Some Views On Fault Finding Procedures.

[pewe]

NozSpark

I don't have enough technical expertise to disagree with you, but did you read what Horstmann said when I spoke to them?

They said that a spike from a faulty element appeared to have destroyed both 'circuits' - they never used the word 'switches'.

The switches may still be intact (I haven't stripped it down to see) but sufficient components were damaged to the point where the timer will not work , 

I took the top cover off the thermostat (it was loose and just slid off) and could see that the contacts were welded.

 

[SLIPSHOD & SLAPDASH]

I changed one of these timers last Christmas which had blown due to the same fault, circuit board was blackend in areas after the element    gave up . Customer said it had been replaced about 6- 7 years ago along with the immersion. 

Using one of these timers is normal procedure when you have a duel rate meter, I doubt its 'E7'  I think the  Horstmann part cost  a few pounds less than £70

 

[pewe]

By E7 I meant it was a controller for Economy 7 use - although my mother has Economy 10. 

A Sangamo Dual Flexi with multiple programmes would probably be a more flexible solution for her economy 10, but at her age she hates anything 'new and unfamiliar'.

I bought the replacement at Screwfix  - the only place locally that sells them - for £69.99.

 

[SPECIAL LOCATION]

Re the heater damaging the controller bit.....

assuming its something such as one of these type of beasties..

http://www.free-instruction-manuals.com/pdf/pa_457948.pdf

From the middle of page 1, Horstmans own words state:-

"In some cases immersion heater failure can damage the economy 7 quartz"

I would be interested to know what supply circuit and fusing and or RCD (if fitted) this arrangement is fed from?

The company who supposedly came out to fix the fault are incompetent buffoons IMHO!!!

 

[ProDave]

By E7 I meant it was a controller for Economy 7 use - although my mother has Economy 10. 

A Sangamo Dual Flexi with multiple programmes would probably be a more flexible solution for her economy 10, but at her age she hates anything 'new and unfamiliar'.

I bought the replacement at Screwfix  - the only place locally that sells them - for £69.99.

I know you don't want to change things now, but really what you have I think is a poor solution.

It's way too complicated and introduces an expensive thing to go wrong.

ALL that is needed is a feed from the off peak CU to the bottom immersion heater via a switch (which is just for maintenance or when you go away on holiday). That will give you hot water at the cheap rate overnight and a mid day boost as you are on economy 10, something you are missing out on now.  Why install your own timer when the DNO provided one for you?

Then in addition to that one of the simpler timers to give a boost to the top heater if really needed.

 

[pewe]

@Special Location

That's the beastie.

The immersions are connected directly to the controller (as per the details shown in the booklet you linked to).

The controller is wired directly back to the fuse box which has the 'normal' arrangement of individual trip fuses for each circuit and a master input trip.

The heating circuit is on its own fuse - I'm not sure of the value of the heating fuse nor the main one.

A couple of posts have mentioned an RCD. If that implies that there should be some other form of safety cut out in the circuit - there isn't one. This would beg the question as to why the contractor (same company) did not advise that one should be fitted when they replaced the controller 7 years ago - although views on safety may have been different then.

@Prodave.

Thanks for the thought, but at her age, like a lot of older folks, Mum is very wary of any new change - and can get a bit confused with new things.

Although I agree with you that there are other solutions that may be better or less expensive, she has had this system since she moved in to the flat 12 years ago and is used to it. 

 

[ProDave]

With the age of the wiring installation, there was no requirement at that time for an RCD feeding an immersion heater, so I would not worry about the lack of one.

Hopefully now it's sorted with a new heater and a new timer so you should get another 12 years or more without worry.

 

[pewe]

Hopefully the installation will outlast her stay in the flat.

Although she has not used it for some time - and probably never will - I guess I should replace the top immersion when I have some time.

Thanks for your input guys.

 

[SLIPSHOD & SLAPDASH]

I know you don't want to change things now, but really what you have I think is a poor solution.

It's way too complicated and introduces an expensive thing to go wrong.

ALL that is needed is a feed from the off peak CU to the bottom immersion heater via a switch (which is just for maintenance or when you go away on holiday). That will give you hot water at the cheap rate overnight and a mid day boost as you are on economy 10, something you are missing out on now.  Why install your own timer when the DNO provided one for you?

Then in addition to that one of the simpler timers to give a boost to the top heater if really needed.

As i mentioned earlier i dont think this is a set up like that, but a duel rate meter with one consumer unit & why this type of timer is used. In this case its on E10

 

[pewe]

You are right SS - Mum has one supply from a single dual rate meter.

On the other hand, in our house (an old cottage) we still have 2 meters, A standard meter and the old 'Off Peak' meter.

We were going to change to economy 10 but calculated that it is cheaper to leave the Off Peak meter.

Our setup consists of one of these

http://www.horstmann.co.uk/products/heating-and-hot-water-controls/boost-controls/bx2000

This has 2 feeds, one from the standard meter and one from the off-peak.

As the off-peak is only live when there is a Standard feed present, we put a timer (with manual override) on the standard feed so it only comes on between 8am and 11pm (so we can boost if needed, and 5am and 7 am for heating the water over night.

This suits our needs admirably, but the controller is totally different to mums E7 quartz.   

PS - we didn't pay £80 for the BX2000, I got it off ebay for £8 a few years ago when there was an abundance of second hand on the market.

 

[ProDave]

Yes but even if it's just 1 dual rate meter, there will be a switched off peak output from the meter that's only on during the off peak rate.

Even if there isn't an off peak CU at the moment, it would be simple to add one.

These days the time switch and dual rate meter are all in one unit. In the past the time switch was a separate item.

 

[Phoenix]

Not always the case P.D.

I have a dual rate meter that has no provision for connecting an off peak board, it doesn't even look like there is provision to connect a switch wire in order to work a contactor for off peak loads.

I have an off peak tarriff, I run  dishwasher and tumble dryer during off peak hours, and have my morning shower on them too. All my DHW is from a gas combi boiler

Its one of these: http://www.electricmetersales.co.uk/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/images-1_1_9/www.electricmetersales.co.uk-AMPY-5254E-32.png

I think this is one of those things thats dependant on area/supplier and what was in before. In my case there was probably just a single rate mechanical meter in before with no separate timeswitch, and when it was swapped out, this gave the possibility of going either a single rate or a E7 tarriff, so more functional than was there before. An installation that needed it would have got a meter with a contactor controlled output

 

[ProDave]

Well you live and learn. I have never seen a dual rate meter without a switched output. Perhaps as you say it's DNO dependent, and I have only ever worked in SSE land.

I will admit to being confused the first time I saw the all in one jobbies with the time switch and contactor all in the same box as the meter

 

[pewe]

Mums fuse box has to sections using different mains fuses.

The meter box has split tails feeding the two sides of the fuse box.

One is for her ring main, immersion, cooker, lights etc and has power 24 hours, the other is for her storage radiators and only has power during the off peak periods (E10 hours)

 

[ProDave]

One is for her ring main, immersion, cooker, lights etc and has power 24 hours, the other is for her storage radiators and only has power during the off peak periods (E10 hours)

That's the conventional off peak arrangement.

So if she wanted the bottom immersion could be wired to the off peak fuse box with no need for your own timer so one less expensive thing to go wrong.

There's only one situation I can think why that might have happened would be one job I did, a loft conversion, and the specification said to include a point for a "boiler" in a cupboard in the loft.  When I came to second fix, the "boiler" turned out to be a dual immersion off peak hot water tank.  I had to use a timer for that one as it was fat too late to pull another cable through.

 

[kerching]

Are the neutral and switched live terminals not behind the two little blank plugs next to the L and N outputs on the meter?

They were on the last one that I did

Just saying

 

[pewe]

When I visited mum at the weekend she presented me with a bill from the electrical contractors (see the attached.)

It is very badly worded and some content ('no looking at the heater') make no sense at all.

The most interesting part of this bill is where they say 'It is believed that the element to the heater is faulty and so a plumber is needed to diagnose and rectify this fault'.

So an electrical contractor (a member of NIC/EIC) is suggesting that they cant diagnose an immersion heater fault, want a plumber to do this and replace the element and then THEY would return and replace the thermostat !!!!!!!!!!!

And to cover the cost of their contractors time for this fiasco they want the customer to pay the bill.

Do I live on another planet - or do they??

 

[Sharpend]

You've just picked the wrong electricians!

 

[pewe]

You've just picked the wrong electricians!

We realise that now, but they are a largish firm in the town, and are recommended by a number of housing associations - or at least they are on their lists - and we have not seen any negative comments about them - until now.

Well you live and learn as they say.

As an addendum, I still have not had a reply to my request (see earlier post) and on querying this lack of response was told 'The Managing Director has been busy and will have a look at your queries at the weekend'.

Well, the weekend has come and gone - so lets see what the next few days brings.

 

[Sharpend]

Sorry to say but these firms that work for housing associations and the like pay peanuts so get monkeys in most cases. Much better at an independent spark as they're reputation is based on each job they do, unlike the larger firms whose reputation is usually based around money.