Is it really that easy to fit a timer to a immersion tank heater?

[home_improver]

Hi I'm new to the forum (although I have been following it as while via twitter).

I've just moved into an old house that has amongst other things, just an immersion tank heater for the hot water (storage heaters in the house).

It's not on a timer so I have to switch it on last thing and remember to switch it off in the morning (economy 7 rates).

I've seen some timers in the local DIY shop - looks like you just break into the cable and wire in / wire out from the back of the timer.

Is it really that easy? What about electrical loading, what am I looking for on the packet e.g "capable of handling xyz current" etc.

I know enough to isolate via the fuse box (which should be fun as the house was previously two flats and none of the fuses are identified as what they are for.

Any help or links to a suitable timer appreciated.

Thanks peeps. - Jonathan

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[cj]

Hi Basically Yes is the answer to your question but the timer must be capable of supporting the full load current of the heater .This is usually 3Kw ,although smaller elements can be found.(check the rating plate look for wattage 3000 or similar.) Most DIY outlets stock an Immersion heater timer but check it is rated to switxh at least 13A at 240v (uk use)and that this rating is for an Inductive load. Some of the cheap imports use inferior relays or contacts which are only rated 5A when used with inductive loads.

Other on group may have recomendations of actual units and pricing .

HTH CJ

[Andrew Gabriel]

Immersion heater isn't an inductive load, so immersion heater timers will not be rated for inductive loads.

It is high current switching, and these units do have a limited life. Buy a good quality one, not a bargin basement one. Make sure the quality of connections you make is good (clean conductors, tight terminals making good connections). Position the unit somewhere where it isn't going to be covered in clothes or other potentially flammable items, so that if it does eventually burn out, there isn't likely to be serious consequential damage too. It might last longer if it's not located in a hot cupboard with the tank.

I bought one about 15 years ago. It has 7 day timeswitch function, and the ability to press a button to get an extra 15 minutes (IIRC) of heating during the day (press multiple times to get multiples of

15 minutes). Make is Kingshield. Don't know if it matches current products. Also had button press to switch between GMT and BST, although you may not want to use that with Economy7.

I actually used it to turn off a large old printer in the office overnight, but if someone was working late, they could fire it up if necessary. So I can't vouch for how well it would handle the full load current, but it ran for several years in the office. It has some sort of capacitor backup to retain programming over power cuts, but it probably can't survive more than 24h without losing the programming (can't recall exactly how long).

[Harry Stottle]

I have had a similar one for over 15 years, a Smiths ETU7000, and never had any problems, this has a built in capacitor backup which has coped with any power cuts during its life. The settings are a bit complex, but versatile, so site it where if can be clearly and easily adjusted if needed, and do the same as I did, tie the operating instructions to the cable just underneath the unit, that way they are always there when you need them, which proved very useful a couple of times. Here is a link to one that looks identical, but the Smiths name has changed to Timeguard, it might be worth checking for lower prices for that model on the web, but I could only find it at CPC

[Woody]

With respect, if you need to make such queries one must question whether you are competent/safe to do the job?

[Martin]

"With respect", there's a first time for everything - and for everyone. The real danger is when someone does NOT ask first.