Twin Immersion Boiler Stopped Working :(

A week before Christmas I noticed my hot water ran out a lot quicker than normal. I didn't think nothing of it then but the next day in the shower it was just pure cold water. I checked the fuse, which is fine. I'm running on a hortsmann electric 7 with a twin immersion range tribune boiler. This was already installed in the apartment which is about 5 years old.

When I first moved in I would just turn the boost on to heat the water. Normal timer didn't work for some reason. So I put it on timed boost to turn on around 1am for an hour. This would give me enough hot water for the shower and washing dishes when I got back from work.

Anyway, after researching I bought a multimeter. I checked for continuity on the actual immersion and was getting about 17-18 ohms which is good. So I pulled out the thermostats. They are called Thermowatt rts-3. I checked for resistance across the contacts and it was open. Then I bought two new stats which turned up last week (only available online). Yes I've been showering daily with cold water since it went bust.

I then checked the new stats for continuity and they were both open! Tried the reset button and turning the button but nothing. Hmmm. I installed them anyway wired it all up and nope still not working. No boost no timer. Wouldn't the boost button light up anyway even if the stat/immersion has failed to show that it's putting power through? Now I'm stumped. The new stats look brand new but show no continuity. Am I doing it wrong? I've just wasted £40 on these if it wasn't the stats.

New unit? Check for voltage?

It's just getting irritating having to shower with cold water now.

Appreciate the help.

Thanks

When you test the stats you should get a reading of 0.00 or a reading very close to 0.00 with the stat "cold" ---- open circuit on ohms will show something like "--.--" or "O/C"

Are you aware that on E7 the 'normal' timer will only come on over night? The 'boost' is 24 hr for you to use as a top up if you need it.

The bottom element will be the E7 one that will heat your whole tank when electricity is cheaper. The boost is the element about half way up the tank.

Shall I ring a couple of electricians and get this sorted ASAP..... nah, I'll buy a multimeter even though I have no idea what to do with it and hope for the best, can't be that hard, it's not like electricity is dangerous or owt. Now I'll randomly order some parts so that I have now probably spent pretty much the price of a callout and still haven't got anywhere.

NozSpark said:

When you test the stats you should get a reading of 0.00 or a reading very close to 0.00 with the stat "cold" ---- open circuit on ohms will show something like "--.--" or "O/C"

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  The figure just stays on 1 even at the lowest ohm setting on the multimeter. But I know the multimeter is working as it shows the immersion element is find.

Essex1 said:

Are you aware that on E7 the 'normal' timer will only come on over night? The 'boost' is 24 hr for you to use as a top up if you need it.

The bottom element will be the E7 one that will heat your whole tank when electricity is cheaper. The boost is the element about half way up the tank.

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Yes. I've set the timer to come on without boost at about 2am but it doesn't work at all which lead me to believe that now both my stats have failed.

What does the the meter say when you touch both the probes together?

Lurch said:

Shall I ring a couple of electricians and get this sorted ASAP..... nah, I'll buy a multimeter even though I have no idea what to do with it and hope for the best, can't be that hard, it's not like electricity is dangerous or owt. Now I'll randomly order some parts so that I have now probably spent pretty much the price of a callout and still haven't got anywhere.

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Lol true. I did ring around but I'm getting ridiculous quotes. And some don't even reply back. I thought it would be good to learn something in the process, buy the parts myself and have a go. I've always done that before. I can just return the stats but want to make sure they are not at fault.

NozSpark said:

What does the the meter say when you touch both the probes together?

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Shows 0.

ImsoCold said:

Lol true. I did ring around but I'm getting ridiculous quotes. And some don't even reply back. I thought it would be good to learn something in the process, buy the parts myself and have a go. I've always done that before. I can just return the stats but want to make sure they are not at fault.

Shows 0.

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You cannot expect an electrician to give you a quote to find and rectify a fault when they don't know what is wrong.... It could be something as simple & cheap as a blown fuse or something much more expensive like your Horstman E7 timeclock or even a faulty element which would necessitate a drain down of the cylinder

NozSpark said:

You cannot expect an electrician to give you a quote to find and rectify a fault when they don't know what is wrong.... It could be something as simple & cheap as a blown fuse or something much more expensive like your Horstman E7 timeclock or even a faulty element which would necessitate a drain down of the cylinder

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It's fused from a wall switch that has a light on it, means its good. I'm sure the element is fine as well given the readings?

I'm just trying to fault find myself.

I'll have to take a day off work to arrange an for an electrician to come down.

ImsoCold said:

It's fused from a wall switch that has a light on it, means its good Not necessarily. I'm sure the element is fine as well given the readings ? Again, not necessarily

I'm just trying to fault find myself. Although you have a multimeter, you do not have the correct test equipment to fault find

I'll have to take a day off work to arrange an for an electrician to come down. It seems that way

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Mine in Red

ImsoCold said:

Lol true. I did ring around but I'm getting ridiculous quotes. And some don't even reply back. I thought it would be good to learn something in the process, buy the parts myself and have a go. I've always done that before. I can just return the stats but want to make sure they are not at fault.

Click to expand...

Yes, but you do not know how to use a multimeter. Having a random prod about in something you have absolutely no idea about when it can kill you is not a good way to learn.

ImsoCold said:

Shows 0.

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My point exactly.

ImsoCold said:

It's fused from a wall switch that has a light on it, means its good. I'm sure the element is fine as well given the readings?

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Not necessarily, it gives an indication that it might be OK but that is it. The limited "testing" you have done so far proves nothing conclusively.

Given that you do not even know how it works or how E7 works I would imagine that you could be dead before the fault is found.

Fault finding does take some specialist knowledge and equipment. The fault is between the switch and the element. So it could be the cable, timer, loose connection, stat, element or a combination. Then you have the issue on whether any repair you do carry out is safe.

This really is a 1 hour job to trace this fault and with the exception of an element fault a 1 hour fix.

The inappropriate Instrument in the wrong hands can be very dangerous.

I know a bloke who heard the expression. "Line earth loop is 0.7 ohms"

So He tried it for himself with a multimeter set to ohms

It did NOT end as he expected it to

Lurch said:

Shall I ring a couple of electricians and get this sorted ASAP..... nah, I'll buy a multimeter even though I have no idea what to do with it and hope for the best, can't be that hard, it's not like electricity is dangerous or owt. Now I'll randomly order some parts so that I have now probably spent pretty much the price of a callout and still haven't got anywhere.

Click to expand...

I reckon in an hour or two I could have metered out the cable imm heaters, thermostats, AND probably put a temp 230v on to see if the water starts to heat.

and thus deduced if or what parts may or may not be needed...

Guinness

I assume this is the thermostat you have http://www.thermowatt.com/en/product/122

There are two spade terminals on the immersion heater and two corresponding terminals on the back of the thermostat,

I presume you have disconnected the cable (making a note of how it was connected first) and pulled the old thermostat off.

Measure the resistance between the two terminals of the immersion heater, you should get about 19 ohms

Now plug the new thermostat onto the heater. Take care, it is very easy for one or other of the spade terminals to miss. Once you are sure it's on properly, measure the resistance between the two terminals on the front of the thermostat (before you re connect the wires to them)  you should see the same resistance about 19 ohms.

If you don't, and you have checked for the reset button being tripped, then you have faulty thermostats so no point going any further until you get another replacement.

If you post your approximate location it may be that one of the decent electricians on this forum could come and fix it for you.

I've plugged in both the new and old stats and I'm getting a reading of about 17.6 ohms when I touch the wire connection points. But surely if the stats were good then I should be able to get a reading if I connect it on the spades when they are removed?

No.... The switch usually only works between the L terminal and the L spade

ImsoCold said:

I've plugged in both the new and old stats and I'm getting a reading of about 17.6 ohms when I touch the wire connection points. But surely if the stats were good then I should be able to get a reading if I connect it on the spades when they are removed?

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So the stats and your heaters are good. So it is some other fault.

Time to get an electrician.

Could still have an IR fault....

NozSpark said:

Could still have an IR fault....

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He got a multimeter, He is under the impression he now knows more than a forum of electricians. Don't think your feeble attempt at logic and sense is going to register on his higher intellect scale.