Immersion not heating

[southcoastboile]

Really strange fault with this one.

i went out to a twin immersion cylinder. 2 different fuse spurs. One had power the other didn't so I assume one was on economy 7 and the other is a backup.

the backup one is the only one they say they ever use and the economy 7 one is always off. I had power in and out of the stat and I could hear a slight hiss as if it was working but it was not getting hot.

I swapped the cables over in the hope that the lower immersion that was on economy 7 was okay and that it would give them hot water. Got a call a couple of hours later to say it still wasn't getting hot. I suspected both impressions were faulty.

i sent an engineer back to replace both of them and she again called to say it's still not getting hot.

i asked the engineer if there was any scale and he said a bit in the bottom but nothing much. The hot water pressure is also okay.

im completely out of ideas on this one now and going back tomorrow.

anyone got any idea why it might not be getting hot?

 

[AWheating]

check the resistance of the heaters coil, check you have 230v on the coil, it should get warm, if all is well get a sparks in to check the wiring. Watch out for bad stats, they seem to be very poor quality in most heaters.

has it work ok before? have then had a new electric meter fitted?

 

[townfanjon]

Is there 230/240 volts to the stat, rather than just a lit neon on a tester

 

[steadyon]

Resistance should be about 18 ohms, +- 2 ohms. Tested with all power removed.