Strange Problem Immersion Heater Economy 7

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First of all let me say that you guys are doing a superb job. I spent about 7 hours looking through the forums here and almost solved my problem. Credit goes to the experts here.
The problem i have is with immersion water heater(Make is super seven). It has two filaments. One for the boost and one for Economy 7. My economy seven filament refused to work a few days ago. Going through the posts i took the following steps:

1. Checked all the fuses they were intact
2. Checked the thermostats with the multimeter they were fine as i swapped them around as well and the boost filament was working with the economy 7 stat.
3. Checked the economy 7 with the multimeter and it had the same resistance as the boost filament.
4. I plugged the Economy 7 filament into the boost filament connection and it works.

I am totally confused and dont know what to do next to get it working. :confused:
 
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Does voltage appear at the outlet in the wall beside the cylinder, when the timer has switched on at the meter?

You mention fuses, are these the rewirable type, or cartridges, or MCBs? I presume they are 15A or 16A?

Do you have two fusevoxes/consumer units (one for "economy night" and one for everything else?)

Do you have electric storage heaters, and are they working?

How long have you lived at this property, and when did the economy immersion last work?
 
JohnD said:
Does voltage appear at the outlet in the wall beside the cylinder, when the timer has switched on at the meter?

You mention fuses, are these the rewirable type, or cartridges, or MCBs? I presume they are 15A or 16A?

Do you have two fusevoxes/consumer units (one for "economy night" and one for everything else?)

Do you have electric storage heaters, and are they working?

How long have you lived at this property, and when did the economy immersion last work?

Well to be honest i have been waiting till maximum 12AM most nights for economy 7 to kick in. But unfortunately it hasent. I couldnt wait anymore as i have to wake up early to get to work. But have been suffering taking cold showers with 15 minute boost. Hopefully tonight i will have answer to your question as i am planning to stay awake till economy 7 kicks in. Having said that, as i mentioned ealier. I tested the voltage when i plugged the economy 7 fillament into boost and turned it on. It has voltage of 240V which was spot on. The fillament was working perfectly.

I have catridge fuses for the storage heaters. One CU for the rest. In the CU there is one MCB for water heating. Which never tripped.

Electric storage heaters are working perfectly fine.

I have lived in the property for more than a year and the immersion heater was working perfectly fine till a few days ago.

Just for your reference i am attaching the link to how my timer looks like
http://www.tlc-direct.co.uk/Products/HOE7Q.html
When i open the cover i have the option of 5 wires. If i swop 4 and 5. It changes top fillament to economy 7 and bottom filament to boost. In which case the bottom filament(Originally eco 7) works perfectly fine.
[/img]
 
The question I was puzzling over:

(1) Is your night immersion heater fed by a supply from the timed night-time meter? Your storage heaters will come from a timed supply that is actually only on during the economy period. This same timed supply could be used to feed the night time immersion, in which case there would be no voltage outside the economy period. In that case I would expect to see two supply cables going up to your airing cupboard.

(2) Alternatively, you may be paying economy rates for all your night-time electricity, even if it goes through any socket or lighting switch. In that case, there would only be one supply cable going to your airing cupboard, and you would be relying on the timer to switch on the bottom heater during the night.

Having looked at the picture of your Horstmann timer, I think you are on method (2). Is that right? Like this
ECON7DOUBLE.gif


In which case I would think that the timer settings are wrong or the timeswitch is faulty.

If you are having to shower in cold water, you might think about putting in a simple 20A switch while you order a new timeswitch or fix the old one. It does not need to be a fused switch if, as i understand, the immersion heater is on a dedicated circuit and has a 15A or 16A MCB in the consumer unit.

You could then turn on the switch when you go to bed, and the cylinder will be full of hot water by morning. There is an immersion heater switch available that will control two immersion heaters alternately (edited to say, i see that costs three times as much).
 
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Thanks John, I think you are right in assessing that its case 2. I guess its the problem with the timerswtich. But is there no way of judging that its definitely a problem with it. I mean if i can test it. Have you ever seen a similar timerswitch and explored the circuit. My gut feeling is that its the swtich inside which is clicked by mechanical rotation of the clock dial.
 
You could play with it on the kitchen table with a £5 multimeter, or a battery and bulb. Don't explore it using mains voltage!

It might well be something simple. Sometimes there are white plastic cogs inside, if one slips sideways on its shaft it stops engaging with the next gear wheel. i see a new timeswitch is quite expensive so it might be worth a try (a manual switch should be £5 or so retail, I would have thought). You mustn't have both elements on at the same time or you will overload your cable and trip the MCB
 
I agree with John, sounds like the E7 timer is kaput, I have swapped plenty of these over the years, about £60 for a new one, should fit straight on the old box with push connections
 
Thanks for all your help. I think i will see how i get on with the testing of the timerswitch. It saturday tomorrow so i might be taking a trip to DIY and Electric Stores. Any suggestions of a replacement timerswitch which is reliable and economical.
Thanks a lot once again.
 
I believe Horstmann is a good brand and a new one will probably plug straight onto the backing plate. Those things are expensive, so avoid anything from a budget maker, you don't want to be changing it again. there might be an electronic model available now. An Electrical or Plumbing supplier should give a good price, or Screwfix will send you one overnight like this http://www.screwfix.com/app/sfd/cat/pro.jsp?id=44419&ts=35690 but make sure the one you get is for two immersion elements. (check http://www.screwfix.com/app/sfd/cat/pro.jsp?id=44419&ts=35690#
 
Cheers guys. Thanks a lot for the help. Specially JohnD you are a star. I got the same horstmann timer switch through eBay. Cost me 24 quid BNIB. Installed it and its giving me hot water in the morning. Finally no more cold showers :D
 
I have economy 7 and believe I have this:

(1) Is your night immersion heater fed by a supply from the timed night-time meter? Your storage heaters will come from a timed supply that is actually only on during the economy period. This same timed supply could be used to feed the night time immersion, in which case there would be no voltage outside the ec

Read more: //www.diynot.com/forums/viewtopic.php?t=48029#ixzz1aVCrQ5CO

My question is where can I set this timer and the on / off ? I have a timer upstairs for manual override, which I have set up.

When I look at the downstairs meter I can't see a clock or any on / off switches to control. Problem being that the economy 7 seems to be coming on around 0200 and going to 0900 so I'd like to set the time on it.

I just can't find the timer anywhere. This is the 2nd house with economy 7 and I couldn't see the timer in my previous house either.

Where do they hide these pesky things and how can I set it correctly ? Various google searches just keep showing me timers to purchase, which I already have for the override.

Frustrating!
 
Where do they hide these pesky things and how can I set it correctly
In most installations, there isn't a timer - the E7 switching is radio controlled.
Even if it was an old installation with a mechanical clock, it will be DNO property and sealed so you wouldn't be able to change it anyway.
 
That will explain why I can't find it anywhere. So if I want to test if my E7 source works again, I have to wait until 00:00 to see if it comes on ?
 
It depends what system you've got as to when the E7 will switch on. IIRC it will vary with a radio teleswitch which will be switched on as demand in the area falls at some point in the night.

I'm sure one of the DNO chaps who post on here will be able to confirm.
 

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