The Tesla Resettable Dual Safety Thermostat is a genuine manufacturer replacement rod thermostat for the full Tesla immersion heater range, allowing a faulty or nuisance-tripping thermostat to be replaced without removing the element itself. Each thermostat combines adjustable temperature control with a manual-reset over-temperature safety cut-out.
Available in three stem lengths — 7", 11" and 18" — matched to the thermostat pocket depth of the corresponding immersion heater length. Select the correct code below based on the stem length required for your installation.
Please Note: Always match the thermostat stem length to the thermostat pocket length of your existing immersion heater, not the overall element length. Fitting an incorrectly sized thermostat can prevent the sensing bulb from reaching operating depth in the pocket.
Resettable Dual Safety Function
Combines adjustable temperature control with a secondary manual-reset over-temperature cut-out, meeting the secondary protection requirement built into the EN 60335-2-73 standard.
Snap-Disc Reset Mechanism
The secondary safety protection uses a bi-metallic snap disc beneath the thermostat head. In an overheat event, the disc snaps to activate a square reset button, cutting the electrical circuit until manually reset.
Matched Stem Lengths for Every Element
Stem lengths of 7", 11" and 18" correspond directly to the thermostat pocket lengths used across the standard Tesla immersion heater range, ensuring accurate temperature sensing depth.
High Current Rating for Reliable Switching
Rated at 15A, comfortably exceeding the current draw of a standard 3kW/240V immersion heater element.
Reduces Nuisance Trip-Outs
Many reported nuisance trip-outs are resolved simply by reducing the thermostat temperature setting rather than requiring element replacement — a genuine Tesla replacement thermostat restores correct calibrated operation.
Simple Rod-Type Fitting
Screws directly into the element's existing thermostat pocket, allowing like-for-like replacement without disturbing the element or the cylinder boss seal.
| General Specification |
| Manufacturer |
Tesla UK Ltd, Sutton Coldfield, West Midlands |
| Approval Standard |
EN 60335-2-73 (BS EN 60335-2-73) |
| Type |
Resettable dual safety rod thermostat |
| Reset Mechanism |
Bi-metallic snap disc; manual reset via square button on thermostat face |
| Factory Pre-Set Temperature |
60°C |
| Safety Cut-Out Temperature |
85°C |
| Current Rating |
15A |
| Voltage |
240V AC |
| Code |
Stem Length |
Adjustable Range |
Factory Pre-Set |
Cut-Out Temp |
Current Rating |
| TS220 |
7" |
10-70°C |
60°C |
85°C |
15A |
| TS225 |
11" |
25-70°C |
60°C |
85°C |
15A |
| TS230 |
18" |
20-70°C |
60°C |
85°C |
15A |
Important Safety Information: This is a mains-voltage electrical replacement part. Thermostat replacement work must only be carried out with the power isolated at the mains and, after installation, the wiring must be tested by a registered electrician or Part P competent person. The immersion heater must be fully immersed in water before power is reapplied.
Which thermostat length do I need?
Match the stem length to your existing thermostat pocket, not the overall element length: use 7" (TS220) for 11"-14" heaters, 11" (TS225) for 18"-23" heaters, and 18" (TS230) for 27"-36" heaters.
My immersion heater keeps tripping out. Will a new thermostat fix this?
Nuisance trip-outs are often resolved by reducing the thermostat's temperature setting. If this does not resolve the issue, a worn or miscalibrated thermostat may be the cause, and fitting a genuine Tesla replacement is the recommended next step.
Can I replace just the thermostat without replacing the whole element?
Yes — that is the purpose of this range. Provided the element itself is functioning correctly, the thermostat can be replaced independently using the matching stem-length code from the table above.
What does the manual-reset safety cut-out do?
It is a secondary protection device using a bi-metallic snap disc. If the system overheats beyond the cut-out temperature, the disc activates a reset button on the thermostat face, cutting power to the element until the button is manually pressed again.
What current rating do these thermostats have?
All three variants (TS220, TS225, TS230) are rated at 15A, which comfortably exceeds the current draw of a standard 3kW/240V immersion heater element.
