Towel rail bathroom zoning

[PeterB9999]

Hello there,

I wonder if somebody can help advise me. Just in anticipation of people warning me against doing this DIY please be assured I am planning on asking a sparky to come and finally fit the thing, but my question is important to planning my project (though I have now unfortunately bought the stuff!!)

Basically, I'd like to put an electric towel rail above the head end of our bath. The bath is flush to the wall so as I understand it the desired location is Zone 1. Now, I had presumed through my reading that so long as I got an element rated IP44 or above I'd be OK to fit this in Zone 1.

The element I bought is IP44 rated, thermostatic controlled. The instructions given, however, says that "it may be installed in the zone 2 area but the electrical connection box must be outside the zone 2 area". Now, I knew about putting the box on the other side of the wall, but the implication seems I can't use this in Zone 1.

Then, I see that other manufacturers seem to say that Zone 1 is permissible if cautiously installed (whatever that means, as if you'd go out of your way not to install it cautiously in Zone 2)... See here: http://www.geyser.co.uk/-i-23.html

Thoughts and comments would be greatly appreciated,

 

[JohnW2]

The element I bought is IP44 rated, thermostatic controlled. The instructions given, however, says that "it may be installed in the zone 2 area but the electrical connection box must be outside the zone 2 area". Now, I knew about putting the box on the other side of the wall, but the implication seems I can't use this in Zone 1.
Then, I see that other manufacturers seem to say that Zone 1 is permissible if cautiously installed (whatever that means, as if you'd go out of your way not to install it cautiously in Zone 2)... See here: http://www.geyser.co.uk/-i-23.html[/QUOTE]
The situation is a bit messy, since the regulations essentially pass the buck to the manufacturers. 701.55(ix) explicitly allows a towel rail to be installed in Zone 1 (assuming it is at least IPX4, as required by 701.512.2(ii) ), provided that "it is suitable for installation in Zone 1 according to the manufacturer's instructions". It therefore sounds as if (thanks to the manufacturers!) the one you have bought could not be installed in Zone 1, but the other one to which you have linked could be. As you say, the connections/'switchgear' have to be outside of Zones 0, 1 & 2.

Kind Regards, John

 

[PeterB9999]

The element I bought is IP44 rated, thermostatic controlled. The instructions given, however, says that "it may be installed in the zone 2 area but the electrical connection box must be outside the zone 2 area". Now, I knew about putting the box on the other side of the wall, but the implication seems I can't use this in Zone 1.
Then, I see that other manufacturers seem to say that Zone 1 is permissible if cautiously installed (whatever that means, as if you'd go out of your way not to install it cautiously in Zone 2)... See here: http://www.geyser.co.uk/-i-23.html[/QUOTE]
The situation is a bit messy, since the regulations essentially pass the buck to the manufacturers. 701.55(ix) explicitly allows a towel rail to be installed in Zone 1 (assuming it is at least IPX4, as required by 701.512.2(ii) ), provided that "it is suitable for installation in Zone 1 according to the manufacturer's instructions". It therefore sounds as if (thanks to the manufacturers!) the one you have bought could not be installed in Zone 1, but the other one to which you have linked could be. As you say, the connections/'switchgear' have to be outside of Zones 0, 1 & 2.

Kind Regards, John

John,
Thank you ever so much for your very helpful reply. That all makes sense now.
I'll get in touch with the manufacturer, but seems as though I'll be returning this one and ordering one which is specified suitable for Zone 1.
Many thanks once again.
Peter

 

[JohnW2]

John, Thank you ever so much for your very helpful reply. That all makes sense now. I'll get in touch with the manufacturer, but seems as though I'll be returning this one and ordering one which is specified suitable for Zone 1. Many thanks once again.

You're welcome. If you want to keep on the right side of the regulations, you would be advised to try to get a written statement from a manufacturer that their product was suitable for installation in Zone 1, if their published instructions did not say that explicitly. I suspect that they might be unprepared/nervous about doing that - in which case, as you say, you may well end up going with one which is explicitly described as being suitable for Zone 1.

It's really all a bit daft for the regs to 'delegate' the decision to the manufacturers in this way. Provided that it meets at least IPX4, I'm not sure why the manufacturer would have any better idea than the IET as to whether a product was suitable for Zone 1. However, that's how it is!

Kind Regards, John

 

[stillp]

It's really all a bit daft for the regs to 'delegate' the decision to the manufacturers in this way. Provided that it meets at least IPX4, I'm not sure why the manufacturer would have any better idea than the IET as to whether a product was suitable for Zone 1. However, that's how it is!

Kind Regards, John

John, IPX4 means only that the item can resist occasional splashing water. It has no meaning with respect to the ability of the item to withstand prolonged use in a hot and steamy atmosphere. The tests for IP ratings are defined in IEC 60529, and for IPX4 need not be longer than 10 minutes. A cornflakes box would probably pass the test.

 

[JohnW2]

It's really all a bit daft for the regs to 'delegate' the decision to the manufacturers in this way. Provided that it meets at least IPX4, I'm not sure why the manufacturer would have any better idea than the IET as to whether a product was suitable for Zone 1. However, that's how it is!

John, IPX4 means only that the item can resist occasional splashing water. It has no meaning with respect to the ability of the item to withstand prolonged use in a hot and steamy atmosphere. The tests for IP ratings are defined in IEC 60529, and for IPX4 need not be longer than 10 minutes. A cornflakes box would probably pass the test.

I can't disagree with any of that, but the sceptic within me does wonder, in the cases in which manufacturers indicate that installation in Zone 1 is OK, what evidence they actually have that the product is OK for "prolonged use in a hot and steamy atmosphere". There is presumably a limit to how much long-term testing on significant numbers of samples would be considered to be practically/financially viable in relation to a towel rail (of which one manufacturer may have dozens of models to test).

We may also be seeing one of the shortcomings of the Zone definitions. I can well imagine a product which was OK for installation (per OP) at the head of a bath being more of a potential concern within a shower cubicle.

I think the cornflakes box may be a bit of red herring. I agree that it could well withstand a 10-minute 'splashing test' but would fail in service, but that's because the material of which it is made, rather than ingress through any 'nooks and crannies'. I dont think anyone would suggest that the same could be true of the materials used to construct a towel rail. Could you possibly summarise in a sentence or two what the IPX4 test consists of?

Kind Regards, John

 

[stillp]

I can't disagree with any of that, but the sceptic within me does wonder, in the cases in which manufacturers indicate that installation in Zone 1 is OK, what evidence they actually have that the product is OK for "prolonged use in a hot and steamy atmosphere". There is presumably a limit to how much long-term testing on significant numbers of samples would be considered to be practically/financially viable in relation to a towel rail (of which one manufacturer may have dozens of models to test).

We may also be seeing one of the shortcomings of the Zone definitions. I can well imagine a product which was OK for installation (per OP) at the head of a bath being more of a potential concern within a shower cubicle.

I think the cornflakes box may be a bit of red herring. I agree that it could well withstand a 10-minute 'splashing test' but would fail in service, but that's because the material of which it is made, rather than ingress through any 'nooks and crannies'. I dont think anyone would suggest that the same could be true of the materials used to construct a towel rail. Could you possibly summarise in a sentence or two what the IPX4 test consists of?

Kind Regards, John

The manufacturer will know what materials he has used, and will have at least some idea if they are likely to fail when temperature cycling in a humid, steamy atmosphere.
Your comments about the cornflakes box illustrate my point perfectly. What if ingress to the electrical parts was 'prevented' by something like a clay, which would, over a period of time, be permeable, or be washed away?

The test is basically to squirt water at the item under test! IEC 60529 allows the use of either an oscillating tube, bent to a semicircle. with a series of holes, or a spray nozzle from which water is sprayed "from all practicable directions". The product standard is supposed to specify which apparatus is used, and how much water is permitted to ingress, but I don't know what the relevant product standard is. If anyone can tell me what standard deals with towel rails I'll try to get a copy.

 

[JohnW2]

The manufacturer will know what materials he has used, and will have at least some idea if they are likely to fail when temperature cycling in a humid, steamy atmosphere.

Indeed - and one hopes that they would not use materials which were "likely to fail when temperature cycling in a humid, steamy atmosphere" is a product intended for use in bathrooms - of unknown extremes of ambient conditions. I find it hard to believe that a manufacturer who felt their product would be unsafe above a bath or shower tray would be confident that it would be safe 600mm away from that position, where the atmosphere could well be similarly 'humid and steamy'.

Your comments about the cornflakes box illustrate my point perfectly. What if ingress to the electrical parts was 'prevented' by something like a clay, which would, over a period of time, be permeable, or be washed away?

Yes, but that's totally hypothetical. No-one in their right mind would make a product for use in a bathroom out of materials likely to behave in that way. Virtually no metals or plastics would behave in the fashion you hypothesise.

The test is basically to squirt water at the item under test! IEC 60529 allows the use of either an oscillating tube, bent to a semicircle. with a series of holes, or a spray nozzle from which water is sprayed "from all practicable directions".

Thanks. If that test is conducted continuously for 10 minutes, I would have thought that it's likely to be a reasonable indicator of long-term performance - unless/until the product gets damaged or otherwise 'fails'(as above).

Kind Regards, John

 

[stillp]

John, we might have a little misunderstanding. I'm not talking about any particular zone, but I'm suggesting that only the manufacturer can know if his product is OK for use in bathrooms, and that involves knowing more than just the IP rating.

 

[JohnW2]

John, we might have a little misunderstanding. I'm not talking about any particular zone, but I'm suggesting that only the manufacturer can know if his product is OK for use in bathrooms, and that involves knowing more than just the IP rating.

Yes, there is a bit of a misunderstanding. The regs say that a towel rail can be installed in Zone 1, provided that (a) it is at least IPX4 and (b) the manufacturer specifies that the rail is suitable for use in Zone 1. If you look back, you'll see that this discussion (and my comment to which you initially responded) relates to the fact that some manufacturers of such rails indicate that their products are suitable for use in Zone 1, whereas others say only Zone 2 - and I was expressing my doubts as to how/why they came to the respective conclusions.

Kind Regards, John

 

[EFLImpudence]

Apart from all the technical specifications, what good is a towel rail in zone 1 - especially in a shower?

 

[JohnW2]

Apart from all the technical specifications, what good is a towel rail in zone 1 - especially in a shower?

See the OP - this one is above the head of a bath.

Kind Regards, John

 

[EFLImpudence]

Yes, I know but even if it were a wet system radiator with no worries about safety, to me, it seems a daft position.

It is a poor position for heating the room, poor position for towels - in the circulating water vapour and falling off into the bath, poor position for accessing the towels after using the basin etc.

Oh, well - each to their own.

 

[JohnW2]

Yes, I know but even if it were a wet system radiator with no worries about safety, to me, it seems a daft position. It is a poor position for heating the room, poor position for towels - in the circulating water vapour and falling off into the bath, poor position for accessing the towels after using the basin etc. Oh, well - each to their own.

Yes, I agree. I wouldn't personally contemplate it if there were alternatives - but maybe the OP has space/layout issues which limit the options.

Nor is the OP the first person to have thought about the possibility of a towel rail in Zone 1 - since 701.55(ix) specifically relates to this.

Kind Regards, John

 

[securespark]

Here's another thread featuring a towel rail inside a cubicle.

//www.diynot.com/forums/electrics/could-someone-tell-me-whats-not-allowed.338367/#2522259