The ESI ESRTERFW mixes older and newer technology together quite seamlessly. The simplicity of a mechanical dial with the digital temperature accuracy of a mini LCD screen. Not only that, but it’s also kitted out with wireless [RF technology]. This model is extremely easy to use and fit / wire up.
This model also benefits from chronoproportional (TPI), a feature that can help with overall efficiency. One area where It helps is cutting the time a boiler is on for by working in unison with the boiler heat output Vs heat loss, and activating the boiler more often for short periods to keep an even overall temperature.
The high level temperature accuracy of TPI tailors boiler activitation more efficiently to meet the users needs. So rather than it being constantly “On” or “Off”, the ESRTERFW’s TPI cleverly manages the system and adjusts as necessary. This can potentially lead to a saving on energy bills / usage.
ESI’s ESRTERFW works with many types of systems, and being easy to use, very resourceful, and compatible with the industry standard backplate, it is a favourite budget RF thermostat for Eco and oil fired combi boilers. A very cheap but capable RF thermostat that does the job. A few things to note: There are some reports of the temperature accuracy being slightly off on the display.
This is not widely regarded as a huge problem that affects all users, but a few customers have experienced this issue. Also worth mentioning: There is no light on the digital display. It does not illuminate at all. Needless to say, using this model in a dark environment will require an external light source in order to see the screen. Certainly not a deal breaking issue, but it would have made it much more convenient for users if ESI would have fitted a small light in the ESRTERFW.