Thermostatic Switches

Thermostats are used in temperature control systems regulating air or liquids and can be used in both commercial and domestic applications. The two main types are capillary and bimetallic thermostats.
RS Components offer a range of thermostats such as enclosure thermostats, mechanical HVAC thermostats, digital and programmable HVAC thermostats, digital and smart thermostats with Wi-Fi.

What Does a Thermostat Do?
It regulates the temperature of a liquid in a tank, or in conjuction with air conditioning units to monitor the air in a room/system. The thermostat simply switches the system off or on whenever necessary so that a constant temperature can be maintained. At home room thermostats switches on the heating when the room is cold and once the temperature has reached the level set, the programmable thermostat switches the heating off.

Capillary Thermostats
These consist of a sensor, capillary tube, diaphragms, a probe and an expansion medium. When the liquid heats up and expands, the temperature sensor is heated allowing for it to be converted into displacement in the diaphragm. The contacts within the closed circuit system can be opened or closed by this displacement due to pressure.
Due to their accuracy and easy installation, they are widely used to control air and water temperatures and are suitable for use in storage heaters, hot tanks and boilers to control hot water.

Bimetallic Thermostats
These consist of a strip of two different metals with different coefficients of linear expansion. The bimetallic strip acts as an electric contact breaker in an electric heating circuit. When the desired temperature is reached, the circuit is broken.
The strips of metal are bolted together. A bridge is then created in the electrical circuit and is connected to your heating system. The strip carries electricity through the circuit when the heating is on. When the strips get hot, both of the metals expand but one more so than the other. The hottest metal bends and opens the circuit. Once the circuit is open the electricity switches off and the heating cuts out.
Once the heating is off, the room cools down which in turn cools down the strip of metal and allows it to go back to its original shape. When it cools, the metal goes back into the circuit and switches the heating back on as the electricity flow has been re-established. The metal strip takes a while to expand and contract so the heating is not constantly switching on and off every few seconds.

...
Read more Read less

Filters

Viewing 161 - 175 of 175 products
Results per page
Description Price Minimum Temperature Maximum Temperature Opening Temperature Closing Temperature Thermostat Type Switch Configuration Contact Rating Contact Voltage Rating Terminal Type Mounting Type Reset Type Switch Function
RS Stock No. 764-5231
Mfr. Part No.604100/20-5-140-6000-0-40/404,
BrandJumo
£99.23
Each
Units
-10°C +15°C - - Capillary SP 16 A - Push In Wall Mount - -
RS Stock No. 764-5237
Mfr. Part No.604100/20-5-140-3000-0-40/404,
BrandJumo
£90.96
Each
Units
-10°C +15°C - - Capillary SP 16 A - Push In Wall Mount - -
RS Stock No. 357-7935
Mfr. Part No.603021/70-2-043-00-1000-40-10-00-00-000-00-6/000
BrandJumo
£190.20
Each
Units
+20°C +150°C - - Capillary - 10 A 230 V ac/dc Solder Tab - - -
RS Stock No. 357-9953
Mfr. Part No.603021/70-2-043-00-2000-40-10-00-00-000-00-6/000
BrandJumo
£196.02
Each
Units
+20°C +150°C - - Capillary NC 10 A 230 V ac/dc - - - -
RS Stock No. 111-7182
Mfr. Part No.ORA-425-QC
BrandSelco
£7.04
Each
Units
+10°C +260°C +425°F +375°F Bi-Metallic NC 10 A @ 250 V ac, 15 A @ 125 V ac 125 V ac @ 15 A, 250 V ac @ 10 A Quick Connect Rotating Bracket Automatic Open On Rise
RS Stock No. 111-7798
Mfr. Part No.OA-220-QC
BrandSelco
£5.39
Each
Units
+10°C +150°C +220°F +190°F Bi-Metallic NC 10 A @ 250 V ac, 15 A @ 125 V ac 125 V ac @ 15 A, 250 V ac @ 10 A Quick Connect Surface Mount Automatic Open On Rise
RS Stock No. 467-175
Mfr. Part No.603026/0102-1-042-30-0-00-20-13-46-150-15-6/000
BrandJumo
£238.36
Each
Units
+20°C +120°C - - Capillary NO/NC 0.25 (dc) A, 10 (ac) A 230 V ac/dc Screw - - -
RS Stock No. 821-3490
Mfr. Part No.3455RC 01000237
BrandHoneywell
£14.25
Each
Units
+52°C +260°C +113°C +96°C Bi-Metallic SPST 15 A 120 → 250 V ac Screw - - -
RS Stock No. 111-7149
Mfr. Part No.OA-120
BrandSelco
£5.39
Each
Units
+10°C +150°C +120°F +90°F Bi-Metallic NC 10 A @ 250 V ac, 15 A @ 125 V ac 125 V ac @ 15 A, 250 V ac @ 10 A Solder Tab Surface Mount Automatic Open On Rise
RS Stock No. 357-9947
Mfr. Part No.603021/02-2-064-30-2000-40-10-00-00-000-00-6/000
BrandJumo
£169.21
Each
Units
+50°C +300°C - - Capillary NO/NC 10 A 230 V ac/dc Solder Tab - - -
RS Stock No. 853-6633
Mfr. Part No.3100U 00031438
BrandHoneywell
£52.12
Each
Units
-29°C +260°C +43°C +32.2°C Bi-Metallic SPST 3 A 120 V ac PCB Pin PCB Mount - -
RS Stock No. 821-3459
Mfr. Part No.3100U 00031456
BrandHoneywell
£61.24
Each
Units
-29°C +260°C +15.6°C +26.7°C Bi-Metallic SPST 3 A 120 V ac Screw - - -
RS Stock No. 821-3421
Mfr. Part No.3100U 00031434
BrandHoneywell
£43.99
Each
Units
-29°C +260°C +21.1°C +10°C Bi-Metallic SPST 3 A 120 V ac Screw - - -
RS Stock No. 467-153
Mfr. Part No.603070/0020-5-671-000-70-2000-40-28-13-46-100-8-6
BrandJumo
£82.04
Each
Units
+70°C +130°C - - Capillary - - - - - - -
RS Stock No. 2508478142
Mfr. Part No.CAP-140-752
BrandSelco
£36.97
Each
Units
- - - - - - - - - - - -
Related Products
The surface-mounting thermostat works on the principle of ...
Description:
The surface-mounting thermostat works on the principle of volume expansion If the temperature of the filling medium in the probe system – which consists of probe, capillary conduit and diaphragm – changes, then the volume also changes. The resulting elevation of the diaphragm presses the snap-action switch via a lever. ...
The CAP series from Selco is a dynamic ...
Description:
The CAP series from Selco is a dynamic range of bulb and capillary thermostats which feature a fluid filled bulb. The ceramic thermostats have a compact design and have been created to work in a variety of different applications including food service equipment, test systems and heaters to name just ...
This range of capillary and rigid stem surface ...
Description:
This range of capillary and rigid stem surface mounting thermostats operates on the principle of liquid expansion utilisiing a microswitch as the switching contact. IP54 Housing1000mmm Capillary tube1 x SPDT switching contact Switching point adjustable on the inside Differential of 3-4%Temperature range 0 → 100 and 20 → 150°C. Surface ...
Universal temperature controller for distributor installation.Settings dial with ...
Description:
Universal temperature controller for distributor installation.Settings dial with range limitation. The control unit and detector must be ordered separately.For mounting onto DIN rail.Changeover output.Applications: floor heating systems and enclosed area heating. ITR 3 temperature controller.