Immersion heater-no hot water

highspark · May 2, 2012

Call out today no hot water. Not familiar with immersion heaters but tested cable to bottom of immersion heater and got 230v and could hear it fizzing. However still no hot water. There was a second cable supplying the top half of immersion heater got no voltage at all across live and neutral.. Did IR and cables tested fine. The IH is fed from 16A mcb then into a timer. Is the top half on a timer? When I switch timer on still nothing across top cable. Any ideas? Element gone? Timer nackered

Tricksy · May 2, 2012

As others have said, test voltage to element, continuity across L-N to test continuity, IR L-E to check for leakage and clamp if you can to see what it is drawing.

egginyourface · May 2, 2012

I had similar call out today. I tested element with the old trusty fluke tester. L to N test gave me 1206 ohms. I gather this means element has gone....

I isolated at the spur and tested it whilst still connected.

jpm646 · May 3, 2012

Yes resistance is too high the element is ****ed m8 should b around 19 omz give or take

Edd · May 3, 2012

egginyourface said:
I had similar call out today. I tested element with the old trusty fluke tester. L to N test gave me 1206 ohms. I gather this means element has gone....

I isolated at the spur and tested it whilst still connected.

Elements gone. testing while still conected is fine as long as theres no neon on the double pole switch which will give a fause reading

highspark · May 3, 2012

Just been back. Bottom element gave me a reading of 1296 ohms.... So nackered? Top element gave me a reading of 17.9 ohms. However this is also not working as it should. It is wired in as the boost. When the timer is switched on manually (as customer would normally do) it is not working. Tested timer with voltage testers and when switched on it seems to be working fine. I have no idea why it is not operating. I've over rided the timer for the time being going straight from the mains and told customer to use circuit breaker as an isolation switch. Just waiting for phone call to see if it has warmed up

rich.250 · May 3, 2012

have you tested power to the element or where the cable has terminated?? still sounds like thermal trip to me

highspark · May 3, 2012

Why would it be thermal trip if it's working directly from an mcb now? Is the thermal trip in the timer?

rich.250 · May 3, 2012

Sorry mis read your post. I thought you didn't know it was heating the water even with the timer bypassed.

highspark · May 3, 2012

Yes since bypassed top element has started to work. Looks like a new timer and new element. Haven't really got the time to do it but... Got to be done!