Hot water boiler on all time or just when needed?

The hot water heats up so quickly that we switch it on as & when needed. Having said that we have gone out for the day and left it on by mistake. The tank is thermostatically controlled so I hope it hasn't gobbled up too much gas It works like an immersion tank holding a limited amount of hot water - as you'll discover if you stay in the shower for too long!

In summer we leave it switched on when we are in the caravan but swutch off when out for the day. In winter as we leave the heating on the  water heater stays on too.

What type of water/space heating do you have? It is not on demand like a combi boiler at home (even if its called a combi - this refers to water and space heating all in one). Ours is thermostatically controlled so it won't be heating (water or space) all the time only when it falls below a certain temperature. If you're on EHU, you can keep the van and water heated quite hot on the 1Kw setting.

we switch it on when we get onto a site & switch it off when we leave x days later

i think either is fine...the thermostat will stop the unit overheating but, if you are out for the day and its heating and cooling (insulation not as good as at home) then it will be using fuel (gas or leccy) to maintain this heat.

you could also just heat on demand, say early in the morning for a shower, turn on for 20 mins to give a full tank of hot water.

for washing up, we generally boil a kettle as it will take a while to run the hot through from the tank to the tap, wasting quite a bit of water considering you just want a bit to wash up in.

so, if you're paying for fuel (gas or metered leccy) i would just turn on when needed for a shower.

similarly, if having to fetch water, why waste it by running it down the sink waiting for the water to run hot? try a kettle instead?

good luck.

We always leave ours on all the time. Boilers are more fuel efficient and, therefore, cheaper to run if left on. Leaving it on only allows the temperature of the water to drop slightly before the thermostat kicks in and the heating element turns on for a short time. Turning it off allows the water to cool considerably and then the element has to work far longer to bring the water up to temperature.

We always leave ours on all the time. Boilers are more fuel efficient and, therefore, cheaper to run if left on. Leaving it on only allows the temperature of the water to drop slightly before the thermostat kicks in and the heating element turns on for a short time. Turning it off allows the water to cool considerably and then the element has to work far longer to bring the water up to temperature.

good post, I'll think I'll leave it switched on too from now on.

We always leave ours on all the time. Boilers are more fuel efficient and, therefore, cheaper to run if left on. Leaving it on only allows the temperature of the water to drop slightly before the thermostat kicks in and the heating element turns on for a short time. Turning it off allows the water to cool considerably and then the element has to work far longer to bring the water up to temperature.

good post, I'll think I'll leave it switched on too from now on.

Thanks. We leave our gas boiler on all the time at home for the same reason and have differering temperature settings throughout the day. The boiler doesn't fire up a lot but it would burn for ages to heat the house from cold.

but once you've had your showers (two in our case) the hot tank will be cold.

so, if it were left on permanently, then each day, the water has to be heated fully from cold (and maintained at that temperature) even though you arent necessarily going to use it.

if the next time you need hot water from the tap is the following morning (we wash up using a kettle) its more efficient to heat it once the next day (morning) than have it heat/cool/heat all day when its not needed.

however, if you wash up from the hot tap, or must have hot water in the washroom sink, then you might as well keep the water boiler on as TW says.

the thing is, as the water in the hot pipe cools quickly after use, it then takes a while for hot water to make the trip from boiler to tap, so when washing hands or doing washing up, much cold water is wasted while waiting for the hot to come through, hence our use of a kettle to wash up, only using whats required.

im happy to wash hands in cold(ish) water.....rather that than watch litres run unnecessarily down the waste...

But if you use the superb site facilities for showering it saves using your own hot water and filling/emptying tanks so often.

Our hot water is instant so we dont waste water by running off cold and have no need to boil a kettle for dishes, or to wash our hands in luke warm water. 

but once you've had your showers (two in our case) the hot tank will be cold.

so, if it were left on permanently, then each day, the water has to be heated fully from cold (and maintained at that temperature) even though you arent necessarily going to use it.

if the next time you need hot water from the tap is the following morning (we wash up using a kettle) its more efficient to heat it once the next day (morning) than have it heat/cool/heat all day when its not needed.

however, if you wash up from the hot tap, or must have hot water in the washroom sink, then you might as well keep the water boiler on as TW says.

the thing is, as the water in the hot pipe cools quickly after use, it then takes a while for hot water to make the trip from boiler to tap, so when washing hands or doing washing up, much cold water is wasted while waiting for the hot to come through, hence our use of a kettle to wash up, only using whats required.

im happy to wash hands in cold(ish) water.....rather that than watch litres run unnecessarily down the waste...

here endeth the first lesson