A thermostat used to turn on a heating system automatically when the ambient temperature drops below a set threshold.
（环境温度低于设定限度时自动打开供暖系统的）霜式恒温器，霜式温度自动调节器
Example sentencesExamples
The control panels have adjustable temperature control, frost stats, economy and sleep modes plus other features.
You probably have a separate frost stat somewhere or there is one built into the boiler which is cutting in to protect the system because of the low night time temp lately.
It can completely replace all existing time clocks, optimisers, frost stats etc., with all the required control functionality housed in one low cost controller.
The pipe stat is connected in series to the frost stat so that when the return is at about 20 deg C the boiler turns off.
Typically on systems with external frost stats the norm would be to set these at between 1 and 4 degrees C.
On these frost stats you normally insert a small screwdriver under the round plastic cover to lever it off and underneath a similar dial to the room stat will be found but with lower temperatures on it.
Using a frost stat means that if you have a mild day, the tubes aren't running needlessly and this saves electricity.
Perhaps a pipe stat on the return would shut the frost stat down once the return water is warm.
They incorporate the frost stat, full thermostat control, complete with wall mounting bracket.
The programmer is off, the cylinder stat is satisfied and their is no frost stat and yet the boiler just keeps firing away at odd times.
Sounds to me like your frost stat may be kicking in as the weather has been cold and your garage probably un-heated.
I'll pull the frost stat apart and turn it down as much as possible.
On the frost stat setting it does keeps the damp out and cold out very effectively, enough so to keep the bike clothing out there too.