ESI ESRTD3 User manual

ESRTD3
Digital Room
Thermostat
User Instructions

Thank you for choosing ESi Controls.
All our products are tested in the UK so we are
confident this product will reach you in perfect
condition and give you many years of service.
However, for additional peace of mind, we
recommend you register your product online at
www.esicontrols.co.uk/warranty for your
extended warranty.
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User Instructions
What is a Room Thermostat?
An explanation for householders 4
Thermostat Display 5
What is Chronoproportional Control (TPI)? 5
What is Delayed Start? 6
Setting the Temperature 6
Contents

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An explanation for householders
A room thermostat simply switches the heating system on
and off based on room temperature. It works by sensing
the air temperature, switching on the heating when the air
temperature falls below the thermostat setting and switching it
off once this set temperature has been reached.
Turning a room thermostat to a higher setting will not make
the room heat up any faster. How quickly the room heats up
depends on the design of the heating system, for example, the
size of the boiler and radiators. Neither does the setting affect
how quickly the room cools down. Turning a room thermostat
to a lower setting will result in the room being controlled at a
lower temperature, and saves energy. The heating system will
not work if a time switch or programmer has switched it off.
The house insulation quality is a key factor in heating control.
The way to set and use your room thermostat is to find the
lowest temperature setting that you are comfortable with, and
then leave it alone to do its job. The best way to do this is to
set the room thermostat to a low temperature – say 18°C and
then turn it up until you are comfortable with the temperature
(20°C is the usual preferred set point). You won’t have to adjust
the thermostat further. Any adjustment above this setting will
waste energy and cost you more money.
If your heating system is a boiler with radiators, there will
usually be only one room thermostat to control the whole
house (but building regulations Part L require houses above a
certain size to have more than 1 heating zone).
What is a Digital Room
Thermostat?

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Room thermostats need a free flow of air to sense the
temperature, so they must not be covered by curtains or
blocked by furniture. Nearby electric fires, televisions, wall or
table lamps may prevent the thermostat from working properly.
Also keep out of direct sunlight
N.B. This thermostat has the option of standard setting or TPI.
Thermostat Display
This product has an internal non-replaceable rechargeable
battery to power the display when the system is between
heating cycles. To conserve power this will run for up to eight
hours and if the heating intervals are more than eight hours
apart, the display will “go to sleep” – although the thermostat
is still active. When mains power is restored, the battery
automatically recharges. This is a design feature to ensure
the delayed start thermostat clears its memory at the end of
every heating cycle.
What is Chronoproportional Control (TPI)?
A chronoproportional (or TPI) room thermostat makes boilers
operate more efficiently and provide close accurate control.
Chronoproportional control is a load compensator as it
ensures that the boiler ‘ON’ time is reduced to a minimum
and matches the boiler heat output with the heat loss. This
reduces the net temperature of the return water to the
boiler. This is due to the TPI (Time Proportional and Integral)
advanced energy saving feature.
Rather than just a simple ON/OFF control, like other domestic
room thermostats, room thermostats with TPI increases
boiler efficiency by firing the boiler at regular intervals,
adjusting firing duration with demand, to maintain set
room temperatures, giving them a great advantage over
other domestic room thermostats and achieving a constant

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ambient environment for the user e.g. if a property only has
a simple mechanical thermostat installed, then the energy
saving benefits of a replacement high efficiency condensing
boiler will not be realised as the boiler will rarely be running in
condensing mode.
Heating and hot water can account for over 80% of
total household energy usage. Chronoproportional (TPI)
thermostats can provide great cost savings. It can be used
on any boiler, with underfloor and radiator systems, zoned
heating and electric heating systems. The use of an electronic
thermostat with chronoproportional capability provides closer
temperature control plus possible reductions of 10% in both
fuel cost and carbon emissions. This thermostat has the
option of standard setting or TPI.
What is Delayed Start?
The ESi Delayed Start function offers real energy savings. Save
as much as 10% on your heating costs. This feature delays
the start-up of the heating, depending on how warm the
room temperature is at the time when the central heating is
due to come on.
The heating start can be delayed for up to an hour if the room
is already relatively warm, when the weather is milder for
example. This often reduces how long the heating is on per
day, with no comfort loss, saving you energy and money! The
delayed start feature can be fully automated and needs no
extra programming.
Setting the Temperature
To set the temperature, turn the dial until the desired
temperature is shown in the LCD display. The LCD display will
flash the desired temperature for (approximately) 5 seconds
before returning to display the current room temperature.

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We are continuously developing our products to
bring you the very latest in energy saving technology
and simplicity. However, should you have any
questions setting up your controls please email us at
[email protected].
WARNING: Interference with sealed parts renders the
guarantee void.
In the interests of continuous product improvement we reserve
the right to alter designs, specifications and materials without
prior notice and cannot accept liability for errors.

Version 6.10.2
© ESi Controls Limited 2017