Replacing an immersion heater thermostat with a cylinder thermostat.

[The Bedwetter]

I am having a problem with the thermostat that is located in an immersion heater element fitted to a direct HW cylinder (located in an attic). It operates properly for a few weeks and then for some reason the stat trips. As the element is 27” long I guess that sometimes it can be prone to bending slightly as it reaches peak temperature and makes contact with the thermostat.

Would it be possible to discard the element thermostat and replace it with a proper cylinder thermostat? This would appear to negate the ‘bending’ element problem but can anybody see any reason as to this arrangement not being acceptable?

Thanks for any advice.

 

[Reg Man]

Thought the thermostat was in a separate phial of the immersion heater element fitting. You can just unscrew the two contact wires and pull it from the phial. With the symptoms you have given, it sounds like the element is slightly pin holed and shorts out when it heats up. So change the whole element and might as well change the thermostat whilst your doing it.

 

[The Bedwetter]

Thanks for replying. Yes, the thermostat is in separate phial and I have tried replacing it on several occasions but, at some stage, regardless what thermostat is installed, it will trip. Hence my question about the bending element making contact with the sheathed section that houses the thermostat. Changing this type of stat for a proper cylinder type might perhaps deal with this issue.

You say the element could be pin-holed. Would this be likely on an element only 7 or 8 months old? It is an Incalloy type which I thought were supposed to be well protected.

 

[Leo21]

The new ones are carp. I've had to replace new ones quite a lot. Not sure if anyone makes a decent one anymore.

 

[PlumbBobBob]

a cylinder stat is completely different from an immersion stat, wired differently and operating differently. you cannot just substitute one for the other.

 

[jtsplumbing]

Incalloy immersion heaters are usely recommended for hard water area's, I cant see how you are bending the element to such an extent that it is touching the part that holds the temperature sensor ! as a Direct cylinder has got nothing else inside that will interfere with the fitting of a 27" heater ! If your cylinder is in the attic where is the cold water storage tank that supplies it ? or is it a case that you are trying to fit a 27" heater in a Fortic cylinder ??

 

[AWheating]

a normal cylinder stat does not have a non self resetting cut out, so no you cant change one directly for the other.

 

[Dotty]

a cylinder stat is completely different from an immersion stat, wired differently and operating differently. you cannot just substitute one for the other.

a normal cylinder stat does not have a non self resetting cut out, so no you cant change one directly for the other.

:iagree:

 

[AWheating]

the current would be totally different also, cant see a cylinder stat being designed to take the amps. It would need some simple to eletronics to diy it at a guess. It would not be advisable imo.

 

[kay-jay]

A cylinder stat is designed for indirect heat ie shutting a boiler down when heat satisfied.
A direct heat 3kw electrical immersion element relies on its own correctly rated stat. Crossing the two is likely to end in tears.....and an electrical fire

 

[The Bedwetter]

Jtsplumbing: The CW cistern is adjacent to the HW cylinder. No, it is not a Forbic.

Right then, guys, that’s clear. It is the case, then, that a cylinder thermostat is entirely incompatible with controlling an immersion heater. Well I certainly shall not be pursuing that path, then. Thanks.

Why is it, though, that a simple heating element is such an unreliable item these days? I am aware of elements that have lasted as long as 15 years or so. This, admittedly, was going back a while but why should there be such a marked deterioration in present day quality?

If anybody could recommend a element manufacturer that they know to be of better quality it would be much appreciated.

Thanks, again. :teeth_smile:

 

[kirkgas]

Jtsplumbing: The CW cistern is adjacent to the HW cylinder. No, it is not a Forbic.

Right then, guys, that’s clear. It is the case, then, that a cylinder thermostat is entirely incompatible with controlling an immersion heater. Well I certainly shall not be pursuing that path, then. Thanks.

Why is it, though, that a simple heating element is such an unreliable item these days? I am aware of elements that have lasted as long as 15 years or so. This, admittedly, was going back a while but why should there be such a marked deterioration in present day quality?

If anybody could recommend a element manufacturer that they know to be of better quality it would be much appreciated.

Thanks, again. :teeth_smile:

the simple answer to a reduction in quality is build quality related to the price we want to pay now, there are too many cheap imports of things now that is driving the higher quality ones out the game

 

[Worcester]

Not the cheapest on the market: Homepage - Backer Electric

 

[kay-jay]

Not the cheapest on the market: Homepage - Backer Electric

good stuff that backer. i use backer elements for boiling the wort when i make beer

 

[Leo21]

good stuff that backer. i use backer elements for boiling the wort when i make beer

You cant get a better recommendation than that!

 

[The Bedwetter]

You cant get a better recommendation than that!

Yes, I’d be right up for letting Kay-Jay road test the element with a bit of wort boiling. :teeth_smile:

I have checked the Backer website and there appears to be three different grades: the Copper Sheath range approx £20; the Anti-corrosive range approx £25-30 and the Titanium Sheath range approx £50. I assume everyone would agree that the Titanium is the way to go? I am in the London area so we do have pretty hard water.


(There is also a range called the Low Watts Density anti-corrosive range but I am unable to find anything available on the web).