new immersion heater element not working

[HCM]

I have an immersion heater with two elements - the top one is on a timer so it can work as a boost - and it works very well.
The bottom one is wired directly to Economy 7 and worked well till about a month/6 weeks ago. An electrician then replaced the thermostat, and it worked again for a couple of weeks. He has now replaced the element - but it isn't working.
Does anyone have any ideas what the problem could be? I'd be grateful for any help.

 

[spacethegas]

has the stat gone to overheat ?

why cant the spark find the problem ?

 

[JohnD]

when an electrical part, which has recently been altered, goes wrong, a good point to look at is whether the alteration caused the problem. E.g. poor connection.

An immersion heater is very simple and has very few points of failure

wiring connections

thermostat

overheat stat

element

A new thermostat and element are unlikely to go wrong for ten years or so unless they have been damaged e.g. by careless handling. Cable doesn't go wrong unless it is damaged, overrloaded or badly terminated.

sometimes, working in a cramped airing cupboard, it is difficult to see the connections and get at them. But if they are on the front of the cylinder and the switch is easily accesible this should not be a problem.

How did you choose your electrician, and what can you tell us about his qualifications and skills?

 

[HCM]

The electrician comes well recommended via my niece, and is qualified. When he put in the new element (Monday), we waited till Tuesday am to see if the water had heated up overnight as it only runs on Economy 7- but it hadn't. I then adjusted the thermostat to a higher setting - but still nothing. He will certainly come back and try to fix it - but I was keen to see if any of you had any ideas I could suggest to him.

Many thanks for the suggestions - I'll make sure he goes through them.

 

[JohnD]

you have checked the fuse/MCB, haven't you?

 

[HCM]

I'm very wary of doing anything myself - but will make sure he does!
Many thanks!

 

[28moredun]

IS THE timeswitch AN HORSTMANN QUARTS. IF IT IS THE BOOST WILL WORK BUT THE OFF PEAK WILL NOT. IT IS A COMMON FAULT WITH THIS TIMESWITCH, TO CHECK your ELEMENT AND themostat.GET YOUR ELECTRICIAN TO OPEN THE timeswich AND SWOP connetion 5 WITH CONNECTION 4 AND swtch ON THE BOOST GIVE IT A HALF HOUR TO SEE IF THE WATER HAS STARTED TO WARM UP IF IT HAS THEN CHANGE THE TIMESWITCH

 

[Agile]

I would be very surprised if the electrician is very qualified or capable!

If he is unable to properly check something as simple as a two terminal circuit then there is something wrong.

Sometimes after transit the o/h stat will have tripped but this would be reset by the electrician during commission testing.

Please let us know what turns out to have been the problem.

Tony

 

[HCM]

It is working now - the thermostat was faulty.
Many many thanks everyone for their help and suggestions.