Solar water heating

[bjay]

Looking to change from gas water heating to solar unit.
Anyone have experience of this.
Rent out the villa over the summer and want to make sure there is plenty of hot water.
Is a back up system needed or is there always enough hot water, I suppose there's a possibility that 6 adults would be taking a shower before a night out
Have been advised that a 300litre tank is big enough, anyone got an opinion on that.

[widge]

You need a back up & 300 litres is ample providing you have one !

I should add that the back up must "kick in" should the solar be insufficient to reheat the hot water that's consumed / used. So if they empty the hot water in the morning & it rains all day the immersion or boiler or whatever must take over the heating duties so they have hot water in the evening.

[alf1956]

How much would a solar water heating set up cost ?

[Sheila]

The one we have just installed has a built in electric backup that automatically tops up when there is insufficient sun.
It was 2700 plus Iva.
Seems to work very well. We turn the electric part off at the mains when it is very sunny.

[Aldo]

who did you use?

[maccasa]

I installed a 320l unit when my villa was built 5-6 yrs ago - works very well and has a built in thermostatically controlled 1.5kw immersion heater, which kicks if water falls below 32-35C. Never had it happen even with 8 people in the villa, except when the sun didn't shine.

Also note there is a mixer valve for summer and winter setting - summer position 5-6, winter 2-3. This lets more cold water into the exiting water at summer setting otherwise its scalding even as it's set for 40C max.

However, last year did notice a slight leak and when I checked the main thermal fluid section had corroded around the seal to the water tank. It turned out the main tank was made of mild steel - brilliant piece of engineering fresh water and mild steel!!! the complete tank and heater assembly were replaced by the builder and supplier as it was under 5yrs old. Guess what the new one is made of stainless steel!

Insuatherm are the most reputable suppliers.

[alf1956]

Hello maccasa
Your system sounds like a good one how much was the total cost including installation please?

[maccasa]

don't know as it was part of the builders supply. I will see if I can get the supplier/installers name etc.

[alf1956]

Thanks maccasa

[mcmuller]

got this one last November to exchange my 20-year-old system, and it's with electric backup:

http://www.leroymerlin.pt/Site/Produtos ... 20156.aspx

[pickwick]

Hi

I am pretty sure you need to heat your hot water to between 60 and 65 degrees to kill Legionella!

Pickwick

[alf1956]

Looks a decent set up mcmuller was it easy to install ?

[mcmuller]

@alf1956: we just added a 3-way-thermostat, as recommended in the shop, connected hot and cold water and the power-supply for the electric backup-up heater. Only thing: the 300l deposit is very heavy and not easy to handle.

[alf1956]

Thank you very much for the info mcmuller

[Sheila]

I installed a 320l unit when my villa was built 5-6 yrs ago - works very well and has a built in thermostatically controlled 1.5kw immersion heater, which kicks if water falls below 32-35C. Never had it happen even with 8 people in the villa, except when the sun didn't shine.

How can you tell when the immersion kicks in?