[Chris Nation]

Sorry to ask such a banal question but I haven’t seen anything elsewhere that helps – and my architect has not answered the query, either – yet

I am starting from scratch in the renovation of my small 2-bedder in Valencia, VLC. There is mains gas and lekky. The most efficient and economical way to provide hot water for a shower is a cold-feed electric shower. Are these a common fit in Spain?

From what I have seen – and it is the case with my present setup – a small tank, heated by lekky at socket-outlet amps, feeds the shower. When the tankful of hot water has been used up, there’s a wait till the refilled tank comes back up to temp.

This is not satisfactory if I rent the place AirBnB-style, to two couples. And not a good solution, in any event. Even with a thermostat and insulation, the heating element must cycle to maintain the tank of water at temperature, whether used or not.

The other solution would be to have water heated by a gas boiler, run into a holding tank and then through a pump to give sufficient pressure, which there very rarely is, direct from a gas boiler. This would be a lot more expensive to buy, fit and run and not as effective/effivient as a cold-feed electric shower.

I’d be very grateful to hear from anyone with experience of making this sort of decision.

[Mark Stücklin]

Hi Chris,

An electric shower sounds like the way to go in your case. They are easy to find in Spain. You can even order one from Amazon (search ducha eléctrica)

[Chris Nation]

Mark. Thanks very much. Strange how it was not easy to dig that info out of any other source.

Here comes my supplementary, as per P.M’s Qs
– I have been signed up to Iberdrola on a 5.5KW deal. My guesstimate is that an 8.5KW cold feed shower should be adequate for Spanish conditions at the coldest time of the year in VLC city, though as with any other system demanding power, you can never have too much.
– The key is the capability of the shower to raise the water from ambient to +/- 40°C, which is a ‘hot’ shower
– These electric showers draw a lot of amps for a short time. How does this square with any particular standing charge power rating? If one has an 8.5KW shower, does that mean the power rating from the electricity company must exceed that? Or is 5.5KW the monthly ‘allowance’? Electric ovens are common: they draw 4-5KW.
– I’d be very grateful if you could explain what you get for a 5.5KW deal, bearing in mind these high-draw gizmos.

[Chris Nation]

I hope youcan decipher that reply. It seems to have included formatting stuff.

[Miles]

Hi Chris,

I live in the Canary Islands which may be a bit different from Valencia, but most holiday rental properties here have a boiler for hot water, with a cold water feed direct from the mains or an aljibe (outdoor water reservoir). You can buy various sizes of boiler, and the smaller one should give you enough hot water for two 5 minute showers before it runs cold. Bigger ones are usually for larger properties with more bathrooms, showers, etc., and of course take up more space and cost a bit more to run as there is more water to keep hot.

Hope this helps. Check out your local Ferreteria (DIY shop) as well, they usually offer good advice.

[Chris Nation]

Miles, thanks for your reply.

Here I paste a part of my original query, to which Mark replied with what I had hoped would be the answer.

From what I have seen – and it is the case with my present setup – a small tank, heated by lekky at socket-outlet amps, feeds the shower. When the tankful of hot water has been used up, there’s a wait till the refilled tank comes back up to temp.

This is not satisfactory if I rent the place AirBnB-style, to two couples. And not a good solution, in any event. Even with a thermostat and insulation, the heating element must cycle to maintain the tank of water at temperature, whether used or not.

So the trad Spanish way with hot water supply is exactly what I aim to avoid. With a cold feed shower, any number of people can shower one after another – or shall we say ‘back to back’ ! – and as soon as the last one hits the ‘off’ switch, no more power is being used.

The question I now need to resolve is how the rating capacity that one has with the lekky company squares with high-draw appliances such as showers, ovens, a/c and the like. Does one have to have an account which provides a KW capacity that exceeds the possible maximum current draw at any one time? For example, someone might be using the shower on the ‘high’ setting, drawing 8.5 KW, whilst a 2KW room heater is running, along with constant-draw items such as fridge, freezer and others. If one has a 5.5KW account, does that scenario result in the main trip flipping?

[luzcadiz]

If as with most apartment blocks the roof is flat are you not able to apply to your communidad to install a solar hot water system?

We have this on the costa de la luz coupled to an immersion heater [very rarely needed] but are going solar but still on the grid next year.    A tank on the roof even with insulated piping going down an outside back wall would also give you a good head of water and a  more powerful shower.   Initial cost may be more but greater client satisfaction and less reliance on ever increasing electric bills should make it worthwhile.   If you are thinking of short term rentals  [and Valencia will probably go that route] it might be worth checking the requirements listed in the tourism permits already issued for say Barcelona and more recently Andalucia which includes air con for summer rental and heat for winter rentals.   Not only that but you will need to provide a complaints book, declare all your taxes, issue invoices and more paperwork etc . . . so all has to be 100% perfect.

 

[Chris Nation]

Luzcadiz, thank you for your comment.

For 7 years I owned a boatyard on the Tamar in Devon. ‘Docamenti’ is a familiar matter to me. VAT, Nat Ins, PAYE, ‘elf and Safety …. I had a bloke from the Min of Ag and Fish turn up one day to inspect my ‘Animals Prohibited To Come Ashore’ sign [“A bit rusty…..”]. Queen’s Harbour Master Devonport paid me £10 p.a for a speed limit sign on a post by my slipway. Though I could believe that a modest 2-bed short-let flat in Spain involves more bureaucracy than the boatyard.

Your suggestion of  solar water heater is a good one. If the communidad would allow the installation, the pipe could run down the lightwell straight into either the bathroom or kitchen and then T off to the other. As I’m effectively 3 storeys below the roof, the pressure would be enough to blast barnacles off a hull.

But note my confession in my reply to Poppy. How do these tariffs work?

[Poppy]

We have a gas combi boiler that heats water instantly (and radiators) so never run out of hot water and no need for a space consuming water tank. Quite expensive to buy and install though.

[Chris Nation]

Poppy, thanks for your comment. Do you run a shower from the combi boiler?

Combi boilers often fail to produce enough flow/pressure to give a decent shower. It depends on the KW output of the boiler. This is my experience in UK but this may well be on account of the proportion of hot water to cold required is much higher in UK because of the low ambient temp of the mains water coming into the house.

The heat exchangers in gas combi boilers are not designed to give high temps AND high flow, as electric cold-feed showers are. Good for basins and baths but I’ve seen some pretty wimp showers running off combi hot water delivery. You have to add a pump to the system.

So, in my UK house I had a combi boiler for radiators and the bath/sink/basin h.w. and a lekky shower over the bath. This was a prefect set-up for UK and is very common.

But my ignorance remains total, in so far as I still don’t understand what a 5.5KW tariff means. If you have a 4.5KW lekky oven on, plus the devices that may well be also running on a continuous basis [in practical terms] like fridge and freezer and you turn on a 2KW room heater or a washing machine, does the main trip flip?

Do you, as you have to with working out the AmpHrs of 12 volt battery capacity in a boat/camper, have to total up all the devices which might conceivably be running at any one time, and go for a tariff next up from the result total of the calcs?

[Chris Nation]

Poppy, your comment about a gas combi boiler has become more interesting since I had a conversation with a very experienced UK electrician who has cast his professional eye over many different set-ups over the years he has been on holidays in Spain.

He reckons that if there is enough pressure to feed a cold-feed electric shower, there is enough to feed a shower heated by a gas combi

Do you run a shower off your combi?

[Speakfreak]

Bit late but just to say I have a mains pressure cold feed gas fired boiler. Unlimited amounts of fantastic showers being had here in Barcelona! No tanks, and far cheaper than electricity. Those Instant electric showers need special wiring to the fusebox and any decent one will be over 10Kw.

[Chris Nation]

Thanks Speakfreak. That is the way I’d prefer to go. It all depends on mains pressure. Clearly, you have enough.

[Poppy]

Sorry for late response. Our  gas combi heated shower has the best pressure in the house!

[JohnLloyd]

Hi if you are on a 5.25kW tarif then your electricity consumption at any time is limited to a Max of roughly 5.25 kW hence an 8kW shower alone will probably trip your house breaker but together with say an electric kettle will trip it for sure. Just put an instant heat gas boiler in its cheap to run and will give hot water for as long as the water is run and the gas bottle is not empty. In the UK a house has say an 80 amp supply and as each 1kW equates to 4amps at 250v then using even a 12kW shower is fine. 12kW = 48amps. This is not the UK and your house has very small electrical capacity. Either supply or actual wiring. Solution in your situation clearly a gas water heater. Hope that helps.

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