Taking hours to heat the house

theoretica

If it takes ages to heat up, how rapidly does it cool down?  Sometimes just shifting the timing of your heating earlier works so it comes on well before you get up/come in, but turns off sooner too.

ariarnia

theoretica said:

If it takes ages to heat up, how rapidly does it cool down?  Sometimes just shifting the timing of your heating earlier works so it comes on well before you get up/come in, but turns off sooner too.

that is part of the 'efficiency' side of things.

if we heat only the lounge using the stove then it heats up really quickly. but if the rest of the house is unheated then we need to keep it going a lot longer because it also loses a lot more heat. with our current set up of the hole house at 15 and fire in the lounge we can light the fire at about 5 and let it go out about 8 or 9 (so only about 3 or 4 hours of logs and about 20 kwh of gas). and the house/lounge are still warm the next morning so we don't need to wake first thing to a cold house and immediately light the fire. the bones of the house hold on to more heat. 

i think it was @FreeBear who was saying heat loss is about relative temp. so a hot room with cold rooms next door and thin internal walls loses a lot more heat (so needs more energy to keep warm) than a hot room with warm rooms next door. 

so your not comparing how quickly you can heat that one room with the electric heater. you also need to think about how long you are running that heater for to keep that one room warm enough compared to how long the central heating would be running for to keep that one room warm enough and the rest of the house 'not cold' using thermostatic valves. 

Chrysalis

theoretica said:

If it takes ages to heat up, how rapidly does it cool down?  Sometimes just shifting the timing of your heating earlier works so it comes on well before you get up/come in, but turns off sooner too.

CH cools down slower but not enough of a difference to make it worthwhile.

Last time I used CH the feeling warm lasted maybe 20 minutes after was turned off, whilst portable heater its gone quicker.  But the speed of the portable heater to provide heat easily overcomes that.

To get CH heat to last a while after turning off, insulation issues need fixing.

The choice could be 4 hours of gas for 30 mins heat, or 35 mins of electric for 30 mins heat.  This one probably drives the point home better.

I think there just needs to be a recognition here that CH isnt a one size fits all solution for everyone, too many think what works for them must apply to everyone else.  

Now of course if I had different circumstances, children in their rooms needing to keep warm at same time, then the metrics change.  As CH would be better than running portable heaters in multiple rooms at once. (I would probably move as well though to somewhere with double glazing if I had children, wouldnt want to bring up children in this property with the condition of windows)

ariarnia

Chrysalis said:

theoretica said:

If it takes ages to heat up, how rapidly does it cool down?  Sometimes just shifting the timing of your heating earlier works so it comes on well before you get up/come in, but turns off sooner too.

To get CH heat to last a while after turning off, insulation issues need fixing.

The choice could be 4 hours of gas for 30 mins heat, or 35 mins of electric for 30 mins heat.  This one probably drives the point home better.

I think there just needs to be a recognition here that CH isnt a one size fits all solution for everyone, too many think what works for them must apply to everyone else.  

i agree not one size fits all. but the bit that's missing from that is the 30 mins of heat costs the same as maybe 2 hours of gas (depending on boiler size heater size how hard its working and exact unit prices). 

so in most houses theres only a small window where the electric heater might work out cheaper (because the gas will come to temp and do less and less to maintain the temp when the electric heater is still having to chug along). 

thats why i use an oil filled rad in my office (because i try not to be stuck sat at my desk as much as possible). if i have to be in there for more than an hour or 2 then the cheapest option is to turn up the rad in that room. 

which is why the op really needs to figure out if the problem is heat escaping to quickly (so how. would sealing gaps and door curtains make a difference) or the heat not getting into the room in the first place (rads turned to low at the valve or full of air). or if the boiler is set on a go slow (flow temp to low). 

Chrysalis

I might have some answers as to the what the costs would be for the gas heating.

So using smart meter data, I had water heating on for about 2 hours on Friday, sarahs mode says it is 15.6 KwH (central heating would be at least that, my boiler if I have CH on I have to also still heat water). 

15.6 (11.9) x 10.24p = £1.21

2000 watt heater on for 2 hours, and we will assume worst case scenario its on constantly not thermostat controlled.

4 x 33.02p = £1.32

maths look ok to you?

Thats best case gas against worst case electric.

--edit recalculated taking of normal pilot light daily usage.

Depressing figures, just 2 hours of heating per day over £30 extra per month on bill, the problem is if you start at 1-2 hours, it makes the unheated hours so much more difficult as body adjusts to the heated temperatures, so 2 hours quickly becomes 8 hours.  Reality is though the electric heater would be lower then that cost as thermostat would cycle the power.

My last 2 bills were pretty much covered by the Gov payments, due to cheaper dailies, I expect to be back up to about £85-90 month in December though, now I did these maths I am tempted to buy a heater and do around 4 hours of heating a day which would be covered by the £67.

Therese1

Hi all, thanks for the tips and ideas.  I bled all of the radiators yesterday…from the bottom to the closest to the boiler.  The last one (the one you can’t regulate temp of) was full of air, the others all seemed to be fine.  

Anyway, I switched the heating back on to see if this helped and it was still showing 15° and no more even after a few hours.  

HOWEVER! When I went upstairs to go to bed, every window up there (two bedrooms and bathroom) looked like I had been running a sauna!! Not just a bit of steam/condensation at the bottom….the whole of all of the windows!!  Neither bedroom rad was on higher than 1 (of 5).  

This suggests that the house is in fact heating….right??    Trouble is, with the Nest, because the heating is never getting to the requested temp 18°, it’s on constantly…..first time EVER my heating has been on for 9 hours …three times this week😵‍💫  

any other clues before I call out a plumber….or should it be a Nest specialist?? 

Lorian

double glazing? that's moisture in the air condensing on the cold surface. Monitor and potentially reduce the humidity in the house. Always use your extractor fans in bathrooms and kitchen. Try and keep the house to less than 60% humidity. Keep the bedroom doors shut during the day. Keep all the curtains/blinds shut before it goes dark and always when cooking/showering. Humidity monitors from about £7 on Amazon honestly pretty much every house should have one, very topical.

As for the slow heating what is the flow temperature on your boiler set to -  potentially it's too low and this is only the first bite of winter.

chris_n

Therese1 said:

Hi all, thanks for the tips and ideas.  I bled all of the radiators yesterday…from the bottom to the closest to the boiler.  The last one (the one you can’t regulate temp of) was full of air, the others all seemed to be fine.  

Anyway, I switched the heating back on to see if this helped and it was still showing 15° and no more even after a few hours.  

HOWEVER! When I went upstairs to go to bed, every window up there (two bedrooms and bathroom) looked like I had been running a sauna!! Not just a bit of steam/condensation at the bottom….the whole of all of the windows!!  Neither bedroom rad was on higher than 1 (of 5).  

This suggests that the house is in fact heating….right??    Trouble is, with the Nest, because the heating is never getting to the requested temp 18°, it’s on constantly…..first time EVER my heating has been on for 9 hours …three times this week😵‍💫  

any other clues before I call out a plumber….or should it be a Nest specialist?? 

It is highly unlikely to be the Nest it is just a clever switch. You can check it with a thermometer. How much gas are you using in an hour?

Therese1

The radiator temp on my boiler is 61° …is this too low? 

Water is at 47°

Therese1

Yes, double glazing and I always have window open when shower is on and kitchen extraction fan when cooking.  This was extreme steaming of windows last night and only upstairs….last I remember it like that was a cold NYE party pre Covid when the house was full of folk! 🤣  only me now!!