Reverse Thermostat

[Halo]

I have thermostats on the tube heaters in my boat. The heaters come on at 5 degrees so I dont waste a much electricity when there is no frost risk.
I also have compressor type de humidifier which has a humidistat. I think this runs very inefficiently when it is cold and would like a thermostat to switch on at temperatures above 9 degrees and off below it. My conventional thermostats switch off when it gets warm. Can anyone suggest a cheap and simple way of reversing this so it switches off below 9 degrees and on above it?

 

[rogerthebodger]

I have thermostats on the tube heaters in my boat. The heaters come on at 5 degrees so I dont waste a much electricity when there is no frost risk.
I also have compressor type de humidifier which has a humidistat. I think this runs very inefficiently when it is cold and would like a thermostat to switch on at temperatures above 9 degrees and off below it. My conventional thermostats switch off when it gets warm. Can anyone suggest a cheap and simple way of reversing this so it switches off below 9 degrees and on above it?

A normal fridge thermostat would do that

 

[VicS]

I have thermostats on the tube heaters in my boat. The heaters come on at 5 degrees so I dont waste a much electricity when there is no frost risk.
I also have compressor type de humidifier which has a humidistat. I think this runs very inefficiently when it is cold and would like a thermostat to switch on at temperatures above 9 degrees and off below it. My conventional thermostats switch off when it gets warm. Can anyone suggest a cheap and simple way of reversing this so it switches off below 9 degrees and on above it?

Here is a plug in one that will do what you want

https://www.amazon.co.uk/PLUG-COOLING-ONLY-THERMOSTAT-13AMP/dp/B00BWS5POA

 

[Halo]

Nice one Vic

 

[ghostlymoron]

Unfortunately, unavailable but no doubt you can get them elsewhere.

 

[pvb]

This one does it, about a tenner. http://www.directtradesupplies.co.uk/product.php/9338/robus-230-240v-thermostat--white-?

 

[davidpbo]

As probably with the above, some standard thermostats have 3 poles, a common, normally open and normally closed so they can be used to switch either way. If you have one in a bits box it would be worth having a look.

 

[Spirit of Glenans]

Here is a plug in one that will do what you want

https://www.amazon.co.uk/PLUG-COOLING-ONLY-THERMOSTAT-13AMP/dp/B00BWS5POA

The thermostat linked is "for cooling only" and will come on when temp rises above a selected setting. That is, unless I need a visit to Specsavers

 

[pvb]

The thermostat linked is "for cooling only" and will come on when temp rises above a selected setting. That is, unless I need a visit to Specsavers

Think the Specsavers trip is a good idea! Did you read the OP?

 

[VicS]

The thermostat linked is "for cooling only" and will come on when temp rises above a selected setting. That is, unless I need a visit to Specsavers

Thats right. The OP wanted one to switch ON only when the temperature is above 9C.

However the last one has now gone .... maybe the OP bought it.

I have ordered one of those in PVB 's link for switching on a ventilation fan above a set temperature. ( It has both NO and NC contacts)

 

[Spirit of Glenans]

Think the Specsavers trip is a good idea! Did you read the OP?

No, in this case I think I need to drink a cup of coffee and turn down the central heating thermostat

 

[thalassa]

Well, I use http://www.banggood.com/STC-1000-220V-All-Purpose-Digital-Temperature-Controller-Sensor-p-91676.html?rmmds=search for exactly that since two years.