Dimplex Storage Heaters

[Musician]

I have a 4 element Dimplex XL storage heater; since turning it on this season, only one of the elements works. I have replaced the other 3, no joy, and only the element (any element) that 'sits' in one particular terminal block works. I've checked the power supply to each terminal block, all OK (and the resistance on all elements - all OK).
Any ideas?

 

[JB666]

Have you checked for any foreign body stuck in the terminal blocks?

Are the elements being clamped when you tighten the terminal block screws?

The elements are all linked so if one block has power all should, so...

 

[ricicle]

Have you connected the elements in correctly and securely into the ceramic terminal blocks. If the resistance of the heaters are correct and you have power to the terminals then they should get hot.
How have you checked the voltage at the blocks and is it with the heaters connected ?

What power rating are the elements and what were the resistance readings ?
Have you any way of carrying out a current test on the heaters ?

Please work safely and do not attempt anything that you are not competant to do.

 

[Musician]

The power rating on elements are, I believe, 850 watts; ohms across each element was 67.
With the heater on, the power reading was 245 volts across any/all terminals. All bricks etc were in place, so I couldn't check anything else.
I checked that terminal screws are tight.
For some reason, only one terminal is functioning....

 

[crystal ball]

Possibly one or both pins on the element has missed the terminal, can you give them a tug with long nose pliers to check, power off of course

 

[bernardgreen]

If you are measuring true 240 volts on the terminals that clamp onto the ends of the element when the element is fitted then the only reason is a no contact between the end of the element and the terminal block.

Corrosion / oxidation of the end of the element is one likely cause. Try cleaning them with a fine file, ( a nail file ) but be careful not to bend them or the seal will be damaged. The contact area of the terminal may also be corroded.

If there is "240" volts on the terminal without the element fitted and no voltage when the element in fitted then the fault is between the connector and the incoming supply to the heater. Possibly a poor joint in the wiring.

( a poor joint will allow through enough energy to show as 240 volts on a meter or neon screwdriver but not enough to put 240 volts onto the element )

 

[PrinceofDarkness]

This is a queer one, Musician.

So which particular one of the four terminal blocks is working? Logically, it should be the one on the extreme RHS thereby indicating that it's failing to supply the other three which are simply wired in parallel (in spite of your dubious reading of of 245V at every block).


Lucia.

 

[PrinceofDarkness]

Good grief! It appears that I'm not allowed by 'nanny' to use the word 'quear'.......

 

[Musician]

Thanks guys - problem solved - I think!
It appeared, heat-wise, that only 1 element was working, but that was the 'residue' from the other 3 failing - now replaced.
Having fitted a new thermostat, I thought there had to be something wrong with the new elements, or some strange circuit anomaly!
However, it transpires that I have been supplied with the wrong thermostat, which keeps cutting out.
Assuming the replacement solves the problem, it's 'over and out'![/quote]

 

[flameport]

The easiest way to check these heaters is to measure the resistance between L&N when the heater is fully assembled and the thermostat set at maximum. For 4 elements, the total resistance measured should be around 16 ohms.

 

[TicklyT]

Nobody nentioned the neutral connection to the elements. If the neutral is open circuit anywhere, the elements won't work, and you will see 240 Volts on the 'neutral' ends of the elements as well as the 'live' ends. The neutral ends should all be at or about 0 Volts.