Immersion timers keep failing

[Subby]

Hi all .
Have been to change an immersion timer for a Santon premier to210e invented cylinder.
This cylinder has a 3kw immersion element (240v)
I have fitted two different timers to replace the original but they have both failed after a few days of operating.
After a few days u no longer get 240v at the switched live terminal in the timer when the timer is calling for heat. This happened to both the timers I fitted (both 16A load rating) one mechanical from the electric merchants, one lap digital one from screwfix.
Why are the timers failing? The element works fine when I link out the timer. Thanks in advance.

 

[7029 dave]

Horstmann I used found them good quality.

 

[sparkdog]

Maybe you could fit a contactor.

 

[freddo]

Test the element including a load test.

Yea do this, had one once that was all split open and part of the element was touching the metal sheath so it was drawing more current than it should, but nothing excessive, around 15.5A IIRC no RCD on circuit. That one ----ed the timer which was the reason for the callout.
Any time I do any work on an immersion heater I always carry out an insulation resistance test, current test with clamp meter and earth fault loop impedance test.

 

[Subby]

Thanks. I know it seems that the timers I bought were of low quality but it seems too much of a Co incidence that 3 have gone in the space of a couple of weeks.
Will carry out the tests you mentioned thanks

 

[telectrix]

if your water has a high calcium carbonate content (limescale)be a good idea to fit a stainless element.