New & Boxed - ‘Rare & Discontinued’ - ESI 5 Series Programmable Room Thermostat ESRTP5. ESi 5 Series Wired Programmable Thermostat - ESRTP5 Overview. The ESi ESRTP5 programmable thermostat is great for tenants, as it automatically sends the landlord an alert if the boiler is due a service, and it'll even display an error code or diagnostics if there's a breakdown with the boiler.
