Immersion Heating V Gas for heating of water

mburke

Hope this is the right thread but does anyone know which is the more efficient way to heat water for a shower / bath between using the immersion or using the gas bolier.

The gas boiler can heat the water without heating the radiators as I have swtiches to turn off the heating of the upstairs or downstairs or both sets of radiators.

Martron

for handyness sake i use the immersion during the summer. leaving the gas alone.

it all comes through the same bill now. efficiency wise i would not know but my boiler is noisy enough so thats why i dont use it

Joey the lips

I have never done the actual unit math but its an interesting question. The way I tend to think of it is

1. Gas is cheaper than electricity So an hour of gas hot water heating is less than an hour of electric

2. The gas heating keeps the coil circulating in the summer which stops a build up of muck around the pump in an old system

But as for the science I dont know. For convience my heating water comes on for an hour 6-7 and from 5-6. That gives me all the hot water I need.

Stratocaster

mburke wrote: »

Hope this is the right thread but does anyone know which is the more efficient way to heat water for a shower / bath between using the immersion or using the gas bolier.

The gas boiler can heat the water without heating the radiators as I have swtiches to turn off the heating of the upstairs or downstairs or both sets of radiators.

The summer switch is there for that reason, If you really want to work out which is cheaper, you will have to sit down and work out how much each is costing.

You can work this out by finding out the KW of your immersion, then looking at the electricity bill see how much each KW is costing you. Work out roughly how long your immersions on for heating the cylinder, do some multiplying and dividing to work out the actual cost of electricity.

With your gas its the same principle, with all your rads off and cylinder cold, turn on your boiler, go outside and check the gas meter, make a note of the reading before and another reading when your happy the cylinders hot, on your gas bill you will see how much you are being charged per m3 of gas consumed. You can then work out how much it costs to heat the cylinder by gas.

I personally find its best to use the boiler but it depends on the installation, if you have long flow and return runs to the cylinder you might experience some heat loss on the way, generally the cost of gas is less than electricity to heat a cylinder, that is why it is now part of the regulations when installing a new heating system to separate the rads from the cylinder.

You should work out when you require the hot water and set the boilers time clock to heat the water in advance with the summer switch enabled over the summer months. This way you wont have the hassle of forgetting to turn on the boiler or immersion etc.

L_gaucho

mburke wrote: »

Hope this is the right thread but does anyone know which is the more efficient way to heat water for a shower / bath between using the immersion or using the gas bolier.

The gas boiler can heat the water without heating the radiators as I have swtiches to turn off the heating of the upstairs or downstairs or both sets of radiators.

Good question. Heres my feelings on it.
I've got, solar hot water, (Kerosene Condensing boiler) , and immersion.
I've a Smart relay controller, with which I can time everything(on times)

I used to use the heating to heat the hot water (Kerosene Condensing boiler) . Its circulates the water into the cylinder coil, and indirectly heats the water. I 've timed this vs immersion to bring the Cylinder to temp (cylinder stat)
Boiler temp runs 70-80 deg. It usually took 2 hrs to take to temp.
Immersion (prob runs well over 100deg I'd guess). usually reached temp in 1 hr under same conditons.

Immersion 3Kw, for 1 hr. 3KWhr x 16c? .. aprrox 50cent/ hr.
Heating Max 3 ltr/hr x 2hrs @ 60cent/litre ... €2.40

I don't believe the heating would be running at full pelt for just water, probably half that €1.20 , still double the immersion.

So, I 've now programmed it to use the immersion only if the heating is not on. (for rads).I reckon if the heating is already on for rads, then its more efficient to use that.

To answer your question, you need to know the KW rating of the immersion, and the consumption of your Gas burner, and try out the calculation..