Old Electric water heater with 1 heating element and 2 thermostats

[thomasbroggi]

Hi All,

I have an old immersion water heater that only seems to have 1 heating elements at the bottom, but for some reason it has 2 thermostats.

The thermostats seem to be connected in series. Now one of the 2 (the red one) keeps tripping and needing reset so I was thinking to bypass it and only use the other one.

Am I missing something here, why would there be 2 thermostats in series? I'm also a bit confused and scared with the un-isulated wire connecting the 2!

I attach a picture of what I have

Thanks!

 

[polesapart]

Set the blue stat lower.

Under no circumstances attempt to link out or bypass the safety overheat stat.

 

[Jurassicspark]

Regarding the naked wire running in series with the thermostats, replace it with a short piece of 13A wire. A bit of slack and that wire will touch the body of the thermostat.

 

[polesapart]

Regarding the naked wire running in series with the thermostats, replace it with a short piece of 13A wire. A bit of slack and that wire will touch the body of the thermostat.

Ferkin heck -missed that!

 

[CountryFan]

Zooming in, looks like there is or has been moisture

 

[thomasbroggi]

Thank you all for your advice. I will replace the cable, not sure why it was installed like that!

For my understanding,
- what is the difference between the blue and the red thermostats and why should the blue be set lower to stop the red from tripping and needing a reset?
- why are there 2 thermostats rather than 1 only, like in other immersion heaters?

About the moisture, there isn't any as of now, not sure if those are old signs.

Thanks again!

 

[Jurassicspark]

Thank you all for your advice. I will replace the cable, not sure why it was installed like that!

For my understanding,
- what is the difference between the blue and the red thermostats and why should the blue be set lower to stop the red from tripping and needing a reset?

If the temp on the blue is set at 70C and the red is set at 60c the red one will trip first and require manual resetting. (Just for understanding).

- why are there 2 thermostats rather than 1 only, like in other immersion heaters?

If one fails to turn off the immersion heater the other one will cut the supply to it. It will require a manual reset to get it back working again. It's for your safety. Do not bridge any of the thermostats.

I think pre 2009 ones only had one thermostat. From the top of my head so possibly incorrect!

 

[thomasbroggi]

makes sense!
thank you Jurassicspark