
What happens if a zone valve is installed backwards? ›
If the valve is installed backwards, the flow of water catches the closure ball, overrides the spring, the valve snaps shut, and the water slams to a halt.
What is the A and B on a Motorised valve? ›
If you have a mid position valve - the one that makes a T junction, one pipe goes to the hot water cylinder (marked B on the zone valve), and the other to the central heating (A). The pipe marked AB comes from your boiler, so it should be hot.
What does the grey wire do on a 3-port valve? ›
If the system can easily meet your hot water demand (or no demand exists), 230 volts of electricity will travel along the grey wire, to turn off the hot water. Once this happens, the grey wire powers the motor (again with 230 volts) once switch one has moved position.
What is the white wire for on a Honeywell 2 port valve? ›
The extra white wire is another type of live: it acts as a signal or switch input for either the heating or hot water circuit, moves the motor round and turns the boiler or pump on. It's a little extra system safeguard so the boiler of pump don't run unnecessarily when there's nowhere for the water to flow to.
The National Electrical Code states that grey wire must be used for neutral conductors. These wires may still carry power that can give an electric shock and injure you. Neutral wires deliver power back to the service panel. The standard grey wire is known as the Line-phase 3 in its AC code.
Is grey wire negative or positive? ›
IEC DC power circuit wiring color codes
| Function | label | Color |
|---|
| 3-wire earthed DC Power System | | |
| Positive | L+ | brown |
| Mid-wire | M | blue |
| Negative | L- | grey |
9 more rowsWhite or gray wires indicate neutral charged wires. However, neutral wires may carry power and pose a danger of electrocution if not handled properly. White and gray wires carry power back to the service panel. Both hot and neutral wires have the potential to shock and injure you if not handled properly.
What are the wires on a 3 port valve? ›
3 Port Valve Operation
Electrically, the valve has 5 wires: Green/Yellow, Earth – connected to the metal body of the valve. Blue, Neutral – internally connected to the neutral side of the motor. White, Live in 1 – Activates the motor inside the valve to select either AB (both) or A (heating)
What are the Colours of zone valve wire? ›
Zone valves
The valves have 5 wires - blue neutral, green/yellow earth. Brown is connected to the motor inside, grey and orange are connected to an internal switch. When 230V is connected to the brown wire, the motor opens the valve and the switch inside connects grey and orange together.
Where does the white wire go on a Honeywell? ›
The white wire on your thermostat connects to your heating system. It connects your thermostat to your air handler or furnace. The white wire connects to terminal W in most industry-standard thermostats. If your HVAC system has multiple heating stages, then you may find more than one white wire.
