Tesla (UK) Ltd

A. There are a number of causes of nuisance trip-outs, but often they can be cured simply by reducing the temperature setting on the thermostat. If this does not cure the problem or the resulting water temperature is not warm enough then the following should be considered: 1) The ambient temperature in the surrounding area of the immersion heater is too high. The airing cupboard door needs to have ventilation at the bottom to draw cooler air in and the roof or ceiling above the cylinder needs to be ventilated to take the hot air away. 2) The immersion heater is not fully immersed in water. This may happen due to the design of the cylinder which allows an air pocket to form below the immersion heater, or where there is a pump (e.g. power shower) and the cold-water feed is unable to maintain the water level. 3) The element has become heavily coated in limescale. The rate of limescale deposit is affected by the hardness of the water, the thermostat setting, and the amount of use, but excessive limescale has been seen in elements after less than 6 months. Reducing the temperature can help, but if you are in a hard water area we would recommend a titanium immersion heater. 4) There is a poor connection between the wiring and one of the terminals, either in the thermostat or on the immersion heater causing some arcing and sparking which is generating heat within the cap.

A. Possibly because the element is not the same model as the one that was removed. Try fitting a 14" element with a Double Bend.

A. No, you only really need to use the washer provided although PTFE tape may help if needed. PTFE tape is also a good lubricant and will help if the immersion heater is removed in the future. Also, make sure all sealing surfaces are clean before fitting the element and that no sealant get into the tank or on the element surface itself.

A. Try increasing the temperature that the thermostat is set to, but please ensure that the correct size of element has been fitted to the cylinder.

A. The new EN standard means that we cannot allow the upper limit of the control thermostat circuit to rise above 70 Degrees C as this will cause ambient temperature problems with nuisance trip outs due to interference with the secondary safety circuit.

A. That means that there is a potential leak through the thermostat pocket. Please contact us.

A. Invariably this is due to an electrical short. Ensure that the wires into the thermostat are securely in place and the retaining screws are suitably secured onto the bared copper wires but NOT over tightened.

A. Please call us for guidance.

A. Please call us for guidance.

A. Generally, this will be because the circuit breaker is of insufficient rating. Please ensure that the circuit breaker fitted has a minimum rating of 25amp and is on its own circuit and that nothing else is connected OR the element has a 'dead short'. Please consult a qualified electrician if in any doubt.

A. This will probably be a covering of limescale which has come from hard water and has effectively 'choked' the element. A new element of either Incoloy or Titanium should be refitted.

A. If the heater has failed prematurely it may be due to one of the following causes: (1) Excessive limescale build up caused failure (we advise titanium in hard or very hard water areas) (2) Element damaged due to not being fully immersed when activated - evidence of this is if the element of a copper immersion has turned a pink colour, or an incoloy or titanium immersion has turned a darker colour.

A. If an immersion heater with a copper thermostat pocket is fitted into a stainless steel cylinder then galvanic corrosion will erode the copper pocket and it will start leaking after a short period of time.