am I using my boiler / thermostat wrongly?

coconutcurls

In my last flat the thermostat was digital and could be programmed 

In this flat the thermostat is very basic - a dial with numbers from 0 to 6 

I usually turn the thermostat up or down and the ‘radiator’ dial (there is a radiator picture) on the boiler up or down respectively 

Sometimes I turn the thermostat down but forget to turn the boiler down…am I wasting gas / paying for gas when this happens? Even though the heating is turned off?

Reed_Richards

The radiator dial on the boiler will control the set temperature of the water leaving the boiler.  The lower the temperature of the water leaving the boiler then the less heat the radiators will give out but the better the efficiency of the boiler (assuming it is a condensing boiler).  I would set the boiler to as low a setting as keeps you warm and use the thermostat to change the temperature of your flat. 

coconutcurls

@Reed_Richards thanks


my boiler has two dials - one with a radiator picture and one with a tap picture

I use the one with the tap picture to regulate the temperature of the water from taps

So the dial with the radiator picture is to control the water inside radiators right? If my thermostat is on the lowest setting zero but boilet radiator dial is high, even though the housing is not being heated, am I wasting gas / paying for gas?

BUFF

If the house is not being heated you shouldn't be (unless it is an old boiler with a permanent pilot)

Reed_Richards

coconutcurls said:

So the dial with the radiator picture is to control the water inside radiators right? If my thermostat is on the lowest setting zero but boiler radiator dial is high, even though the housing is not being heated, am I wasting gas / paying for gas?

Yes, you correctly understand what the symbols on the two dials mean.  If the flat thermostat is on the lowest setting then that probably just gives your flat "frost protection" by keeping the temperature a bit above freezing.  So the gas boiler will be off and not using any gas unless you are away for days in cold weather.  You need to keep your flat above freezing to prevent pipes being frozen and damaged so any small gas usage required to achieve that is not wasted.

If you just turn the thermostat down when you go out and/or at night then you won't be using any gas during that time.   

markin

The boiler setting is for efficiency of the system, only minor changes should be made on it, Say 56c if outside temp is +5c Or bumped up to 65c if its -5c and its taking hrs to heat the house up to temp.

The room thermostat is how you control the actual home temps you want.

Norman_Castle

coconutcurls said:

@Reed_Richards thanks


my boiler has two dials - one with a radiator picture and one with a tap picture

I use the one with the tap picture to regulate the temperature of the water from taps

So the dial with the radiator picture is to control the water inside radiators right? If my thermostat is on the lowest setting zero but boilet radiator dial is high, even though the housing is not being heated, am I wasting gas / paying for gas?

No, set it to 60 and leave it there. If your boiler is using gas you will hear it working.

Reed_Richards

Have a look at Figure 2 in this scientific paper, it is often cited elsewhere:
https://www.sciencedirect.com/science/article/pii/S019689041730016X
What it says is that the lower the return water temperature, the more efficiently a condensing boiler will run.  In effect this means there is no "right" temperature setting for the boiler output water, the lower you can make it the more efficiently your boiler will run.  But the lower the set temperature, the longer it will take for your radiators to warm up your house and if it is set too low then your house won't get to the temperature you want it to be in cold weather.  You'll just have to experiment to find out what works for you.

Setting the boiler output temperature lower as the weather outside gets warmer is called "Weather Compensation".  Some boilers will do this automatically.  Leaving the output water temperature higher whilst you are warming up your flat then turning it down when it gets to near the temperature you want is called "Load Compensation".  Again, some boilers will do this automatically. You could do either or both manually if you can be bothered, and it should save you a bit of money.  But for simplicity, find the lowest setting that works for you in cold weather and leave it at that.

It's quite possible that you could replace your existing thermostat with one that lets you program times and temperatures.  Often these devices fit onto a standard backplate in which case very little effort is needed to replace one type with another.  The cost of such a programmer is anything upwards of about £60.