Ways to ask your ZEB for heat
We often get asked which thermostats or third party room controls the ZEB prefers, and how they should be configured; the truth is that the ZEB only needs a simple on/off call for heat - when heating is needed. You can simply retain your existing thermostat and timer. There’s no need to adjust any settings, just use the ZEB as if you were using your fossil fuel boiler.
In fact a ZEB works with any thermostat and heating type including radiators, underfloor heating, microbore systems, mixed circuits and combinations thereof. It can be set to supply 35-80degC flow temperature - as required by your system.
While not essential, what does help the ZEB is a predictable demand profile - this helps the ZEB ensure it has the optimal charging profile. It is therefore very helpful to set your heating and hot water timings in your timer or heating/hot water programmer.
This also means advanced thermostat features like optimum start and optimum stop aren’t as beneficial as you would expect. This can appear counterintuitive, but the reason is that the ZEB is clever - so the thermostat doesn’t have to be.
Likewise the control cycle rate and anti-cycling run time that can be set in some thermostats isn’t essential - as ZEB takes care of that too.
Your ZEB can work with OpenTherm thermostats and can adjust to a load compensated variable flow temperature between 35 and 80 degC (default is 70degC).
Programmable Thermostats - these are increasingly popular and enable a combined time and temperature profile, you will need to make sure that there is also timing for the hot water (2 channels) if you use one of these to control the ZEB.
Smart Thermostats - these thermostats typically include an app control or automation to pause heating while away. Research by google shows a 6% benefit from this functionality when installed with gas boilers. We would expect a similar saving when installed with a ZEB.
ZEB App - the ZEB has its own app where you can set holiday schedules! When you’re away it helps for the ZEB to know that it shouldn’t expect to be needed. It will also show you the state of charge and operational mode, and whether the third party room thermostat is calling for heat.
TRVs - these self acting controls are helpful to prevent overheating in different parts of the home. They are increasingly being listed as a minimum standard in building regulations and from our perspective are a great thing. Independent tests at Salford University link show an 18% energy consumption saving with TRVs (on a gas boiler system). We would expect a similar saving with a ZEB.
For more information on how to get the best from your heating controls check out the manufacturer user guide for your controls and the energy saving trust advice https://energysavingtrust.org.uk/advice/thermostats-and-heating-controls/
