Help me understand my hot water system!

Pincher

When I was in a hot country, in 28 degrees, I rushed to the shower every opportunity I got. Maybe you work in a fish restaurant. Whatever the reason, the hot water should be arranged around YOUR life, not the other way round.

Learn to use your timer for the gas boiler.

The BOOST button is the best thing since roast beef served at the table on a trolley.

If you don't have a timer, get one WITH a BOOST button.

pops66

Robin9 wrote: »

A bath a week - whether you need it or not !

Or take the advice of Elizabeth I - bath once a year whether you need it or not.

Apparently women used to bath once a year in the Spring, which is why they carried posies of scented flowers at weddings.

Badger2015

Sorry to high jack the thread but I wonder if someone can help me. I run private gym lessons in a cabin in my garden and have to pay for heating the hot water. Sometimes I have one client a day sometimes one a week and sometimes non a week depending on my commitments as I am a mum. In the summer I may have 4 clients a day. The hot water is only used for clients to take a shower. I am the sole user. The gym has a prostel direct 120l cold fill unvented hot water cylinder heated electrically. Is it cheaper for me to leave on all the time or only put on the boost function when I know a client is coming. It is possible to set a timer too so that could be an option although as I said there are days and weeks when I won't use it at all. I'm not sure what would be the most economical way to run it. Also on the boost function how long would I need to leave it on for the water to heat?

matelodave

If we can calculate the volume of water and the required temperaure rise, we can answer this question.

The following formula is used to calculate the power of heating element needed to heat a specific volume of water by a given temperature rise in 1 hour.
volume in litres x 4 x temperature rise in degrees centigrade / 3412
(4 being a factor and 3412 being a given constant)

for example 120 litres of water, to be heated from 10ºC to 60ºC, giving a temperature rise of 50ºC would give – 120 x 4 x 50 / 3412 = 7kwh

Meaning that the water would be heated in 1 hour by 7kwh of applied heat.
so it would take around two and a half hours if you've only got a 3kw immersion heater

If you pay for you leccy at peak rates (around 14p kwh) it would cost you 7 x 14p = 98pence to heat the tank.

Obviously if you decided that you didn't need the water so hot you could save some time & money by turning the stat down and in the summer the incoming water wouldn't be as cold so it would take less time and thus less power to heat the water.

Only you can decide when you need hot water but it will cost you more to keep it hot all the time. Ideally you'd need to limit the flow volume and time that people stand in the shower.

A standard shower can supply 15-20 litres a minute x 10 minutes = 150-200 litres which could easily empty your tank. Whereas a flow restricted shower at 7lpm and limiting showers to 5 mins = 35ltres = 3-4 showers out of a tank full. (it's not quite that as you'd be mixing cold water with the hot - but you get the idea)

Alternatively an electric shower which only heats the water when it's being used might be a better option.