Gas on constantly or on and off...?

Jon_Tiffany

Cardew wrote: »

You are really referring to condensing boilers here, and this myth has been around long before those were invented.

No, this applies to all boilers regardless of type. The lower the temp of the water returning from the rads the more efficient the boiler. Heat travels from hot to cold, the bigger the difference the faster (more efficient) the transfer.

Its the same for your house, the hotter you have it the faster you lose heat to the outside.

The effect is more noticable in a condensing boiler, because over a certain temp (around 55 degrees) the boiler stops condensing. A non-condensing boiler will also work as a condensing boiler while the return temps are low - but the acidic condensate will soon corrode the boiler.

Its also worth noting that turning off radiators reduces the overall efficiency of a heating system.

Important - efficiency and the cheapest way to run your heating may not be the same thing! Eg. - Efficiently heating your house while you are away on holiday for two weeks is not the cheapest way to run your heating.

closed

inaminute23 wrote: »

There's my point if you put it on longer you use more gas.

Exactly!...

inaminute23

closed wrote: »

Exactly!...

Longer on the timer from a cold start! Totally different.

closed

If you put 2 cups of water outside now, one at 20 degrees C, and one at 10 degrees C, which loses heat faster?

inaminute23

closed wrote: »

If you put 2 cups of water outside now, one at 20 degrees C, and one at 10 degrees C, which loses heat faster?

You have just set yourself up for a big fall!

Yes, you are correct the warmer one does. Hot water freezes quicker than cold because the sudden shock in temp, but my living room is inside my house not outside, how silly! Plus i don't lose much heat because it tops up during the day. The fact is since i got in at 6.45pm with my heating on all day the desired temp (19) has not dropped at all, and the boiler was last burning gas at 7pm!!!

Oh dear expalin that?

inaminute23

closed wrote: »

If you put 2 cups of water outside now, one at 20 degrees C, and one at 10 degrees C, which loses heat faster?

That doesn't work vice versa neither. Meaning warmer water will boil quicker than cold. Hence 24/7 stat controlled heating is cheaper for me.

HappyMJ

inaminute23 wrote: »

Laws of physics - you can't simmer a standard household kettle all day with out topping it up. Also these are mainly electric, and we are talking gas. However if you insulated your kettle it would boil quicker.

Why electric? The one I was assuming that Cardew was talking about was a kettle on a gas stove which is the cheapest way to boil a kettle and the gas can be turned down so it just simmers away quietly. My mother used to do that on a cold day. She'd fill up a kettle boil it up then turn it down to simmer have a cup of coffee sit down watch telly and then just go back and fill up for another mug without having to wait for it to boil and the heat would also have the added bonus of keeping the kitchen warm thereby in her eyes saving money on the heating bill.

inaminute23

Jut over 4 hours since my boiler last fired, and my heating has now dropped 1 degree.

closed

The posts are getting bizarre now, your boiler hasn't fired up for 5 hours apparently, and your room temp hasn't changed, but after midnight, you maintain that if the boiler was switched off with a timer, the house temp would plummet.

Hot water doesn't freeze quicker than cold, it loses energy quicker.

You don't lose much heat because it tops up during the day, where do you think that topup comes from?

House/Cup of water, same principle. The fact that you do topup, means you lose more heat.

Biggles

davecon1 wrote: »

This discussion seems endless

That's the only thing that's certain. It's not only endless, but it starts up again at this time every year, with people comparing their (totally different) houses with other people's and insisting their usage and experience proves that they are right (whatever it is they are trying to prove!).

Completely pointless.