16 radiators & I have turned off 7 in unused rooms, will this make the heating bill cheaper?

Question

my husband says NO - he says that the system still thinks it is running 16 rads - who is right, because he's had a big go at me for turning them off?

Answer 1

You are spot on.
Try and explain it to him thus:

The system doesn't know how many radiators it's feeding. It really doesn't give a toss.
What the boiler does is heat enough water to keep X cubic feet of air (the rooms) hot by warming Y square feet of metal (the radiators).

The boiler knows when it has generated enough hot water to do this because the thermostat screwed to your wall (normally in the Hall) tells it to stop heating water.
The boiler has its own thermostat but that should be set higher than the wall 'stat and so doesn't normally activate.

If your wall 'stat is in the hall (normal place) it will keep feeding "heat water" signals to the boiler until the total volume of air in the hall, stairs and landing is at the pre-set temperature. Then it will tell the boiler "stop".
(That's why you shouldn't keep the front door open a second longer than you have to).

The boiler doesn't give a hoot about the unused rooms - provided that you keep their doors closed, of course (otherwise you're increasing the volume of air that has to be warmed).
That is probably where your husband's thinking has stopped.

Now for the flaw in his argument.
The boiler is "sized" to heat 16 radiators. That means it can generate enough hot water to heat them all to max temperature in a reasonable time.
During that "reasonable time" (depends on how cold it is and whether you keep opening doors etc.) it's burning gas at a fixed rate of burn (you can't change that rate - this is improtant). The hot water form the boiler has to heat the metalwork of 16 radiators and the air in their rooms (because the rads in a cool room will take longer to warm up).
This means that to heat the air in the Hall (and operate the Wall 'stat) will take a long(ish) time. Buring gas all the while.

By isolating the unused radiators all the heat energy generated in the boiler (remember the fixed gas burn rate) will be used to heat only the radiators which you want.

Thus they'll warm up quicker and the Hall 'stat will operate sooner and the boiler will shut down faster. Thus saving a considerable ammount of gas. Your "green" credentials go Up and your fuel bill goes Down.
QED.

Even better, fit thermostatic valves to all your radiators, except the one nearest the thermostat. Then you can vary the temperature individually in all rooms. Warmer downstairs and cooler in the bedrooms perhaps. These have long been recognised as good energy saving devices - and they fly in face of your husband's thinking.

Answer 2

Your boiler will use the same amount of energy heating 9 radiators as it would 16, so the bill will be no different. the best way to cut down your bill is to keep the doors to the rooms that you are not using shut this will help. This of course depends on wither you have a room thermostat or thermostat's on the individual radiators. If you have thermostat's on the radiators turn the thermostat down to 1 this will keep the chill out of the room's that you are not using. If you have a room thermostat then you should be able to do the same thing with the rad-valve on one side preferably the one that get hot first when you first turn on your heating. Also you could use a timer that turns on your heating at certan times of the day.
Hope this is of some help to you.

Answer 3

It will take less energy to heat the water,but you would have been better leaving all the radiators on and turning down the thermostat by a couple of degrees. This will keep alll the house warm and stop any pipes from freezing.
I never have my thermostat higher than 14/15 degrees and my house is lovely and warm plus I always keep doors shut and curtains closed throughout the house as soon as it starts to go dusk.

Hope this helps and have a nice day.

Answer 4

I suspect that it will depend on how sophisticated your system is.

I suspect that it will help though; just make sure that for the rooms where the Radiators are you close the doors to those rooms.

If all else fails; do a test. Have the heating done your way for one week and his way for another week. Adjust for any differences in outside tempurature and it'll show you.

If you're REALLY keen, monitor your usage the same time every day for the two weeks. That will help give you an idea.

Answer 5

So you have turned 7 off, meaning the remaining radiators will heat up quicker, meaning you can now turn your heating temp down or limit the amount of time it's on, meaning you will save money, turning radiators off only saves you money if your turn your heating down, so your husband is right to an extent.

Answer 6

The heat from the heated rooms will 'leak' into the unheated rooms which will cause the boiler to be on just as long trying to deliver enough heat from one radiator to heat two rooms, you may save a very small amount, but will have unheated rooms robbing heat from heated areas. Leave the un-used rooms with a lower setting to minimise this effect.

Answer 7

Heating the interior of the external walls makes a big difference, so if the rads turned off are all external wall rooms, your heat losses will be more, in this instance, you will not save much, also depends how well insulated your house is, there are many variables, but just for somebody to say it will definately save money is a nonsense, leave them on, and turn the room thermostat down, this will save more.

Answer 8

Your husband is wrong if you turn the radiators off your boiler will be heating less rooms. But on the down side your house will be colder which will make your boiler work harder which will increase your gas bill.....

Answer 9

This is a hypothetical scenario...........Your house central heating is connected to the neighbours house next door, and you are providing the heat, do you seriously believe that they are getting their heat for no difference to your fuel bill ? It does'nt need you to be a scientist to know that in life , that there is no such thing as a free meal.
Heat is a commodity that has to be paid for.
Some of these answers are pathetic, Why not heat the whole avenue for nothing ?

Answer 10

It will definately be cheaper. I have a system like that at home where i can turn off individual radiators that i dont need to use and it makes a difference to my bills.