Thermostat setting

AbiAl

Hi all,

This is my first post so please bear with me. I recently had a smart meter installed and I realise how inefficient we have been with energy use. We are now okay with electricity but I need help with an energy efficient setting for gas this winter.

I have a Vaillant Ecotec 832 set at 50 flow for water and 55 for radiators. I have a Salus TR105F portable thermostat which I have meddled with for years and always been cold. I now realise switching it off and letting the temp drop really low is inefficient. It is currently off all the time set to day 16 and night 21. I have found that it means it switches on the boiler if the temp in the house goes below 16 and off when it hits 21. The thermostat is a room that has the most moderate heat, not too hot or cold. At the moment school is out and everyone is home and I wonder if that is how I should set it and what to do when everyone returns in January.

I am also concerned if temp drops to 16 late in the night it kicks in and starts working towards 21. We have some heat escaping which is being addressed but what I need help with really is the thermostat setting. What is ideal when everyone is home all day and when we return to the daily grind. All advice gratefully received.

Merry Christmas

Astria

I normally have the thermostat on 14 during the day/night and 17 during the evening.

But if it's 17 all day, the difference is typically about 50p/day - it'll obviously use less gas during the day, but a lot of gas to go from 14 - 17, so the difference is very slight.

NannaH

My Vaillant ecotech is 60° flow temp and my smart thermostat is set between 17.5 and 18.5 in the day/evening and usually 14 at night and never normally comes on,  I set at 16 the last 3 nights and it’s been coming on  around 03.00, minus 8/9° where we are.
I’ve used around 62 kwh a day for the last 3 days (£6.85 incl. standing charge)  so I’m going to change the overnight to 14 and see if it’s markedly different.  

From the 3-10 Dec,  it was roughly 44kwh/day so under a fiver.  

My Daughter has her thermostat set to 15° from 08.00 to 15.00,  while everyone is out during weekdays and 17/18 in the early mornings + evenings so it will be interesting to compare her useage with ours.  When I’ve picked up my Grandson from nursery and taken him home,  the temperature has just been approaching 15° and only takes maybe 20 mins to get back up. 

InvertedVee

AbiAl said:

Hi all,

This is my first post so please bear with me. I recently had a smart meter installed and I realise how inefficient we have been with energy use. We are now okay with electricity but I need help with an energy efficient setting for gas this winter.

I have a Vaillant Ecotec 832 set at 50 flow for water and 55 for radiators. I have a Salus TR105F portable thermostat which I have meddled with for years and always been cold. I now realise switching it off and letting the temp drop really low is inefficient. It is currently off all the time set to day 16 and night 21. I have found that it means it switches on the boiler if the temp in the house goes below 16 and off when it hits 21. The thermostat is a room that has the most moderate heat, not too hot or cold. At the moment school is out and everyone is home and I wonder if that is how I should set it and what to do when everyone returns in January.

I am also concerned if temp drops to 16 late in the night it kicks in and starts working towards 21. We have some heat escaping which is being addressed but what I need help with really is the thermostat setting. What is ideal when everyone is home all day and when we return to the daily grind. All advice gratefully received.

Merry Christmas

Welcome the forum and thank you for your first post!

If you've read other threads you'll see that there are huge differences between homes and between peoples' desired temperatures.

You're absolutely correct in thinking that leaving the central heating on all the time does not mean that the boiler burns gas all the time. You've chosen to have a set temperature of 21C, a setback temperature of 16C and you're managing with a relatively low flow temperature of 55C. That's all very reasonable.

For me, at home all day, it works better to have a smaller difference between the set and setback temperatures. I use 19C from 0600 to 2300 and 17.5C overnight and I can use a flow temperature as low as  48C. That may not work for you, depending on all kinds of factors to do with your home and heating system.

You mention that your home will soon be unoccupied during the day. That may give you the chance to make some modest savings by using a daytime setback but they may not be as big as you think. If you changed your one daily 'warm period' of say 16 hours to two periods totalling 8 hours, you wouldn't be halving your consumption of gas. The system would need to push more heat into the cooler house to get the temperature back up again. And the intensive heating may need a higher flow temperature, which is less efficient.

So what to do? Well, if you were out of the house within an hour of waking up and back home a couple of hours before bedtime, it would make no sense keeping the house relatively warm all day. But if it's just about finding an arrangement for school hours, I'd suggest using your Salus thermostat/programmer to put in a setback a couple of degrees less than your normal daytime setting on school days. Something like this...

• 0600 20C
• 0800 17C
• 1500 20C
• 2300 17C

The longer the house is unoccupied, the lower you could make the setback temperature for the period in the middle of the day. But be careful not to go so low that you end up needing a much higher flow temperature to get things up to cosiness in the afternoons. It's complicated!

Hope you will be able to find a pattern that works for you.

AbiAl

Thank you all for taking out of your valuable time to respond. If I am honest we are quite comfy at 17 so whilst the weather is so cold I think I will make the lowest 16 and highest 19. I don't know how to set the thermostat to have a specific temp for specific times. I will look into it. I used quite a lot of energy to push it up to double digits and we are now looking to maintain it.

Once I figure out how to have specific temps for specific times, would something like the below be reasonable?

0600 19C

0800 16C

1500 19C

2300 16C

If the day temp is still 19 and night is 16, what happens between 8 and 3. Will the thermostat keep triggering the boiler. I have looked for videos on my thermostat but can't find anything in English.

macman

The programmer doesn't set the temp for a specific time, but for a period. You programme in the on/off times, and then you can set a temp for each period. So, if i understand your post correctly, the temps you posted are the target temps for each starting time. so, at 3pm the stat will start to increase the temp from 16C to 19C. It will maintain it at 19C until 11pm and then allow it to drop back to 16C again. If you have the timer set to 'off' for any periods, then that overides the 'stat: so the boiler will not fire at all, regardless of the ambient temp.

JGB1955

You might want to consider setting your overnight temperature at 14C or 15C.  If you're tucked up in bed you'll not notice the difference.

Astria

AbiAl said:

Thank you all for taking out of your valuable time to respond. If I am honest we are quite comfy at 17 so whilst the weather is so cold I think I will make the lowest 16 and highest 19. I don't know how to set the thermostat to have a specific temp for specific times. I will look into it. I used quite a lot of energy to push it up to double digits and we are now looking to maintain it.

Once I figure out how to have specific temps for specific times, would something like the below be reasonable?

0600 19C

0800 16C

1500 19C

2300 16C

If the day temp is still 19 and night is 16, what happens between 8 and 3. Will the thermostat keep triggering the boiler. I have looked for videos on my thermostat but can't find anything in English.

If the temperature in the room is higher than the setting then nothing will happen, simple as.

So if the temperature drops from 19 to 16 from 6am till 3pm then the thermostat won't request heat and the boiler won't come on.

Why not record the usage with the above and then try again with it on 18c all day? The difference might surprise you.

Oh and don't forget that on Monday the temperature is forecast to be 13c! Quite a big jump. Might not need any heating

AbiAl

You have all been incredibly helpful. You have no idea how much I appreciate it. I guess I did not understand how the thermostat maintains temp. Needless to say I am going to give it a good go. My usage has been horrendous the past two days whilst I push the temp up.JGB1955 said:

You might want to consider setting your overnight temperature at 14C or 15C.  If you're tucked up in bed you'll not notice the difference.

Worried if I let it go that low it will require a high flame to rise again

JGB1955

AbiAl said:

You have all been incredibly helpful. You have no idea how much I appreciate it. I guess I did not understand how the thermostat maintains temp. Needless to say I am going to give it a good go. My usage has been horrendous the past two days whilst I push the temp up.JGB1955 said:

You might want to consider setting your overnight temperature at 14C or 15C.  If you're tucked up in bed you'll not notice the difference.

Worried if I let it go that low it will require a high flame to rise again

Yes, but that will have been counteracted by being off for the previous 8/10? hours.  Last night was particularly cold and the heating kicked in at 04:00 - not full belt, just a bit of a tick-over.  Looking at the weather forecast for the next week, I expect it to kick in at (maybe) 05:00 tomorrow, then not again until it's normal 07:00 for the next week or so.

Edit - apparently the temperature is going to change from -2C to +1C overnight, so I anticipate the heating NOT disturbing me at all until 07:00 tomorrow.

AbiAl

Hi all,


So everyone is home at the moment and will be virtually everyday until the new year. I have my boiler flow temp at 55. The attached is my thermostat. I set my day to 19 and night to 17.  Then the period is 10am to 10pm and the night is 10pm to 10am. Does this look right?

We don't get in until about 6 when schools resume so I am thinking day period of 5pm to midnight then night from midnight to 5pm.

Are these efficient settings? Thanks again.