Control radiators using thermostat dial?

[blackcloud]

Hello all,

I am having a terrible time trying to figure this out. I am trying to put my radiators in the frost protection mode for 1 week so I am not heating up a flat while away. I called Vokera and one person said you CAN NOT control when the radiators come on using the thermostat. Another one said all you have to do is set the thermostat to a frost protection temperature to 5c. So I did this and tested it by turning the thermostat dial anti clockwise all the way until it reached 5c, it then flashed 5c and went back to showing the current temperature in my flat which is about 20.6. So I thought great, lets see if the radiators turn on now when it hits 7pm and they are due to come on as I have set them to come on at certain times (see pic). Then at 7pm all the radiators came on!!!! Why?? I thought they wouldn't turn on unless the temperature in the flat dropped to below 5c?
Anyhow the guy at vokera who, when I explained this said I must have been pressing something I shouldnt have been pressing and thats why the radiators came on???

I am confused?

I know I can just turn all the radiators down to the frost protection mode on each individual radiator but really wanted to know how to control them with the thermostat.

The other guy at Volerka who said the thermostat doesn't control the radiators, well how can that be as they come on at the times I have set them to on the thermostat? Or does he mean that I can control when they come on but I cant override it on the thermostat to turn them all off unless I make all the hours BLANK on the timer on the thermostat?

(PS the picture of the black dial on the front of the boiler apparently is to control when the boiler comes on and nothing to do with the radiators or the thermostat)

Please can someone help? thanks.

 

[Harry Bloomfield]

Most boilers these days, include frost protection built in - if the temperature of the boiler gets too low, they turn on - the on and off times of your system, should not prevent that.

In addition, somewhere in a particularly exposed location where there is pipework, you might have a separate frost stat, again independent of the on/off times.

 

[blackcloud]

Thanks but my question is in relation to the radiators, why are they coming on when I set the thermostat to 5c?

 

[Harry Bloomfield]

Thanks but my question is in relation to the radiators, why are they coming on when I set the thermostat to 5c?

As I said above, your boiler is sensing colder temperatures and lighting up to protect itself. Part of the process will get the radiators slightly warm.

Or are you suggesting your whole heating system, radiators are becoming hot?

 

[MNW67]

I think you are slightly misunderstanding how the heating works. You cannot directly turn the radiators on and off with the thermostat. The thermostat can only turn the boiler on and off. The boiler then heats up the radiators. That is probably what the Vokera guy was saying.

It is confusing, because you also have the black dial timeclock on the boiler, which can also turn the boiler on and off. So you have two controllers which can do the same thing. But it looks like the timeclock on the boiler is set permanently on, presumably so it doesn't interfere with the thermostat.

Where is the boiler? Is it in a very cold place?

 

[blackcloud]

Thanks, yes the boiler is at bottom of hallway in a very cold place.
I've discovered that basically when I turn the thermostat down to 5c the radiators come on randomly every hour or two for like 5 mins then stop. When I turn thermostat up to 21c the radiators come on exactly the times I've set them to on the boiler and up to 21c.
But I don't want to be heating my flat up via the radiators for a whole week while I'm not hear during the winter so what do I do to ensure the radiators don't turn on or atleast only to the frost bite protection level on the radiators?

 

[MNW67]

I think what might be happening is what @Harry Bloomfield said. The boiler itself is getting so cold, that it fires up for a few minutes to protect itself. And that is why the radiators come on. That is separate from the 5C you have set on the thermostat.

What is the lowest temperature that the flat is getting down to on the thermostat display?

What would you like to happen whilst you are away? Would you like the heating to keep the flat, at say 10C? or lower?

When are you going away?

 

[Harry Bloomfield]

I think what might be happening is what @Harry Bloomfield said. The boiler itself is getting so cold, that it fires up for a few minutes to protect itself. And that is why the radiators come on. That is separate from the 5C you have set on the thermostat.

My boiler is also firing, when it is otherwise off - not every hour, because it's on a sheltered side of the house - but definitely firing long enough to get a bit of warmth into it's system.

 

[ericmark]

Most thermostats have a * which is frost protection,

with the electronic type, you can normally set the eco setting however 5 degrees is a bit on the low side, more likely 12 degrees, to set the wall thermostat, you need to remove the programming, in the main boilers have a separate frost stat,

In this example the FS and FR should go to a frost stat, so you turn the heating completely off, and the frost stat over rides it. Some thermostats do have a button

but most you need to manually change the program. Some do have an off option

but need to read the instructions for yours.

 

[Madrab]

Do you have the manufacturers instruction for your programmable thermostat (stat)? That will show you how it needs to be set when you're away.

7 day RF programmable room thermostat|Vokera

www.vokera.co.uk

If I remember that thermostat doesn't have a 'holiday setting' as such, the frost setting just means that if the programmer is set to OFF then if the temp where the stat is drops down to the set frost setting (default 5 deg), the boiler and system will be run until the stat reaches that temp. If it's still running on AUTO - programmed mode (clock symbol) , the system will just run at the normal desired times and temps.

The stat only reacts to the temp of the room its in so if the boiler itself could be colder and detects that it's below it's own desired frost setting temp but the stat isn't then yes it will run for a minute or 2 regardless off any programmer setting to warm itself up.

 

[stem]

Hello all,

I did this and tested it by turning the thermostat dial anti clockwise all the way until it reached 5c, it then flashed 5c and went back to showing the current temperature in my flat which is about 20.6. So I thought great, lets see if the radiators turn on now when it hits 7pm and they are due to come on as I have set them to come on at certain times (see pic). Then at 7pm all the radiators came on!!!! Why??

It appears to me that you have a programmable thermostat (i.e. one that allows different temperatures to be set at different times)

If so, as @Madrab yours may be set to have a program change at 7pm, and reverted to the programmed setting for that time. Unfortunately I've never used a Vokera thermostat like yours, so can't advise you how to use it. Perhaps the link provided to the Vokera instructions earlier may help you.

Also, if it is a programmable thermostat, the boiler timeswitch should be set to be permanently 'on' 24/7 and looking at the tappets that doesn't seem to be the case with yours.

The room thermostat should be used as the sole controller, otherwise the boiler timeswitch will interfere with the operation of the room thermostat.

 

[blackcloud]

Will be away for a week from Sunday. So wanting to get this sorted by then.
Don't want the radiators coming on every couple of hours or whatever they come on at when I set the sat to 5c.
The boiler is next to an outside wall at bottom of hallway but don't think it gets to as low as 5c.
The sat room temerature shows like 20c when the radiators power up as that is the temperature of the living room where the sat is in.
What shall I do to stop rads coming on while I'm away for a week?
Here's the manual attached.

 

[Mottie]

Just set the heating on constant (not timed) and set your thermostat to say, 10 degrees.

 

[blackcloud]

Really the timeswitch on the boiler should be permanently on?
I just want to stop the rads firing up every couple of hours while I'm away for a week and turning the sat down to 5c does turns the rads off it doesn't stop them firing up every couple of hours or so.

 

[blackcloud]

Just set the heating on constant (not timed) and set your thermostat to say, 10 degrees.

But won't the rads still heat up every so oftern like they do when it's timed to be off but still fire up and then off again.