Just thought I’d share this as I couldn’t find a solution to this particular conundrum: we recently finished building a weekend home with hydronic floor heating, split into four zones, with a Honeywell Aquatrol boiler control. All I really want is to be able to remotely turn the heat off if I forgot to do it in person before I left, and turn the heat on when I know I’ll go there so the house isn’t freezing when I arrive. The contractor was saying that yes this could be controlled via internet through Honeywell’s RedLink and that’s what I use at home, so I trusted that. However, come time to actually get serious about this, since all the smarts are in the boiler control and the four thermostats (one per zone) are dumb, RedLink doesn’t really help unless I switch out all of them and then have to remotely fiddle with all four. I contacted Honeywell support for that, and they told me to
- program the Aquatrol to interpret the auxiliary input as the “vacation mode” input and
- use any RedLink thermostat’s fan control output as a means to tickle that input.
That struck me as quite a hack, but thinking about it I realized that given the first part, that there was an input that could be used to toggle vacation mode, all I really needed was a relay that I could reach via internet. After a little bit of research I went with a SmartThings hub and the Evolve LFM-20 relay, wired that onto the controller and tada - the vacation home furnace has a remote control. The boiler control is smart enough to keep an eye on temps and not let it drop into the freezing range.
Now I am looking for a way to remotely control the hot tub - The Wife requires the hot tub to be hot within a couple of hours of arrival, and I require it to not waste insane amounts of power. I am thinking I’ll have to go with just a monster 50 Amp relay to flip the power on/off, but then the freezing protection in the hot tub is off too, so this will need some more smarts about checking for temp and turning the power back on when things are getting icy in there. I don’t see a solid solution for that but I may be just not looking into the right places ? This seems like a relatively common scenario to me. Any pointers appreciated on the hot tub topic, hope the boiler control vacation mode hack helps somebody,