20 May 2021

Have I Got Questions For You…

When it comes to heating controls, the market for modern programmable thermostats has changed drastically in recent years. And as home technology advances, it is more important than ever for manufacturers to provide enhanced levels of technical support that helps to ensure products are installed in an optimal way.

Today, products such as the Honeywell Home T4 Series are packed full of smart, intelligent features. Terms such as TPI, OpenTherm and TRV now an important part of the lexicon.

Fortunately, Resideo’s dedicated support team is on hand to provide installers and contractors with advice on a wide range of technical issues for its domestic heating and water control products.

So, what are the most common enquiries we receive? Here’s a helpful round-up of our top tips. 

  • Where’s the best place to position a room thermostat?

The performance of all room thermostats is affected by the air flow measured around them. If it is poorly located, the air flow will not be representative of the rest of the room, and the temperature control will be adversely affected.

Avoid placing thermostats in a room with another major heat source such as an open fire, gas fire or cooker. Also make sure it isn’t fitted in an unheated room, in direct sunlight, or behind furniture or curtains. Don’t forget that electrical appliances can emit heat, so avoid fitting thermostats near TVs for example.

It is recommended that room thermostats are located in the heated area (zone) requiring control where it has a free flow of air around it on wall at a height of about 1.2m.

  • How does TPI (Time Proportional & Integral) work?

TPI enables the ‘smart’ firing of the boiler just long enough to achieve the set temperature and no longer, increasing energy efficiency in the process.

A TPI room thermostat works by continuously measuring the room temperature and calculating a difference between measured and target temperature. When the difference is greater than 1.5 degrees C (known as outside proportional band) it fires the boiler continuously.

When the room temperature gets within 1.5 degrees C of the set point you have chosen on the room thermostat, the TPI software in the thermostat comes into action. It performs a series of calculations where it calculates how long the boiler needs to be fired to reach and maintain the set temperature. The calculation is based on the previously learnt characteristics of the room in which the controller is placed and the current measured temperature.

  • What is Optimisation?

Most UK heating systems waste energy by firing unnecessarily early for most of the year. Homeowners set the times based on when they wake up, but then make a guess about when the boiler should fire. So, if you want to be warm at 7.30am, you may set your timer to come on 6am. Yet the time taken for your home to warm up varies considerably throughout the heating season.

Optimisation allows for energy savings, by varying the start-up time of the boiler, depending on the weather. It then learns how the house reacts, so that the calculation can be more accurate the next day. Optimum Start, Delayed Start and Optimum Stop are all methods of Optimisation.

  • Can a Programmable Thermostat be used as an on/off timer?

Some of the most frequently asked questions we receive are due to a misunderstanding as to how the thermostat operates – questions such as ‘my programmer is not turning my heating off.’

Remember that the thermostat is not designed to be an ON/OFF device. It will always be working, matching the time to a temperature requirement. Unlike a heating time control, the programmable thermostat is always working 24 hours a day.

If you’ve got a technical question, please contact our support team on 03457 678999, but please be patient at busy times. Alternatively, if the matter is not urgent then send an email and your query will be answered at the earliest opportunity.