This has been going on for about 3 years, and incompetent Google will not address the problem. I asked the senior team 3 years ago to rectify the icon colour, as I feel the Orange proves the hot water is on and would then also match the heating colour.
Well after 3 years, nothing!!
You will also notice,if the thermostat is wired ONLY, and not linked wireless the hot water is indeed orange.
Another way is if a restart is done, again the hot water icon goes orange, but only for about 2-3 mins.
I would have thought Google and their big hot shots could have sorted such a simple issue out. Sadly not!
No, this is software problem and is known to Nest.
You can trick the thermostat to show orange icons on both, ONLY if you hard wire and NOT connect wireless. Pretty pointless as the idea is for a wireless thermostat.
There are some original 3rd gen thermostats out there that show BOTH icons in the orange state, and I do have one. I would think most users will have the grey hot water icon sadly.
Having said all that, Nest rectify the problem which has been going on for years, and you have never sorted.
OK - just to clarify - I have the UK edition which uses a heat link box and switches mains voltages. My thermostat is connected wirelessly to the heat link. Mine definitely shows an orange status for the hot water when it comes on, but it reverts to grey (still showing hot water as on during the programmed period) when the cylinder thermostat opens (tank reaches the temperature set on the tank). I do not know how it does this, but it must be able to sense the very small current to neutral through the completed circuit.
Yes UK with Heat Link
OK, so you have yet another configuration!
Mine is orange at all times when either heat or hot water is called for.
Mine is hard wired and wireless, and I an running a system oil boiler.
This is very interesting, as 99% of the stats fitted go grey with the words 'ON' for hot water, but the heating always is orange when called for.
The connections at the Heat Link relays are they 2&3 - 5&6