Immersion heater wiring - help needed please

[ivrytwr3]

Hey all,

Before anybody says "get a qualified electrician" - i can't, i can't afford it and so i am asking for some help so we can hopefully have hot water for the winter!

The immersion heater we have heats the hot water only (a boiler does the central heating). The water has suddenly become scalding hot and i believe the thermostat(s) have gone and so i have bought replacements.

I have googled how to replace the thermostat and it looks straight forward as long as that is the problem - if it isn't then anything else is out of my capability and i will have to get in a professional. I have took a couple of pics, can someone tell me if the current thermostats are wired correctly?

Lastly, what do you recommend setting the ew thermostats too? The last ones were set at 60 each.

 

[vjsmarwick]

60-65 no less than 60 or it will not kill off liegoneers disease as for the rest can't help if we can't see the pics

 

[ivrytwr3]

lol, sorry, new member, need 6 posts.

 

[ivrytwr3]

 

[dim_bulb]

Its always cheaper and safer to get a spark in. As in the long run if you buy the wrong bits my opinion. Go to a plumbers merchant it's a long rod carefully pull it out and replace there not expensive if it actually is the? but don't take my word for that and would strongly advise getting in a electrician in and not carrying out the work yourself

 

[ivrytwr3]

i've already bought the parts on recommendation from a sparky at work:

2 x Sunvic VKL3201 7" Immersion Thermostat

to replace the 2 x backer bt - 7's already installed.

If someone could look at the wiring in the 2 x photos for me and advises if it's correct, i will replace tonight and report back in the morning if we have hot water or not.

----------

I would very much love to get a professional in, but when it's a choice between food or hot water, food wins.

 

[joe-sims]

the wiring is right but would again strongly agree that you should get a spark, there is no way of telling what has made it go wrong if it is that at all. odds are yes your right it is that but there are a lot of nasty things that can happen from this sort of thing past just the electrics but it

 

[snowhead]

Yes the existing wiring is correct, they wouldn't have worked correctly if it was wrong.

 

[ivrytwr3]

guys, i'm not questioning your judgement, that is why i am here, to ask the experts, but if you click on the top 2 x pictures they look wired different to me and i have no idea which is correct or which one has blown the thermostat.

one has the brown going ot the + and white to - and the other is reversed. Or is that just the temperature setting and it makes no difference which way the brown and white goes into the thermostat?

Sorry!

 

[joe-sims]

think of it just as a switch ... it don't make any difference witch way round it is live goes in switch live goes out ... if the tank is cold the switch is closed if the tank is hot it opens the switch ... simples

 

[ivrytwr3]

nice one - i was worried with brown to + in one and white to + in the other then maybe that is what blew the thermostat in the first place.

Right, i am going to change the thermostats now and will report back in the morning.


Thanks all.

 

[snowhead]

The + refers to the temperature setting, not the connection.

 

[ayjay]

the immersion at the bottom heats the whole cylinder
the top just a little bit at the top
is there a controller for this?
theres no way both stats would have gone kaphut at the same time, your probably only using one heater?
the stats need to be the correct lenghth to work properly

 

[ivrytwr3]

The bottom switch is Economy 7 and is left switched on all the time, the top switch is the boost (light switch type) which is rarely used.

The Backer ones i removed were 7" and i have removed and replaced both of them with another 7" one (the Backer ones are very old and also had no numbers on!)

 

[ivrytwr3]

ok, replaced both thermostats last night and set both to 60 degrees.

I switched on the top immersions switch and that kicked in straight away (and then tunred it off).

I woke up this morning and tried the taps and we have scalding hot water again

I will try turning down the temp on the thermostat, but i don't think it's that now as this is the 2nd set of thermostats this week