Answer
This article refers to Hive Receivers, which are part of the Hive Heating controls. The Hive Receiver is the component that is wired to your boiler and will look similar to the below image.
TIP: The left image is our single channel receiver, which only controls heating and is installed on combi boilers. The right image is our dual channel receiver, which controls heating and hot water and is installed on conventional boilers.
NOTE: OpenTherm is only compatible with combi boilers; therefore, will only work with a single channel receiver.
Standard (Relay) Mode
- How does Standard (Relay) Mode work?
- In Standard (Relay) Mode, Hive acts as an electronic switch, turning the boiler on when the thermostat’s target temperature is above the actual temperature. The boiler heats water, which is sent to radiators via the central heating system’s ‘flow’ pipes. This water is heated to the boiler’s set ‘flow’ temperature, which can be inefficient – more on that below.
- What happens if the flow is too low?
- If the flow temperature is set too low and the heating has been off for a while, it takes longer to heat up the home, using more energy and costing more. On a cool day, the home will take a long time to warm up, which is inefficient.
- What happens if the flow is too high?
- If the flow temperature is set too high, the home heats up quickly, but the boiler runs at maximum power, using more energy. When the thermostat balances room temperature, the boiler sends out warm water, causing ‘temperature overshoot.’ This cycle of reaching, overshooting, and dropping below the target temperature is inefficient and can wear out the boiler, requiring more frequent servicing. Additionally, higher water temperatures increase radiator corrosion, leading to sludge buildup that needs flushing out.
OpenTherm
- How is OpenTherm more efficient?
- OpenTherm is a communication protocol used by modern condensing boilers and OpenTherm-enabled controls. It allows boilers and controls to share more information via load compensation (or modulation), which helps improve efficiency.
- Modulation through OpenTherm allows the boiler to reduce power when only a little heat is needed. This ensures the Hive thermostat heats the radiators to the desired temperature and then lowers the boiler’s power output. This stops the temperature from going too high and keeps the heat balanced in the home.
- This intelligent power switching based on the home’s heat demand allows you to set and forget the system. You won’t need to manually adjust the boiler’s flow temperature for different seasons. As the boiler changes its power output to match demand, you’ll use less energy and save more.
- Benefits of OpenTherm
- Extended boiler lifespan: Reduces corrosion and dirt buildup through less thermal shock and lower cycling.
- Increased comfort: Lower temperatures, efficient heat transfer, less cycling, and added condensing at the boiler.
- Improved efficiency with boiler condensing: Ensures the returning water isn’t too warm, maintaining low temperatures during periods of reduced demand.
How does boiler condensing work?
- Heat extraction: When the boiler burns fuel, it produces hot gases. In a condensing boiler, these gases are cooled down to extract additional heat.
- Condensation: As the gases cool, they condense into liquid water. This process releases latent heat, which is then used to heat the water in the boiler.
- Efficiency: By capturing this extra heat, condensing boilers can achieve higher efficiency levels compared to traditional boilers, which simply expel these hot gases through the flue.
This process not only makes the boiler more efficient, but also reduces energy consumption and emissions.