Drayton LP711 Thermostat Wiring Diagram
Drayton LP711 7-day timeswitch wiring
Wall plate with the 230 V mains and the changeover contact; choose how terminal 1 is fed.
Terminals and components · 6
- Live
- Neutral
- Common (COM)
- L–1 link
- OFF output
- ON output
Connection
Run the neutral from the same 230 V AC, 50 Hz circuit that feeds terminal L.
Function
Powers the internal clock. The output contact is volt-free: it only delivers 230 V if you fit the link between L and terminal 1.
Caution
- Installation must only be carried out by a qualified electrician or heating engineer.
- Switch off the mains before starting and before removing the unit; never fit it to a live wall plate.
- The mains input must have a 3 A fuse.
Earth
The unit is double insulated and needs no earth; the wall plate has an earth loop terminal to keep the cable's earth continuous.
L–1 link
With the link between L and terminal 1 (dashed line), outputs 2 and 3 deliver the 230 V mains live.
Caution
- Contact rating: 2(1) A at 230 V AC.
Separate supply
Without the link, the contact is volt-free: feed terminal 1 with the voltage it must switch, from a separate supply protected by a 3 A fuse.
Caution
- The 3 A fuse on the separate supply is required.
- Contact rating: 2(1) A at 230 V AC.
Use
Usually left free. Use it only if some equipment must be powered while the program is off.
Caution
- Contact rating: 2(1) A at 230 V AC.
Connection
Run this terminal to the control input of the equipment the timeswitch controls: the boiler, zone valve or hot water circuit (the LP711 controls heating or hot water, not both).
Caution
- Contact rating: 2(1) A at 230 V AC.
Use
The timeswitch doesn't use this terminal. When replacing another unit, you can use it to join a wire that must not connect to the timeswitch.
About This Diagram
This diagram is redrawn from pages 2–3 of the Drayton LP711 Thermostat Installation Instructions, and we offer it completely free and in English. We have also categorized it in the Thermostats (HVAC & Water Heating) section on Diagramverse, and it has been rated by 1 user with an average rating of 5.0. If you have any specific questions about the Drayton LP711 Thermostat Wiring Diagram, we suggest checking the Frequently Asked Questions (FAQs) section.
Printable Drayton LP711 Wiring Diagrams
Wiring Instructions
Before you start
The Drayton LP711 is a single-channel 7-day timeswitch powered by 230 V AC mains. It switches one circuit, either heating or hot water, and is often used with combination boilers or to add a zone. Fit it only if you are a qualified electrician or heating engineer. The wiring is fixed wiring and must comply with current wiring regulations, BS7671 in the UK. If you are not competent with mains work, or your local rules require notification or a permit, hire a professional.
- Tools: insulated terminal screwdrivers, a voltage tester or proving unit, a multimeter, a drill and wall plugs.
- Fixings: for a new wall-plate, use No. 6 x 1" (25mm) woodscrews to fix it to a flat wall, or M3.5 x 14 bolts to fix it to a UA1 flush single conduit box. Do not use a surface mounting box.
- Supply: the mains input must have a 3 A fuse, usually a fused spur with a mains isolator.
- Cable: the documentation does not give a conductor size. In UK practice, 1.0 mm² or 1.5 mm² cable on a 3 A fused circuit is common. Size the cable for your circuit and local regulations.
Choose your variant. The output contacts are volt-free, so the selector offers two arrangements:
- L–1 link (230 V output): use this when the boiler or valve needs a 230 V switched live. This is the usual setup.
- Separate supply: use this when terminal 1 COM has to be fed from another circuit, which must have its own 3 A fuse.
Plan the location. Mount the unit about 1.4 m above the floor. Pick a spot with reasonable light and good access, away from condensation and temperature extremes, on a surface that covers the whole back of the unit. Leave 70mm clear to the right and 25mm above, and enough room below to reach the securing screws.
Step-by-step wiring
- Switch off the mains at the isolator and remove the 3 A fuse. Prove the circuit dead with a tester that you have checked on a known live source. If you use the separate supply variant, isolate that circuit as well.
- If you are replacing an old timeswitch, loosen its securing screws and unplug it from the wall-plate. Older Drayton Lifestyle and Tempus timeswitches use the same N, L, 1, 2, 3, 4 layout. Other makes often number their terminals differently, so identify every existing wire by its function (neutral, live, common, on, off) before you move anything.
- For a new wall-plate, fix it with the terminals at the top. If the cables run on the surface, snap out the cable entry strip on the bottom edge of the wall-plate.
- Connect the mains neutral to Neutral (N) and the fused live to Live (L). These two terminals power only the clock.
- Feed terminal 1 COM. For the L–1 link variant, fit a short link from Live (L) to terminal 1. For the separate supply variant, connect the live of the other 3 A fused supply to terminal 1.
- Connect the circuit that must run during programmed on periods, such as a boiler switched live or the feed to a room thermostat, to terminal 3 ON.
- Connect terminal 2 OFF only if a device needs a supply while the program is off. Otherwise leave it empty.
- Use Spare terminal 4 only to join conductors that must not connect to the timeswitch. It has no internal connection, so never land a load wire there and expect it to switch.
- The unit is double-insulated and needs no earth. Join any earth conductors at the wall-plate's earth continuity terminal so the protective earth stays continuous to the rest of the circuit.
- Check that every screw is tight and no bare copper shows outside the terminals. Gently pull each wire to confirm it is clamped.
- With the mains still off, plug the timeswitch onto the wall-plate and tighten the securing screws. Never fit it to a live wall-plate.
Testing and start-up
- Before you restore power, check with a multimeter on continuity. Terminal 1 to terminal 2 should read closed while the unit is unpowered or off, and terminal 1 to terminal 3 should read open. If you use the L–1 link, there should be continuity between L and 1.
- Refit the 3 A fuse and switch on the mains. The display should light. The clock is set at the factory and changes for summer time automatically, so check that the time and day are correct.
- Use the SELECT button under the flap to choose ON, or press Boost. The red light should come on. With the L–1 link, you should measure about 230 V between terminal 3 and Neutral (N), and the boiler or valve should respond. With a separate supply, terminal 3 should carry whatever voltage you fed to terminal 1.
- Choose OFF. Terminal 3 should drop to 0 V and terminal 2 should become live.
- Return to TIMED and program the timings, or leave the factory program running. In the factory program, ON2 and OFF2 are set to the same time, so the middle period does nothing until you change it.
Safety notes
- All terminals carry 230 V AC, including terminals 1, 2 and 3 when the link is fitted. Treat the whole wall-plate as live whenever the supply is on.
- Each contact is rated 2(1) A at 230 V AC. Do not switch heavy loads such as pumps or immersion heaters directly. Switch them through a relay or wiring centre instead.
- With a separate supply, the wall-plate is fed from two circuits. Label both circuits and isolate both before any work.
- Always switch off the mains before you remove the timeswitch from its wall-plate.
Troubleshooting
| Symptom | Probable Cause | What to Check |
|---|---|---|
| The display is completely blank. | No mains reaching Live (L) and Neutral (N): the 3 A fuse has blown, the isolator is off, or a supply wire is loose. | Measure between L and N on the wall-plate. You should see about 230 V AC. If there is none, check the 3 A fuse, the isolator and the terminal screws. |
| The red light comes on but the boiler never fires. | Terminal 1 COM has no supply: the L–1 link is missing, or the separate supply is off. The output contacts are volt-free and cannot produce voltage on their own. | With the unit in ON, measure terminal 1 to N and terminal 3 to N. Both should read about 230 V with the link variant. Fit the L–1 link or restore the separate supply. |
| The heating runs when it should be off and stops during programmed on times. | The load is wired to terminal 2 OFF instead of terminal 3 ON. | Isolate the supply and move the switched-live wire from terminal 2 to terminal 3. Then confirm that terminal 3 is live only in ON or during timed periods. |
| Nothing happens at all, even though the clock and red light work. | The load wire is landed on Spare terminal 4, which has no internal connection. | Check which terminal the boiler or valve wire is in. Move it to terminal 3 ON. Terminal 4 is only for joining wires. |
| The fuse blows or the breaker trips when the program switches on. | The load exceeds the 2(1) A contact rating, or there is a short circuit on the output wiring. | Disconnect the load from terminal 3 and test its insulation and current draw. Drive a heavy load through a relay or wiring centre instead of directly. |
| The boiler stays live after I switched off the timeswitch fuse. | You are using the separate supply variant, and terminal 1 COM is fed from a second circuit. | Prove dead at terminals 1, 2 and 3 as well as at L and N. Isolate and label both circuits before working. |
| The heating cuts in and out, or the unit restarts when touched. | A wire is loose in its terminal, or the timeswitch is not fully seated on the wall-plate. | Isolate, then retighten every terminal and gently pull each conductor. Re-seat the unit and tighten the securing screws underneath. |
| The timeswitch light is on and terminal 3 is live, but the radiators stay cold. | The room thermostat wired after terminal 3 is satisfied, or it is wired to the wrong terminals. | Turn the room thermostat up. Then measure its output terminal to N. It should pass the 230 V from terminal 3 to the boiler while calling for heat. |
| The timeswitch switches on the wrong day or at the wrong time. | The date is wrong (the weekday is worked out from the date), or summer time is set incorrectly. | Use SET? to open SET CLOCK and SET DATE. Correct the year, month and day, and check the summer time setting. |
| The midday heating period never runs. | In the factory program, ON2 and OFF2 are set to the same time, so the second period is inactive. | Reprogram ON2 and OFF2 to different times, in sequence, for the days you need. |
Frequently Asked Questions (FAQs)
Is the Drayton LP711 a thermostat?
No, the LP711 is a 7-day electronic timeswitch, not a thermostat. It switches a circuit on and off at the times you set, with up to three periods per day and different timings for each day of the week. It does not measure temperature. For temperature control, wire a room thermostat or cylinder thermostat after terminal 3 ON so that the boiler runs only when the timeswitch is on and the thermostat is calling for heat.
Should I use the L–1 link or a separate supply?
Use the L–1 link when the controlled device needs a 230 V switched live from the timeswitch, which is the usual setup with combination boilers and valves. The link powers terminal 1 COM from the same 3 A fused live as the clock. Choose a separate supply only when terminal 1 must be fed from a different circuit. That circuit needs its own 3 A fuse, and both circuits must be isolated before any work.
Does the LP711 need an earth connection?
No, the LP711 is double-insulated and needs no earth connection. However, the wall-plate has an earthing continuity terminal. Use it to join incoming and outgoing earth conductors, so the protective earth continues to the boiler, valves or other equipment on the circuit. Never cut back or leave loose an earth conductor just because the timeswitch does not need it.
What does the 2(1) A rating mean?
The output contact can switch up to 2 A at 230 V AC for resistive loads and 1 A for inductive loads, such as motors, pumps and valve actuators. The same rating applies to terminal 2 OFF and terminal 3 ON. If your load draws more than this, switch it through a relay or wiring centre instead of directly through the timeswitch.
Can I swap an old timeswitch for an LP711 without rewiring?
Often yes, because the LP711 uses an industry-standard wall-plate with N, L, 1, 2, 3 and 4 terminals. Other Drayton Lifestyle timeswitches and many Drayton Tempus models use the same layout, so in most cases you can unplug the old unit and plug in the new one. Many other brands number their terminals differently, though. Identify each wire as live, neutral, common, on or off, and rewire the wall-plate to match before fitting.
Is the LP711 suitable for a combination boiler?
Yes, the LP711 suits combination boilers. It is also used to control an additional heating zone. Its volt-free contact lets it provide a 230 V switched live through the L–1 link, or switch whatever supply you connect to terminal 1 COM. Before wiring, check the boiler handbook for its external control terminals, because some boilers expect a switched live and others need a volt-free contact.
Can the LP711 control heating and hot water separately?
No, the LP711 is single-channel, so it controls either heating or hot water, not both independently. If you need separate timings for central heating and hot water, use a dual-channel Lifestyle programmer such as the LP241, LP522 or LP722. Those use a different wall-plate terminal layout, so check their wiring before you change units.
What is the difference between the LP711, LP111 and LP711Si?
The LP711 offers different timings for each day of the week, while the LP111 repeats the same 24-hour program every day. The LP711Si adds a service interrupter: it warns the household when the boiler service is due and can reduce comfort levels if the service is ignored. The LP811 lets you choose LP111 or LP711 functionality at installation. All of them have up to three periods per day.
What happens to the LP711 during a power cut?
The display goes blank and the output stops switching, but the clock time and your program are kept. When power returns, the timeswitch resumes the stored program at the correct time without being reprogrammed. The clock is preset at the factory and adjusts automatically for summer and winter time.
What is terminal 2 OFF used for?
Terminal 2 OFF connects to terminal 1 COM whenever the program is off, so it is live with the L–1 link outside the on periods. Most heating installations leave it unused. It is for equipment that needs a signal or supply while the timer is off, such as a device that must be powered to close. Its contact rating is the same 2(1) A as terminal 3.
Where is the best place to mount the LP711?
Mount the LP711 about 1.4 m above the floor, with good lighting and access, away from condensation and extreme temperatures. Fix it on a surface that covers the whole back of the unit. Leave 70mm clear to the right and 25mm above, and room underneath to reach the securing screws. Fix it directly to a flat wall or to a UA1 flush conduit box, never to a surface mounting box.
What size cable should I use for the LP711?
Drayton does not specify a conductor size for the LP711, so follow your local wiring regulations, BS7671 in the UK. The circuit is protected by a 3 A fuse and each contact carries no more than 2 A, so standard fixed-wiring cable is usually enough. In UK practice, 1.0 mm² or 1.5 mm² is common. Make sure the cable size matches the protective device and the terminals clamp it securely.
