Honeywell L7248L aquastat features / settings

[FredBoston]

I hope the Pros monitoring this forum can help me, where Honeywell unfortunately has declined to provide information. Our oil company installed the aquastat along with a Solaia boiler & Riello burner, but they don't seem up-to-date on the L7248L features.

The aquastat's full model number is "L7248L 1070 1." The L7248L is connected to a Taco SR506, one of whose zones is indirect DHW. The SR506 connects only to the TT terminals on the 7248; right now the aquastat's ZR is not used. In the interest of saving energy and money I am investigating Honeywell Outdoor Reset modules.

- When I step thru the aquastat settings the only ones listed are HL_, F-C, and ELL. Could you please explain why duu, tPL, and tPt are * I do understand that the Reset settings (such as OtL, BtL) should be shown only when an approved reset module is detected on the Enviracom bus

Thank you very much for your help!

[FredBoston]

Well, now I can answer my own question. Sometimes a letter to the CEO gets you the cooperation you need - I spoke to a Honeywell product manager in their Environmental & Combustion Controls division.

The reason I don't see the settings I expected, is that my aquastat (date code 0829), while only 4 years old, has neither of the features that interest me. Although this basic (electronic) design was introduced in 2004, it was not until 2010 that Honeywell added Outdoor Reset capability, in spite of the fact that residential O.R. has been available for over half a century. Go figure.

As for Thermal Purge, it made its appearance only this year (2012) and not voluntarily. Federal energy efficiency regulations mandated this feature.

So, for my purposes, unfortunately my aquastat has all the features of Honeywell's analog design from 25 years ago, and if I want Reset I will have to buy a current-production L7248L.