why switch from gas to electric water heater?

Cardew

Could it be a safety issue?

There have been issues abroad with gas water heaters - particularly old models, causing the death of occupants.

That said a carbon monoxide detector would suffice.

Richie-from-the-Boro

lilac_dawn wrote: »

It took an hour to heat enough for a longish shower this morning - but didn't last long after that.
Would still like to know if there's any way of finding out running costs other than taking meter readings.

Borrow an 'owl' meter from a fiend, use it a couple of times [1hr] [3hrs] etc and record the kWh used and the price per kWh you pay. You will find in 3 hours for example [tank size 100-210-550 litres?] you use 90% of the cost in the first 45 minutes, and so little afterwards that recording the cost [to a 60°C temp - legionella] after 45 minutes is not worth the effort. You will get a totally different kWh consumption and cost reading in the winter than you did in the summer. A summer rising main temp of 15°C is possibly only 5°C in the winter, heating from this low level will require much more energy - ditto as has been mentioned the quality of the insulation, which should at least meet PartL standards. A single element [bottom] immersion is never a good idea. You should really have a two element set up, its pointless heating the top element's 20 litres for a bath, and equally pointless and uneconomic heating 210 litres with the bottom element to do the washing up when you only need 10 or so litres.

Borrow a clamp on electricity monitor.

lilac_dawn

Thanks for the info - I looked into OWL meters a while back and think I can't use one as we're on the 3rd floor and the electricity meter is in the basement. Will look again and see if there is an alternative. Still can't figure out the best way to use the thing so it remains switched off.

Richie-from-the-Boro

lilac_dawn wrote: »

Thanks for the info - I looked into OWL meters a while back and think I can't use one as we're on the 3rd floor and the electricity meter is in the basement. Will look again and see if there is an alternative. Still can't figure out the best way to use the thing so it remains switched off.

- yes you can - put the clamp directly on the electric cable supplying the immersion heater in your dwelling

espresso

Richie-from-the-Boro wrote: »

- yes you can - put the clamp directly on the electric cable supplying the immersion heater in your dwelling

Oh no you can't!

It won't work if you "put the clamp directly on the electric cable supplying the immersion heater in your dwelling".

Richie-from-the-Boro

espresso wrote: »

Oh no you can't!

It won't work if you "put the clamp directly on the electric cable supplying the immersion heater in your dwelling".

- why, it will read current flow, any current flow
- the meter is agnostic .. .. it doesn't care
- meters flow on, stat kicks in, flow off
- clamp the live cable [isolated] only
- its no different to a 'tail'

adamstewart5989

Gas water heaters are dangerous as cmompared to electric water heaters because an inflammable gas in a compressed container is always dangerous. Also the gas heaters have higher cost than electric heaters but the consumption of gas costs certainly lesser than electricity consumption. But there are ways by which you can control the electricity consumption like prepay meters and smart electric appliance.

matelodave

Put your own information into thecalculations below (eg tank size, immersion heater power consumption, temperature rise and cost per unit of electricity) and you can work out how much it costs and how long it will take





Heating water calculations



1 kilogram calorie = heat required toraise 1 litre of water by 1 deg C.

1 kWHr = 860 kilogram calorie.

kWHr = Litres x Temperature Rise deg C / 860 x Efficiency.

kW = Litres x Temp. Rise deg C / 860 x Efficiency x Time in Hours.

Litres per Hr = kW x 860 x Efficiency / Temp. Rise deg C.

Time in Hours = Litres x Temp Rise deg C / 860 x Efficiency x kW.

Therefore time in hours = 2 x 80 / 860 x Efficiency x 0.6



Example


To heat a 150litre hot water tank from15 to 85 degrees = 150x(85-15 = 70)/860 = 12.21kw/h assuming 100% efficiency(which is mainly what an immersion heater is) although there will be somelosses due to heat dissipation from the tank, depending on the amount o finsulation

So a 3kw immersion would take about 4hours to fully heat a 150 litre tank from cold, whereas a 1kw heater would take12 hours. In both cases it still takes 12kw which would cost 12x15p = £1.80


Also, unless you are heating the tank from cold every time the temperature rise required would be less so you’d use fewer kw/h and it would take less time. Likewise it depends where the immersionis located in the tank – right at the bottom and it will try and heat all 150 litres, halfway up then it would only be about 75 litres

Dunroamin

lilac_dawn wrote: »

It took an hour to heat enough for a longish shower this morning - but didn't last long after that.
Would still like to know if there's any way of finding out running costs other than taking meter readings.

If you can't turn it on and off, how do you know this?

matelodave

Richie-from-the-Boro wrote: »

- why, it will read current flow, any current flow
- the meter is agnostic .. .. it doesn't care
- meters flow on, stat kicks in, flow off
- clamp the live cable [isolated] only
- its no different to a 'tail'

It will only work if you clamp it round the live wire, not just the cable going to the immersion heater otherwise the current going up the live is countered by that going down the neutral and the net result is zero. When its clamped onto the electricity meter tail it only goes on the live one, not both live & neutral.

So the only way is to strip off the outer insulation (being everso careful that you don't nick the insulation on the three conductors) and tease out the live to put the clamp on.