WIFI Enabled HW Time switch - not thermostat

[epatrickt]

We've a range cooker controlled by a Honeywell 1-channel 7 day timer (the 1-channel version of ST9400C) and we'd like to add the ability to override the program remotely to turn it on early/late as it takes ages to heat up. I can see lots of questions/answers pointing to thermostatic controllers (like the Drayton miGenie) but not to a WIFI enabled switch to replace mine. Is there one? Maybe I am searching with the wrong terminology.

Thanks

 

[MeldrewsMate]

You can use a WiFi thermostat to do what you want if you choose one that has volt-free contacts, or use its output to energise an external relay. Simply ask it to supply a very high temperature (say 30C) when you want it ON, and a low temp when you want it OFF.

There are WiFi switches available, I have a SONOFF basic switche, which can be configured/wired to command your override. They also do a WiFi and RF version so that you have the choice of operation by Smarty-pants phone or a key-fob when at home. Typical cost between £5 and £10 each.

Another solution could be the GSM switches commonly used for remote gate opening/door unlocking. They allow simple switching of a volt-free contact via either a text message or a (n unanswered) telephone call. These are good where no t'interweb is available, or indeed for resetting the modem/router in areas where the router needs to be reset frequently! Search for GSM switch, or CL1 switch, or variations upon these. Typically £25 each, plus a quid for a Pay As You Go SIM card.

Hope this helps,
MM

 

[epatrickt]

Thanks MM, that is helpful. Some something like the Drayton MiGenie Single would do it I think, from what you say? We'd still have the separate thermostat which I guess we'd have to put somewhere that will never get hotter than the maximum set-point that may be programmed on the control panel? Given that it is wireless, I suppose there wouldn't be a way to link it out, which would then give us the controller that we'd want? I'm surprised that only thermostatic controllers are on the market and no direct replacement for the Honeywell programmer that we have. We've another similar controller turning on the hot water system, it too doesn't want a thermostat as part of the programmer.

The Sonoff is very attractively inexpensive. I guess I could find a home for it in the control panel of the cooker. You're suggesting that it controls the cooker in parallel with the existing panel? That is, so it could bring on the cooker even if the main controller is not involved? Standard programmers like the Honeywell don't have an external input to turn on the override, do they? Prob nonsense, sorry.

Thanks for your help

Patrick

 

[MeldrewsMate]

...Given that it is wireless, I suppose there wouldn't be a way to link it out, which would then give us the controller that we'd want?

There could be, if you have the necessary skills.
I suspect the measuring element in the thermostat is a thermistor. If you can locate this and measure its resistance at about room temperature then you can replace it with a fixed value resistor.

We've another similar controller turning on the hot water system, it too doesn't want a thermostat as part of the programmer.

There's a reason for that. The hot water cylinder has its own strap-on thermostat that will be wired into the system to give temperature control of the hot water.

The Sonoff is very attractively inexpensive. I guess I could find a home for it in the control panel of the cooker. You're suggesting that it controls the cooker in parallel with the existing panel? That is, so it could bring on the cooker even if the main controller is not involved? Standard programmers like the Honeywell don't have an external input to turn on the override, do they?

Yes
Yes
No, they don't.