While not “Smart” in the sense of what that word means in the new world of super advanced heating controls, ESI’s ESRTP4+ (Wired model + requires battery’s) still packs a fairly impressive ranges of features. It’s well rated for its precision [although some would disagree], ease of installation and setting adjustments. Making it a decent choice for those who want a large screen digital thermostat with the versatility of 7 day, 5/2 or 24 hour programming capabilities at a low price.
Frost mode, holiday mode, TPI [helps boilers manage enery usage better], automatic, manual, override, optimum and delayed start are some of the standout features.
There’s also a landlord service indicator, which can potentially limit the usage of the system if a service isn’t carried out within a certain timeframe. With this model that timeframe is thirty days before the service date. If the service isn’t performed the system will be limited. This can be useful for people who rent etc, and not really needed as much for those who have their own residence. Not to worry, It’s an optional feature that can be turned on or off when required.
Like most thermostats, this model can be found for sale used. But with how cheap it is to buy new, it doesn’t really make buying used a good option. By new and get the full 3 year warranty offered with the ESRTP4+ . Batteries were not included with early purchases [two AA]. But that does seem to have changed. Batteries are now included with the purchase.
Installation and userguide / PDF manual are all available for direct download on the Amazon product page, which can be found at the link above.
As well as the hard wired model, there’s also a wireless version of ESRTP4+. That’s conveniently called the ESRTP4RF+. This has practically the same features as the wired version but with the added wireless RF technology. That model can be found for sale here. Or see an alternative RF small screen version here.
Another wired model worth considering if this one happens to be sold out is the Danfoss TP5000Si. Very reliable, and most the time can be found for sale just as cheap as the ESI ESRTP4+.