Immersion timer (again)

Neil_Sedaka

Hi all, just looking for some advice.
We have a standard "on / off" and "bath / sink" switch for the immersion.
DW is always leaving it switched on for days and I was hoping to have this fitted to switch off the supply after a set time.

We don't want a programmed timer that you use to heat the water at specific times, just something simple.
Anyone any experience with this unit? any suggestions welcome.

Thanks.

Stoner

Neil,

I had a look at that switch. It says it can carry 3KW. However most domestic immersions have a 1.5 KW sink and a 2KW bath element, and the batch/sink switches decides which one is "on".
This unit can only be used for one of these elements as it seems to be single pole.

So to use it you'd have to drop out one of the elements. I would not recommend messing with the switching so that you would try to keep the bath/sink switch working. If it was me I'd pick the element you use the most and cable it through this.

hobie

I suspect the device is mounted before the normal bath/sink switch ....
i.e. it simply controls the power to the existing switch ..... the bath/sink switch remains in use to select 1.5/3.0 KW elements ....

Horstmann have a web site with contact info here .....

http://www.horstmann.co.uk/

It's a nice idea .....

Stoner

hehe , nice one Hobie, I never thought of that, that's the simple way of doing it, just break the feed to the immersion switch, but keep the immersion switch

Lex Luthor

was going to say same as hobie and install prior to your current Bath/Sink On/Off switch.

Nice idea alright

311

It's hard to locate insulated switches like these ,I definetly wouldn't order one from ebay.

hobie

_Brian_ wrote:

It's hard to locate insulated switches like these ,I definetly wouldn't order one from ebay.

This link has contact info ...... maybe ask them for Irish Distribution info ...

http://www.horstmann.co.uk/aboutus.asp

hobie

Here's a similar one (1hr and 2hr) .....

http://www.radionics.ie/cgi-bin/bv/rswww/searchBrowseAction.do?obs=sObs&name=SiteStandard&No=0&N=0&Ntk=I18NAll&Ntt=291-5049&Nty=1&D=291-5049&Ntx=mode%20matchpartial&Dx=mode%20matchpartial&callingPage=/jsp/homePage/homePage.jsp&BV_SessionID=@@@@1550081082.1182457622@@@@&BV_EngineID=ccddaddlemmhemmcefeceeldgondhgk.0&cacheID=ieie&Nr=avl:ie

Neil_Sedaka

Thanks for the replies folks.
Yeah, I was thinking it could go "before" the existing switch and simply act as a "power on / power off" kinda thing.

Have an electrician mate that will most likely install it for me, don't like messing with high load stuff like this. Always conscious of the fire risk due to overloading etc.

311

hobie wrote:

Here's a similar one (1hr and 2hr) .....

http://www.radionics.ie/cgi-bin/bv/rswww/searchBrowseAction.do?obs=sObs&name=SiteStandard&No=0&N=0&Ntk=I18NAll&Ntt=291-5049&Nty=1&D=291-5049&Ntx=mode%20matchpartial&Dx=mode%20matchpartial&callingPage=/jsp/homePage/homePage.jsp&BV_SessionID=@@@@1550081082.1182457622@@@@&BV_EngineID=ccddaddlemmhemmcefeceeldgondhgk.0&cacheID=ieie&Nr=avl:ie

Hobie ,it's the ampage that burns out switches.
I was in O'riellys last month and they hadn't got any .

hobie

_Brian_ wrote:

Hobie ,it's the ampage that burns out switches.
I was in O'riellys last month and they hadn't got any .

I'm lost .... are you saying Radionics are selling duff equipment? ....

311

hobie wrote:

I'm lost .... are you saying Radionics are selling duff equipment? ....

Hobie ,that switch is listed under central heating controls /ventilation.

The reason I am been anal about amperage in these switches is because ,a high percentage of house fires start at the hotpress.
I really wouldn't consider buying stuff like this ,without actually consulting someone in a shop or suppliers ,thats all.

Thats not me trolling or being vindictive ,I'd be concerned about stuff like this to be honest.

hobie

_Brian_ wrote:

Hobie ,that switch is listed under central heating controls /ventilation.

The reason I am been anal about amperage in these switches is because ,a high percentage of house fires start at the hotpress.
I really wouldn't consider buying stuff like this ,without actually consulting someone in a shop or suppliers ,thats all.

Thats not me trolling or being vindictive ,I'd be concerned about stuff like this to be honest.

O-key-doke .... looks like NS will have it installed by a competent electrician so let's hope all his "Immersion being left" on problems are a thing of the past ....

311

It's not a lot of help ,but turning down the thermostat on the immersion might help stop energy waste.
At least if it's left on then ,it wont keep eating too much electricity.

cast_iron

I put in one like this just a couple of weeks ago. And as mentioned above, I found the easiest thing was to just out it before the emersion switch. That way, the odd time hot water is needed rather quickly and there's none left, just flick the timer to "on" and change the "sink/bath" to "sink".

Lex Luthor

I bought a 7day/24hr electronic timer from RS a few years back....they have them with the sufficient amperage...just neeed to look harder

Borzoi

Lex Luthor wrote:

I bought a 7day/24hr electronic timer from RS a few years back....they have them with the sufficient amperage...just neeed to look harder

Yeah, Grasslin, Danfoss, all make proper 7 day electronic timers for controlling immersions. Get thm at either an electrical wholesaler on even Woodies/B&Q

hobie

The problem is NS doesn't want a Timer ....

We don't want a programmed timer that you use to heat the water at specific times, just something simple.
Anyone any experience with this unit? any suggestions welcome.

So with that his 'Boost' switch idea seems the way to go .... :rolleyes:

but ........

there is an alternative and it's something an electrician can put in very simply .....

I have a coloured light bulb in our hallway (just outside the hotpress) that lights up whenever the immersion is on ..... it's a 25watt if I rem correctly so uses little power and can be seen for miles!!!! ...... it's bright yellow (you could have a red one if you wish;) ) .....

..... and the cost? ..... about 5 yo yo's plus the leccie's time to connect it ....

The Hill Billy

neil_sedaka:

Why not move the switch to a more obvious area? I don't know if you ever noticed but Grandpa Billy dropped the switch in his house from the hot press down into the kitchen so that it could be seen when the immersion was on when it shouldn't have been. (On the left as you walk into the kitchen from the hall.) Easily done in his house, but may be a tad more difficult in your's.

What if you moved it to the wall on the landing? It would only be slightly more obtrusive than a light switch.

See you later.

MBSnr

Horstmann E15 or E30 from www.heatmerchants.ie

Selected Product:338993

Description HORSTMANN ELECTRISAVER E15 ELECT TIMER
Price (Excluding VAT and quantity discounts) €32.10

The trouble I have is they are supposed to be protected by a Double Pole switch which isolates the timer from the mains. (If you're replacing a combined on/off bath/sink switch then that is double pole - means that both the live and neutral to the immersion element are isolated). Even though the timer itself is DP. Not having a manual DP switch between the immersion and the supply probably is breaking some regulation someplace....

I was also told that as the E15 timer is rated max 13A I should install a DP FCU (fused unit) before the timer instead of just a DP switch even though the unit is on a 20 Amp MCB in the consumer unit.

My simple job just got a bit harder... as really you should have FCU (13A) -> timer -> immersion switch (to get bath/sink option). I plan to use FCU -> timer and not wire the sink in.

I'm sure that doesn't really help things.

Regards

Stoner

The old Horstmann E7 or maybe Horstmann QE7 , they don't look pretty but they never give trouble.
these units don't need a double pole switch, they have one built in, so you don't have to worry about that end of things.

However the listed timer is only rated at 3KW once again 13 Amps.

Also I have never seen or heard of a DP FCU, in my experience it has been a single pole FCU and a double pole switch.

I'll look one up now, but a dual surface box, C/W first , 13Amp FCU, then DP switch, then your timer, followed by an immersion switch sounds a bit mad, IMO

Now I am fairly sure that this could be a simple operation, I might even redeem myself here.

The internal wiring of a HorstmanE7 is carried out buy about 4 or 5 plugs.

It has a boost function giving heat for 1 hour and less,
I think it is possible to arrange the plugs so that only the boost timer suppliers power to the immersion
It will still allow you to choose between sink or bath
and it does not need a double pole switch.

I'll get one in as a sample and bell it out for you if you want, cos it has me thinking.

eoghan.geraghty

This is the common controller used in new apts here with a boost/timer function but like all others I've seen there is no bath/sink option. This is because immersions put into apartments have but one element.
Incidentally the common household immersion has 2 elements, sink 2kw and bath 3kw. Either one or other is on, never both.
You could break the sink feed after the existing switch through this controller, leave the immersion switched permanently to sink ON. Now your controller can be used as a simple boost switch.
But honestly the simplest option is to use the one recommended by cast_iron and you have a day to remember to unset it.


http://www.screwfix.com/app/sfd/cat/pro.jsp?id=44419#

MBSnr

Stoner - You're right it is overkill to a certain degree but I'm just complying with the way I've been advised. I'm putting in a DP FCU with neon before the E15. Then from the timer just wiring the bath and not the sink. Never used the sink element anyhow. If you need a sink of hot water just boil the kettle.....

The DP FCU satisfies the requirement to be able to isolate the supply to the timer and immersion, which I'm told is a regulation(?) and also provides protection to the 13A E15 as my MCB (dedicated circuit) in the CU is 20A and not 16A for some reason.

Neil_Sedaka

Ok, I'm a tad confused now

Would I be ok fitting the Electrisaver E15 before the "bath / sink" switch, or do I need a double pole switch too?

I was planning on leaving the "bath / sink" switch in place, should I maybe remove this alltogether and only use the 3kw feed?

Would I be far better off removing the immersion tank, pipes etc. and converting the hotpress into a rather small, multi screen cinema?

hobie

Leave everything as is ......

ask Horstmann if you can simply have your electrician wire the E15 just before your existing 'on/off/sink/bath switch'

here is the link (half way down the page) .....

http://www.horstmann.co.uk/faqs.asp

They seem to be a good reputable company ....

Horstmann ... we’re in control

As one of the UK’s leading designers and manufacturers of controls for domestic heating systems and advanced metering equipment, Horstmann Controls offers a comprehensive range of state-of-the-art solutions.

Neil_Sedaka

Email sent to Horstmann, will update here with their reply.
Thanks everyone.

MBSnr

Sorry for the long post...

Neil_Sedaka - You should be able to wire the timer before the switch to get timed sink/bath element as hobie as says. That was what I was going to do until I asked on the UK diynot.com forum..... A little learning is a bad thing!

So this is what I found out.

The E15 timer is rated at 13A and the supply will probably be fused at 16A or greater. The reason for me including the FCU (13A fused DP switch) before my timer is twofold.

1. If the immersion element goes faulty it will draw up to the rated MCB in the consumer unit before tripping. If the MCB is 20A (as mine is) then it's possible a faulty immersion element would also blow the timer before the MCB acts. Adding a 13A in the circuit is perhaps "belt and braces" but it should protect the timer from those extra 7 Amps if the immersion element goes.

2. I didn't want the sink element wired (never use it) as I have a oil boiler which does both water/central heating for 6 months of the year (longer if this summer is anything to go by..!). In the times when I need a bit of extra hot water I always use the bath setting anyhow so it suits me to remove the bath/sink switch.

Of course you may need to use both sink/bath.... ;-)

Horstmann are slightly vague in their replies on this timer. I both rang and emailed them. According to them the timer is not DP so you need a means of isolating both poles to the immersion element for repair etc. Your existing on/off/sink/bath switch does that if the timer is added before it, so no problems there.

However their manual says "Means of disconnection from the supply having at least 3mm contact separation in both poles must be incorporated in the fixed wiring".

I queried this because I wasn't sure if they meant "from the immersion to supply" or "from timer to supply" saying I was adding a DP switch before the timer and their reply was;

"The E15 doesn't isolate both Live & Neutral so by fitting a DP switch
ahead of it will fine. Ideally, it needs to have 3mm isolation. (if it's
a proper mains switch it probably has it already be design). We mean in
our leaflet that the 3mm isolation is back at the consumer unit main
ON/OFF switch. In other words - full isolation (3mm clearance) can
always be achieved by switching off the main switch if work is to be
carried out on the immersion heater."

I take from that to mean that as long as there's a DP switch in the wiring (before or after the timer) then things are ok.

Horstmann suggest a 16A MCB to feed the circuit (there are no 13A MCBs). You might want to talk to a qualified electrician/Horstmann about the 13A timer rating if your supply MCB/fuse is greater than 16A (as mine was). I'm not qualified to say whether this is ok without additional fuse protection.

I wired mine up last night with a DP fused switch -> timer running only the bath element.

Like I said a little learning sometimes means more work.....!

hobie

Did I already say this ......

there is an alternative and it's something an electrician can put in very simply .....

I have a coloured light bulb in our hallway (just outside the hotpress) that lights up whenever the immersion is on ..... it's a 25watt if I rem correctly so uses little power and can be seen for miles!!!! ...... it's bright yellow (you could have a red one if you wish ) .....

..... and the cost? ..... about 5 yo yo's plus the leccie's time to connect it ....

MBSnr

It'll have to strobe flash and a have a large klaxon installed for my missus to notice.....

hobie

MBSnr wrote:

It'll have to strobe flash and a have a large klaxon installed for my missus to notice.....

I like that one !!!!! ......

Stoner

hobie wrote:

Leave everything as is ......

ask Horstmann if you can simply have your electrician wire the E15 just before your existing 'on/off/sink/bath switch'

OK I had a look at a Horstman E7.

It requires a 16 Amp MCB.

Its instructions deal with single and twin immersion heaters. For twin elements (sink Bath) you still need the immersion switch to choose between sink or bath. The instructions say that this is to be connected on the fuse side of the immersion switch.

anyway as discussed the boost and the timer part of the E7 can be disconnected inside the box, I have included pics of this. The boost and the timer can be joined so that either or will power the element (or in your case the live into the immersion switch)

So if you dont connect the timer element only the boost will work and it has the 2 hour setting that you were looking for NS.

So with a 16 AMp MCB this unit can have one immersion element hooked up to the enomoy 7 and only the boost will work.

Or as long at the immersion switch has a built in 20 Amp DP as most have you can cable from the E7 to the immersion and the immersion switch will give you the sink bath option