Immersion overheating...

[JonGill]

I replaced the stat, and the problem remains - new stat is "working" as I can hear it click on and off as the water in the tank cools.. It's a dual immersion, and on the old stat, the "bath" setting did not heat any water. Wall switch seems to be wired correctly. Bath setting now overheating the water as well!

Wondering if the brown 'live' to immersion should attach first to the OverHeating stat, then on to the thermostat, as it now does ?

A previous thread suggested that the stat may need to be rotated by 180 degrees, but not in this case - seems to be clicking at approx. the correct temperature.

Any ideas ? and thanks in advance

 

[RF Lighting]

Can you post a photo of your connections at the element?

Normally the stat switches the neutral on a dual element setup.

 

[JonGill]

Of course you are right.. stat on the neutral as you describe - photo not great but you can make out blue coming in to Over-ride, and re-set, on to stat and to the two coils... what do you think I should try next??

Untitled

• JonGill
• 17 Sep 2013
• 1

 

[PrenticeBoyofDerry]

Is this a vented or pressurised system.

 

[JonGill]

Vented I think - I could empty the tank by turning of water supply at rear of tank, not the mains supply.

System installed approx 30 yrs ago - tank and immersion replaced 2 yrs ago, with no major plumbing alterations. There is a hot water feed from a wood burning stove, flow controlled by a separate stat, so this should not effect the immersion.

 

[PrenticeBoyofDerry]

So you replaced the rod stat?
And the new rod stat is not working?

Was it over heating on the old rod stat? But was working previously to fault?

If so I guess you may have purchased a faulty rod stat.

What setting is the stats on?

 

[JBR]

Untitled

• JonGill
• 17 Sep 2013
• 1

I'm not trying to be funny here, but having seen so many out of focus photos on here can I make a helpful suggestion?

Hold the camera further away. These autofocus cameras are very good but have their limits, and if you're too close there's no way it's going to cope. If you move further back it may well not fill the screen but it will be in focus and produce a better image.

 

[JonGill]

old rod stat also allowed the water to overheat. Not sure if this immersion ever worked correctly since it was installed. I turned the new stat way down and it still faied to cut out the immersion, although as i rotate the temp. adjuster i can hear it click on and off at approx. the right temp. Photo was best ot 20 - distance restriction due to shelving... I blame my wife...

 

[bernardgreen]

The only way those immersions can heat the water beyond the setting of the thermo stat is if the blue and black are incorrectly wired at the switch.

If one of blue or black is connected to live and the other is connected to neutral then the immersions are in series between live and neutral and not controlled by the thermostat.

 

[JonGill]

Thanks bernard, I'll try that tonight....

 

[JonGill]

Swapped Blue and Black at the wall switch, and the problem is solved ! Kids still afraid of hot tap, but they'll learn as the winter closes in...
Thanks for all your help, Jon

 

[JohnW2]

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