twin immersion e7

[bridge]

please can anyone help. We have two switches on our immersion. The bottim works ok on E7 midnight-7am. However the top switch i guess is the boost but it doesnt work! Any ideas what we could check?

bridge

 

[Steve]

fuse in main fusebox? heater element burnt out? fuse in FCU next to immersion?

 

[TONY144]

recently had same problem on same set up the top heater was tripping mcb after approx 2-3 hours running but was not on rcd side of board as it would have tripped immediately.When tested found neutral to earth fault on heater element with insulation resistance tester. quite easy to replace just make sure you run enough water off before removing if side mounted heaters.

 

[andy]

i doubt a N-E fault would overload a circuit nd trip a breaker...

 

[crystal ball]

Switch the power off, take the cover off the heater, if it is a newish system it may have a resettable cut out built into the thermostat, have a good look at the connections to the thermostat and element, make sure they are all nice and tight.

To go further you will need a mutimeter to check the element is ok and the thermostat is working

 

[kai]

Often the thermostat rod fails (they last on average two to three years on an economy seven setup), but are cheap to replace - under a fiver each from TLC-direct.

http://www.tlc-direct.co.uk/Main_Index/Water_Heating_Index/Immersion_Heaters_2/index.html

Order five of them for around twenty one pounds, and they deliver free.

 

[JohnD]

If you know how old the immersion heater is, and the switch, and the wiring, that would give a clue.


Easiest thing to check is the MCB or fuse in the consumer unit. It should be 15Amp, probably marked in blue, and with "immersion heater" written above or below it.

There should not be a fuse in the switch by the immersion heater, but if there is, check it.

If there is a neon in the switch that will be a great help in knowing if current is on.

Old immersion heater switches sometimes wear out.

Cables seldom go wrong unless they are yanked or bashed.

Old thermostats always do .

 

[bridge]

Thanks for all your help, I will get my Dad to look at these tips.

Many thanks to all,

Bridge