Economy 7 Water Heater element broken

GibbsRule_No3

My water heater has two elements, the E7 part and a booster for heating for when I come home from holiday, say. The E7 element has broken three times last year, once the entire tank was drained and new elements were put in both parts. The E7 goes off at 8.40am at this time of year 9.40 during the summer. Every time the plumber/electrician comes the E7 is of course off, so my question is, other than them coming between 8 - 8.40 as I have asked my landlord (housing association)to do, is there anyway they can check the electricity to that E7 element?

jk0

Yes. Using an ohm meter. A professional electrician should be able to test it okay. A healthy immersion heater should have a resistance of about 18 ohms. Anything much higher or lower means it needs replacing.

knightstyle

The electricity supply is set to certain standards and is unlikely to have an effect on the immersion heater failing early.
How long is it on for each day? Try reducing the time.
What temperature is the stat set at, try reducing the temperature.
What type of replacement immersion heater was used? Next time insist on a titanium coated one.
All the above will help the new one last longer.
As for testing, usually they fail due to corrosion and an insulation test will confirm this.

nofoollikeold

Most elements now have 2 thermostats, the one you can use to set the water temperature and an over heat thermostat.
If the over heat thermostat trips, it does not reset itself, you have to do it by removing the cover and pressing in a little plastic button, usually about 3 mm in diameter and red or black. Sometimes a pin or paper clip is needed if the button is recessed.
If the water temperature thermostat is set too high, it can allow the over heat one to trigger.
Testing both thermostats and the element should be well within the capabilities of an electrician, but check the over heat button first to see if an electrician is needed. But you will need to remove the cover, and this exposes electrical wiring and connections at potentially mains voltage. Make sure you know what you are doing before removing the cover, switch off both elements and make sure you do it in non-operational times for E7.

GibbsRule_No3

knightstyle wrote: »

The electricity supply is set to certain standards and is unlikely to have an effect on the immersion heater failing early.
How long is it on for each day? Try reducing the time.
What temperature is the stat set at, try reducing the temperature.
What type of replacement immersion heater was used? Next time insist on a titanium coated one.
All the above will help the new one last longer.
As for testing, usually they fail due to corrosion and an insulation test will confirm this.

It is on for the 7 hours that E7 is on for overnight. Strangely and EDF have difficulty believing me when I have the conversation every time, the 7 hours are not continuous. At present it comes on around 11.40, goes off sometime during the night for an hour, I think around 4ish and then comes back on, before going off at 8.40 On the meter box it gives two times that don't really tie in with what does actually happen. The two new elements and drain happened in April last year, the November call back just replaced a tiny brown wire that was completely exposed with green wires showing, so the element itself was probably okay this time, hence me wondering if it is more an electrical problem. When the tank was drained the plumber suggested it should be removed and a new one installed if it happened again, the build up of gunge inside was remarkable, hard water area of course, tank original from the 70's when the property was built. Will see what they say in the morning. Just getting my little ducks in a row for the conversation.

getmore4less

Hard water area all the scale in the bottom of tank will need removing as well

Can be done through the emersion hole.

GibbsRule_No3

nofoollikeold wrote: »

Most elements now have 2 thermostats, the one you can use to set the water temperature and an over heat thermostat.
If the over heat thermostat trips, it does not reset itself, you have to do it by removing the cover and pressing in a little plastic button, usually about 3 mm in diameter and red or black. Sometimes a pin or paper clip is needed if the button is recessed.
If the water temperature thermostat is set too high, it can allow the over heat one to trigger.
Testing both thermostats and the element should be well within the capabilities of an electrician, but check the over heat button first to see if an electrician is needed. But you will need to remove the cover, and this exposes electrical wiring and connections at potentially mains voltage. Make sure you know what you are doing before removing the cover, switch off both elements and make sure you do it in non-operational times for E7.

It was this that corrected the fault. I did get the electrician to turn the thermostat down even more than the last time. Easier to use less cold water in the mixer shower tap than have the water so hot that it trips the switch. So will see what happens tomorrow morning. I did ask if I could do it, if it happened again and got the stock answer to cover himself "that it did expose wires, but if I had the switch off, I could try it if I felt comfortable doing it".:T:T