Electric shower - pull the cord?

SpaceTime

I don't know what the Irish and British are so fixated on electric showers for anyway.
Most other developed countries just have proper water heating systems that actually work efficiently.

This means you have a nice, quiet, high pressure shower with decent rate of flow and even temperature without any need for 45amp circuits in the bathtub!

They're a really strange somewhat 'third world' solution to hot water.

We still have a huge % of homes where hot water is stored in a totally uninsulated copper cylinder or one that's kind of vaguely wrapped in a bit of insulation.

Having lived on the continent and in the US,I just think Irish and British plumbing is usually completely bonkers!

Properly installed hot water should be as or more efficient. You should be using direct gas-fired water heaters that heat the tank and lots and lots of solar heating.

SpaceTime

SpaceTime wrote: »

I don't know what the Irish and British are so fixated on electric showers for anyway.
Most other developed countries just have proper water heating systems that actually work efficiently.

This means you have a nice, quiet, high pressure shower with decent rate of flow and even temperature without any need for 45amp circuits in the bathtub!

They're a really strange somewhat 'third world' solution to hot water.

We still have a huge % of homes where hot water is stored in a totally uninsulated copper cylinder or one that's kind of vaguely wrapped in a bit of insulation.

Having lived on the continent and in the US,I just think Irish and British plumbing is usually completely bonkers!

Properly installed hot water should be as or more efficient. You should be using direct gas-fired water heaters that heat the tank and lots and lots of solar heating.

I think there highly dangerious and am very happy they are rarely found domestically.

Electric showers like other options have there place, irrespective of the country you live in.

jca

gary71 wrote: »

I think there highly dangerious and am very happy they are rarely found domestically.

Electric showers like other options have there place, irrespective of the country you live in.

Do they still use direct gas heaters in Holland. When I lived there years ago it was all I saw. I thought they were brilliant, none of this heating gallons of water in a copper cylinder just to have a shave. Turn on tap, instant hot water, simple.

jca

jca wrote: »

Do they still use direct gas heaters in Holland. When I lived there years ago it was all I saw. I thought they were brilliant, none of this heating gallons of water in a copper cylinder just to have a shave. Turn on tap, instant hot water, simple.

Heaters of this type are called multipoints and work very well if you have a separate home heating source.

The type I assume Spacetime is describing(forgive me if I'm wrong) is stored hot water with a direct fired gas burner below which is inherently dangerious due to being open flued and seeming to usually be situated in the basement.

SpaceTime

Depends on the design.
We had one in France that was balanced flu and completely sealed.

Local small balanced flu instantaneous heaters that work like the water heater on a combie boiler without the radiators part are common too and very very effective.

In another house we'd solar and off peak electric. Huge storage tank that was so well insulated it was basically as good as instantaneous heating and had the advantage of solar.

KoolKid

Moved to Electrical

Sleeper12

Combi boilers are the main thing in the UK. Plumbers in the UK laugh at the idea of a tank in the attic. Having said that they can have mains pressure of up to 10 bar!

Bruthal

jca wrote: »

Surely if the cable is the correct size it should never get hot?

That is correct. Properly sized cable can be loaded indefinitely. It does not just keep heating up.

The time limits on showers is not really to do with electrical, it's to do with allowing the elements to cool down, as the heat dissipation from them is very high while their physical size is very small in showers. They cause heating. I have a kettle that dispenses water into the cup itself, it has a compact 3kw element which heats just 1 cup of water at a time quickly. It also has a duty cycle specified by manufacturer , not because of electrical criteria, but because compact high power elements can't dissipate heat as easily as larger elements. Some gets dissipated into areas outside the heating can. So an off time duty cycle is needed to allow natural cooling. In an immersion, there is a large volume of water to dissipate heat, where as the shower, with 3 times the wattage in the element, it has a tiny heating vessel, so a lot of heat is given off out of the can especially where the element ends come out of it at it's terminals.

Shower isolation switches such as pull chords should not be switched off while the shower is actually running either. I never switch my one off at all. It's a wall switch, which in my opinion are better than pull chords.

SpaceTime

You'll actually also increase the life of your shower if you end the shower by switching the heating function to cold and let cold water flow through it for a few seconds.

It's just enough to give the elements a chance to cool down without having to dissipate heat into the casing of the device itself.

Bruthal

SpaceTime wrote: »

You'll actually also increase the life of your shower if you end the shower by switching the heating function to cold and let cold water flow through it for a few seconds.

It's just enough to give the elements a chance to cool down without having to dissipate heat into the casing of the device itself.

Yes I'd say so as well. Might reduce limescale build up too.

Sleeper12

Bruthal wrote: »

Yes I'd say so as well. Might reduce limescale build up too.

It does help to reduce the limescale build up a little.

corkgsxr

Mira and afaik triton the elements flex slightly and crack off any limescale buildup.

in a high limescale area the head fills up with pieces of half round limescale the element has cracked off

Hoagy

Sleeper12 wrote: »

Bottom line Buy a good quality 50amp switch

Could I ask you what type of 50amp switch you're using?

No Pants

I've got to replace my pullcord switch one of these days. It'll be the second replacement. They don't burn out on me or anything like that, it's just that the pull mechanism gets jammed or something and I don't want to start swinging off the end of the cord in case I break it or damage something.

To summarise; I think I've had a couple of mechanical failures rather than electrical ones.

SpaceTime

Sleeper12 wrote: »

Combi boilers are the main thing in the UK. Plumbers in the UK laugh at the idea of a tank in the attic. Having said that they can have mains pressure of up to 10 bar!

It very much depends on the local mains pressure.

Most houses in the UK still have attic tanks because the mains were deliberately undersized. The idea of the tank was to act as a buffer between the mains and the houses at peak demand.

Aparements in the UK tend to have shared roof tanks though. Irish ones tend to have a weird individual tank in the top of the airing cupboard!?

Sleeper12

I believe one of the most dangerous things happening in the electric shower business is the manufacturers marketing their showers as diy replacement. A lot of diy guys are replacing 8.5kw with 9.5kw showers and they only have 6mm cable. Up until a few months ago the mira elite st was only available in Ireland in 9kw 230v. Most of the original Mira elite showers had 6mm. That's usually borderline right or wrong. Now in their wisdom b&q are selling 10kw 230v showers. How many diy guys will put the 10kw on to replace the 9kw using 6mm cable.

I find it frightening. Some of these may be still on the older 32amp fuse. Pull cord switches will be the least of their worries.
😭

Wearb

Sleeper12 wrote: »

I believe one of the most dangerous things happening in the electric shower business is the manufacturers marketing their showers as diy replacement. A lot of diy guys are replacing 8.5kw with 9.5kw showers and they only have 6mm cable. Up until a few months ago the mira elite st was only available in Ireland in 9kw 230v. Most of the original Mira elite showers had 6mm. That's usually borderline right or wrong. Now in their wisdom b&q are selling 10kw 230v showers. How many diy guys will put the 10kw on to replace the 9kw using 6mm cable.

I find it frightening. Some of these may be still on the older 32amp fuse. Pull cord switches will be the least of their worries.
😭

All the better if they are on a 32A fuse with a properly sized gauge ring. At least it will blow the fuse and then the next one and then they might call a sparks.

lway

Apologies for resurrecting a month old thread but does anyone know a stockist of the Crabtree Pull cord switches in Cork?

My one gave up the ghost after 7 years of service (one of the plastic hooks inside it broke) and I was hoping to replace like with like.

2011

SpaceTime wrote: »

If a cable can heat enough to do insulation damage, it's overloaded and not correctly sized for the task.

Exactly.
Cables should not be sized on the basis that they can sustain the design current for a short time only.

The cable is should be sized correctly for a continious load as should the isolator.
If the isolator is switched on or off under full load conditions it will not last.

Big clunky pull cord switches even when properly sized fail prematurely if they are switched regularly even under no load conditions due to mechanical wear. My advice is to use a double pole wall switch, not a pull cord.
I always leave my shower isolator on. In my opinion it is only there for local isolation when the shower is being maintained.

Wearb wrote: »

I would be VERY disappointed if a 45 amp switch failed when carrying less than 45a, and not even switching under load.

Prepare to be disappointed

lway

lway wrote: »

Apologies for resurrecting a month old thread but does anyone know a stockist of the Crabtree Pull cord switches in Cork?

My one gave up the ghost after 7 years of service (one of the plastic hooks inside it broke) and I was hoping to replace like with like.

Just to answer my own question in case anyone else navigates to here looking for an answer, Dwyers stock the Crabtree 50A Pull switches, cheaper than ebay prices I saw ~€17.