Fixing electric immersion heater of hot water cylinder..

sujsuj

Newbie_John said:

I have had a similar one - Thermowatt, and all I needed to do is to press the reset button - inside under that black cover, similar for yours:
https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.teslauk.com/pdf/downloads/Resetting%20the%20TS%20Series%20Thermostat.pdf&ved=2ahUKEwjNxeaxjJCDAxUE0wIHHVypDYgQFnoECBgQAQ&usg=AOvVaw1sGFOm_eyi6rK34yXpgMZC

It needs little bit force to press it and it will click if that was the problem.

But if you take the cover off and see any burn marks, smell burn then may be worth replacing just the thermostat - simple ones are under £30.

I recently replaced my Thermowatt with Tesla Smart Thermostat:
https://www.unventedcomponentseurope.com/2-1-4-3-kw-350mm-incoloy-plastic-cover-plug-in-no-stat.html/?utm_source=Google Shopping&utm_campaign=Copy Unvented Components Europe&utm_medium=cpc&utm_term=484607&gclid=Cj0KCQiA7OqrBhD9ARIsAK3UXh1LCrJbmZhzboYbYcgzbtSiYFxxStKMz4ODhhfkHclSDYwwqzxDvqgaAkmSEALw_wcB

Anyway, all the above you can try without emptying the tank - hope it helps.

Looks like immersion heater reset did work after all. Thanks very much for this input.

I need to monitor some time to ensure immersion heater is working as today morning I switched on hot water using oil burner as well, so not 100% sure water is hot due to immersion heater. Is there any easy way to see this immersion heater is working..? I noticed..

(1) Light dim when the immersion heater is switched ON - Is this proof that immersion heater is working..?
(2) When I keep my ear close to Tank I can hear some sound like boiling water inside
(3) After keeping Heater switch ON for 30 minutes when I switched OFF I can see some spark with in the Switch

Above three indicates Immersion heater is working..?? Thanks

sujsuj

I am slightly confused which pipe need to be turned off if I need remove the immersion heater . (I will do this only if it is proved that immersion heater is no more working!)

Pipe connections with HOT (H) or COLD (C) pipe status is as below. I can see some confusion in labelling..Normally all hot pipe valves handles are BLACK  colour with Red band on it also labelled as Hot shower 1/2 etc. Cold pipe valves also  marked and got Dark BLUE handles But one pipe is labelled  as HOT Outlet connecting to bottom of the hot water tank but I think it is actually COLD Inlet from the water tank above..? I assume that is the one I need to turn off to keep water level bit low while removing the immersion heater.?

Please let me know. Thanks.

sujsuj

Also i checked thermostat from the immersion heater, it was hot but not sure if water was hot from Oil burner or  electric heater...

ThisIsWeird

Yes, it is almost certainly - 99.99999% - working.

ThisIsWeird

You can check the thermostat by turning it up and down - it should 'click', with all the symptoms you indicated before, at points which indicate the tank temp. Ie, the click point will change as the tank heats up.
Yes, it'll feel physically warm/hot due to the water temp.

ThisIsWeird

sujsuj said:

I don't understand that temp scale, in that it doesn't appear to have one. You would typically have it at a Legionnaire-killing ~65oC, but that isn't marked, unless it's the 6 o'clock position shown? I suggest finding the instructions for that model.
But it should 'click' crisply and audibly.

ThisIsWeird

sujsuj said:

I am slightly confused which pipe need to be turned off if I need remove the immersion heater . (I will do this only if it is proved that immersion heater is no more working!)

Pipe connections with HOT (H) or COLD (C) pipe status is as below. I can see some confusion in labelling..Normally all hot pipe valves handles are BLACK  colour with Red band on it also labelled as Hot shower 1/2 etc. Cold pipe valves also  marked and got Dark BLUE handles But one pipe is labelled  as HOT Outlet connecting to bottom of the hot water tank but I think it is actually COLD Inlet from the water tank above..? I assume that is the one I need to turn off to keep water level bit low while removing the immersion heater.?

Please let me know. Thanks.

The 'cold inlet' shown bottom-left in your sketch is almost certainly correct. If you trace that pipe up the back wall, which one is it? 
If you turn that lever off so that no more cold is fed to the tank, then the hot outlet to the taps - at the very top-middle - should stop flowing.
You'd then need to drain down a few litres to that the water level is just below the immersion fitting.

Albermarle

Regarding whether it is working or not, a look at your electricity meter should confirm that as they use quite a bit or power. Although not so easy to monitor with a Smart Meter as the old fashioned type, with the disc spinning around.

sujsuj

ThisIsWeird said:

sujsuj said:

I don't understand that temp scale, in that it doesn't appear to have one. You would typically have it at a Legionnaire-killing ~65oC, but that isn't marked, unless it's the 6 o'clock position shown? I suggest finding the instructions for that model.
But it should 'click' crisply and audibly.

+ and - marked on the dial. After max (near positive symbol) Red arrow need to rotate clockwise to reduce temperature.

ThisIsWeird

But what temps does it represent?