Stat settings Help

BiliousGreen

Hi, I was hoping for some guidance from those that understand the theories if thats possible
I do not have a smart meter so I accept that everything will be a bit of a guess but was hoping there may be some at least theoretica guidance from where to start. 

1) At what point does turning down the flow rate on a combi and leaving the boiler on longer become counter productive? It used to be at 80 and now its at 60? Should I take it down to 50 and have the boiller on even longer??? Or turn it up to 65 and have it go off quicker ( appreciate it maye take a smart meter and trial to figure this out exactly)

2) we tend to have the heating on when needed from a low temp ie 13 degrees or therabouts and turn it off when the stat hits 19. Am I better off at this point leaving the heating on when at home and accepting that teh boiler will fire every 20 mins or so for 20 mins at a  time or letting the house get fully cold and then letting it heat again from scratch for 90 mins orwhatever it takes to hit stat temp from cold. Is this just a case of timing how long the bioler would be on in each scenario or is there more at play. Hope that makes sense - ie boiler on at 1600 and then totally off again at 1800 when 19 deg or so, then back on again at 2100 and off again when temp hit ....... or boiler on at 1600 and just left on all night to keep house at 19deg until bedtime but firing all the time. which is most likely to be the efficient (and cheaest ) one

Many thanks

Alnat1

Set the stat to the lowest temperature you are comfortable with and leave it to do it's work. It will keep topping up the heat as needed.

Better to try 1C lower than turning the system on and off all the time if you want to save a bit of cash.

BUFF

What boiler do you have (most importantly is it a condensing boiler)?
What controls do you have (programmer, room 'stat, TRVs)?

Your building fabric will also influence the answer - every house/heating system will be subtly different - as will user behaviour & tolerance.

BiliousGreen

I have a combi boiler that is 6 years old and a mobile thermostat that sits in the lounge . I think the house is reasonable well inssulated as if we heat it to 19 and then turn boiler off it takes about 3 hours even in this cold to drop to 16 on that stat. At which point we turn the boiler back on and let it heat back to 19 from there rather than just leaving it on. Not sure if this efficient or stupid though
The boiler flow  is set to 60 but its eco setting shows as being around 70 so again not sure whether that matters or whether to ignore that setting

BiliousGreen

anyone have any answers to this? THanks

[Deleted User]

BiliousGreen said:

I have a combi boiler that is 6 years old and a mobile thermostat that sits in the lounge . I think the house is reasonable well inssulated as if we heat it to 19 and then turn boiler off it takes about 3 hours even in this cold to drop to 16 on that stat. At which point we turn the boiler back on and let it heat back to 19 from there rather than just leaving it on. Not sure if this efficient or stupid though
The boiler flow  is set to 60 but its eco setting shows as being around 70 so again not sure whether that matters or whether to ignore that setting

I am tempted to say ‘get a smart meter’. Seriously, as indicated above you are asking an almost impossible question as every home is different. Insulation is different; boiler sizes are different; set temperatures are different etc.

FWiW, we leave our boiler on all day and let the system do its own thing. 

BUFF

BiliousGreen said:

anyone have any answers to this? THanks

well, you haven't fully answered the questions that I asked ...

what make/model is your boiler?
what make/model is your thermostat?
do you have TRVs?

BiliousGreen

I Mini C30 whose eco setting is at 69 degrees
Center thermostat - nothing else marked, it has digital display and a flip front
No TRVs
Thanks

BUFF

This it? https://idealheating.com/uploads/documents/I-Mini-User-Guide-222352-1_users.pdf
Any chance of a photo of the programmer/thermostat?

Does your boiler have weather compensation option installed (probably not I imagine given the Center thermostat)?

Surprising that you have no TRVs on a 6 year old system - they weren't mandatory then (now are) but pretty much everybody knew that  they were a very good idea.

BiliousGreen

Its this one or else it looks identical with same markings / buttons etc 

https://www.amazon.co.uk/CENTER-RF-PROGRAMMABLE-THERMOSTAT-EHE0200361/dp/B0747HYGFK

Yes thats the boiler. 

Sorry misunderstood, we do have TRVs on all the radiators, thought you meant the new smart things I read about. We used to have hot water tank in loft based boiler but it broke so they replaced with combi and got rid of the tank. 

BiliousGreen

Actually I am not sure they are TRVs I think they are just dials from 1-5. They look very old as opposed to the fancy things I see when I google TRV