Hot water timing and indirect cylinder

chaussettesrouges

I’ve recently noticed my hot water cylinder has been using a lot of electricity and wonder if I have the wrong hot water timings.

I have a Megaflo 125l unvented indirect cylinder and a gas boiler. Hot water is timed for 1 hour in the morning, 2 hours at night. Two person household, so 2-3 showers a day plus washing machine and dishwasher 3-4 times a week.

The Megaflo has a ‘backup’ immersion but I am not clear when it kicks in — when the cylinder is empty/cold at any time or only when hot water is on.

I am wondering if I am better of putting the boiler hot water on for longer — supplying more gas-heated water but avoiding using the immersion?

Apodemus

You could try switching the immersion off completely for a couple of days to see if you really need it to be on at all, then adjust your boiler times to match your useage.   Incidentally, its very common for washing machines and dishwashers to be cold-fill (at least in UK), so check to see if yours is actually using your hot water system at all, before working out your boiler times.

jennifernil

Our daughter had a megaflo.  We have a regular vented cylinder.  Both are meant for providing HW heated by your boiler without needing to use the electric immersion heater.


So, if you have a gas boiler, you should be using that to heat your water, as you said, the electric immersion is purely a back up, as in you have it there should there be a problem with your gas boiler.    Otherwise it should be left turned off, there must be an on/off switch for it near the cylinder.

I would not think it "kicks in" automatically at all, you would need to physically turn it on, or have it on a timer.  But basically.....turn it completely off.

Your CH clock where you set times will control only the heating of HW by the gas boiler.

As said already, dishwasher and washing machine will be cold fill, so will use electricity to heat their own water, so the cylinder is heating only the water to the taps and shower, and the times you have set should be plenty for hot water for showers for 2 people, and dish washing of stuff that cannot go in the machine.

ComicGeek

The backup immersion is for when the boiler breaks down - it's only in very unique circumstances that it would be cheaper to use this rather than the boiler.

Make sure the electric immersion is turned off, as that would normally cost 4 times what the gas boiler does. Run the hot water timer on the boiler system as you note above - a 125 litre cylinder is pretty small, so heating twice a day is probably required. Will be well insulated, so any hot water not used will be available for use the next day.

macman

Heating by the immersion rather than via the gas boiler is about 350% more expensive, if on SVT.
Switch it off: for use only if the boiler is out of commission.