New Boiler - Weather Compensator?

[Alucidnation]

It depends on the model as to why sensor fits.

I dont think you can strap any old sensor on to them.

[Jerdan13]

Weather compensators,should only be an added control to your heating system,the principle of a WC is an early warning system of temperature change outside,

due to u values in new dwellings it may take time before the indoor thermostat reacts to external rise or fall in temperature,this is where the WC comes into play,its an additional control to energy savings,

but to be honest ,most are fitted incorrectly,e.g the hot water system over rides your WC ,the hot water and your central heating are in essence 2 different systems fed mostly by same heating device

the hot water system has nothing to do with the temperature of your dwelling or building,its use is for bathing and tap usage,your central heating is for heating ones home or premises

but it has come to my attention that most WC systems are set up to be over ridden once hot water calls for temperature rise via thermostat etc,it seems it turns the WC off or over rides it,this should not be the case,as it is a different zone or system

[Jerdan13]

Also weather compensators work best with ground source driven heat pumps,weather compensators restrict massive temperature blasts in radiators etc,this is something people will have to adjust to,fitting a WC may save you as much as 15% on your heating energy,if you are one that likes piping hot radiators ,don't fit a WC as they are designed to give a more balanced heat flow,and react to external Temperature rise or fall.

due to new building regulations (technical guidance document Part L) it may be no longer possible or viable to meet renewable energy requirements per metre square of your dwelling ,using traditional boilers and solar panels.

The new heating method will be Heat pumps , due to their superior efficiencies

[Alucidnation]

Christ forgot all about this thread.

Anyhoo, as an update, the WC system has been working fantastically and has reduced our gas bills by quite a bit.

Would recommend.

[Jerdan13]

Despite what people think,weather compensators are not designed to make your boiler or other heating devices ,to work harder,the principle behind them is to make your device work less ,and stop your heating source from cycling

This leads to lower but more stable temperature to your rads or underfloor heating,most boilers are oversized in dwellings so cycling boilers or over heating water costs more

same principle goes for your hot water,why turn your hot water upto 90 degrees ,only to cool it down again to wash your hands or bath in,you waste all this energy to get water near to boiling point ,before cooling it down again

yes you should turn your hot water thermostat over 60 degrees every month or so to kill off any likely hood of legionnaires or other harmful bacteria

[Jerdan13]

Also it is good idea to leave your heating on 24/7 ,if you are leaving building unoccupied for any length of time,leaving system on 24/7 is the way your heating system is supposed to work ,with out manual intervention,e.g your system is time and temperature controlled,or should be

so you time clock,for argument sake,turns boiler off during night or time inputted,even tho thermostat is saying temperature is dropping,like wise when timer allows system to come back on for say a period of 3 hours,the thermostat may turn system off after an hour if required thermostat temperature is reached,this is known as time and temperature control,

So if one is leaving a dwelling unoccupied for a length of time ,especially in colder wet weather,i would suggest setting thermostat to around 15 or 16 degrees,to stop damp cold weather from compromises the fabric of said dwelling materials,as this may lead to costly refurbishment costs if dwelling is left unheated over a period of time ,due to mould growth etc

[eliot]

Alucidnation said:

Christ forgot all about this thread.

Anyhoo, as an update, the WC system has been working fantastically and has reduced our gas bills by quite a bit.

Would recommend.

Ok then, how many sq ft is your house and what is your gas bill for nov,dec,jan,feb?
And is your house occupied during the day?

Edited by eliot on Sunday 10th March 19:01

[Alucidnation]

eliot said:

Alucidnation said:

Christ forgot all about this thread.

Anyhoo, as an update, the WC system has been working fantastically and has reduced our gas bills by quite a bit.

Would recommend.

Ok then, how many sq ft is your house and what is your gas bill for nov,dec,jan,feb?
And is your house occupied during the day?

Edited by eliot on Sunday 10th March 19:01

Why?

Is it that your are going to try and tell me it’s too expensive, house is too big, inefficient insulation Etc etc

[eliot]

Alucidnation said:

eliot said:

Alucidnation said:

Christ forgot all about this thread.

Anyhoo, as an update, the WC system has been working fantastically and has reduced our gas bills by quite a bit.

Would recommend.

Ok then, how many sq ft is your house and what is your gas bill for nov,dec,jan,feb?
And is your house occupied during the day?

Edited by eliot on Sunday 10th March 19:01

Why?

Is it that your are going to try and tell me it’s too expensive, house is too big, inefficient insulation Etc etc

Because you state it’s working well and has reduced gas bills - but with no evidence.
I dont run wc, instead i run the boiler very hot and have a reasonably wide hysteris on the thermostats (to avoid cycling). My gas bills are lower than average for the size of the house (according to my supplier- but of course could be nonsense)
I know someone running the wc on the same boiler as me in a house that’s been tested as airtight with mhvr and the boiler just seems to run all the time and has high gas bills - BUT he has an 8k sq-ft house so not easy to compare for various reasons.

I’m litle under 3k, new house, work from home - so it’s on during the day.
Feb £56 (2144Kw)
Jan £78 (3022Kw)
Dec £61 (2367Kw)
Nov £50 (1932Kw)
Feom the summer leading up to Nov it’s from £11 to £25 which is just hot water and £8 standing charge. For the size and the fact i’m at home quite a lots - I don’t think that’s too bad - but have no comparison.

Edited by eliot on Monday 11th March 07:37

[FiF]

Out of interest wouldn't it be better to compare kWh rather than cost as we're all on different deals.

Not sure even then it's valid comparison, go back to family up North and the prevailing weather is "an extra layer" colder.

[eliot]

FiF said:

Out of interest wouldn't it be better to compare kWh rather than cost as we're all on different deals.

Not sure even then it's valid comparison, go back to family up North and the prevailing weather is "an extra layer" colder.

I’ve added the Kw to my post.
But, yes it’s difficult to compare - as it also depends on how hot you heat your water and the house. Generally I heat to 20-21 when occupied and off overnight.

[springfan62]

eliot said:

Because you state it’s working well and has reduced gas bills - but with no evidence.
I dont run wc, instead i run the boiler very hot and have a reasonably wide hysteris on the thermostats (to avoid cycling). My gas bills are lower than average for the size of the house (according to my supplier- but of course could be nonsense)
I know someone running the wc on the same boiler as me in a house that’s been tested as airtight with mhvr and the boiler just seems to run all the time and has high gas bills - BUT he has an 8k sq-ft house so not easy to compare for various reasons.

I’m litle under 3k, new house, work from home - so it’s on during the day.
Feb £56 (2144Kw)
Jan £78 (3022Kw)
Dec £61 (2367Kw)
Nov £50 (1932Kw)
Feom the summer leading up to Nov it’s from £11 to £25 which is just hot water and £8 standing charge. For the size and the fact i’m at home quite a lots - I don’t think that’s too bad - but have no comparison.

Edited by eliot on Monday 11th March 07:37

If you run the boiler hot you're not going to be getting the boiler into condensation mode, the lower the return water temperature the better to ensure the heat in the flue gases are condensed and then available to use. Otherwise the heat goes out the flue with the steam. So its very unlikely you are using the boiler efficiently. Also setting the boiler temp high and then having a high hysterisis will lead to relative loss of comfort as the room temperature is not maintained at a constant level.

The figures for energy use give mean nothing unless they are compared to a similar house operated with different settings.

[FiF]

eliot said:

FiF said:

Out of interest wouldn't it be better to compare kWh rather than cost as we're all on different deals.

Not sure even then it's valid comparison, go back to family up North and the prevailing weather is "an extra layer" colder.

I’ve added the Kw to my post.
But, yes it’s difficult to compare - as it also depends on how hot you heat your water and the house. Generally I heat to 20-21 when occupied and off overnight.

Thanks, not sure how many sq FT we are, will check out of interest later. But our gas bills are higher than yours I'd say, no WC, 4 beds, 2.5bath, but not a big house in size if you get the drift. 18-19c, generally off at night, 24-7 heating in v cold weather esp if wind has any northerly in it. Insulation not up to modern new build levels.

[eliot]

springfan62 said:

If you run the boiler hot you're not going to be getting the boiler into condensation mode, the lower the return water temperature the better to ensure the heat in the flue gases are condensed and then available to use.

Yep well aware of condensing mode - i'm not that convinced that the benefit of low water temps to achieve it outweigh the benefit of ignoring it and running it hotter for better heat transfer. I think it's probably more relevant with underfloor heating, where you dont need high temperatures and you tend to run them much longer where condensing mode helps.

Mines a system boiler, one circuit does the house and dhw via zone valves. Having the boiler temperature low enough to achieve a low enough return temp for condensing for the rads meant it ran for a very long time trying to heat the DHW to even high 50's.
Having it flat out, means it heats the DHW quickly (30 mins for a 250L tank from about 35'c) - I guess, if it's like an intercooler on a car; you get the best transfer when the temperature delta between the boiler loop and the dhw is high. Also rads tend to be sized according to a high water temperature too - although i did over size those to an extent anyway.

[springfan62]

eliot said:

Also rads tend to be sized according to a high water temperature too - although i did over size those to an extent anyway.

If you size your rads with a delta T of 50 it will happily run at a low temperature and 50 is the standard for domestic boilers now.

You may not be convinced that operating in condensing mode but it will save 10-20% of energy costs on a well designed system, it sounds as though perhaps your's wasn't correctly sized for the thermal properties of the house.

[herewego]

eliot said:

springfan62 said:

If you run the boiler hot you're not going to be getting the boiler into condensation mode, the lower the return water temperature the better to ensure the heat in the flue gases are condensed and then available to use.

Yep well aware of condensing mode - i'm not that convinced that the benefit of low water temps to achieve it outweigh the benefit of ignoring it and running it hotter for better heat transfer. I think it's probably more relevant with underfloor heating, where you dont need high temperatures and you tend to run them much longer where condensing mode helps.

Mines a system boiler, one circuit does the house and dhw via zone valves. Having the boiler temperature low enough to achieve a low enough return temp for condensing for the rads meant it ran for a very long time trying to heat the DHW to even high 50's.
Having it flat out, means it heats the DHW quickly (30 mins for a 250L tank from about 35'c) - I guess, if it's like an intercooler on a car; you get the best transfer when the temperature delta between the boiler loop and the dhw is high. Also rads tend to be sized according to a high water temperature too - although i did over size those to an extent anyway.

I've seen that average new build heating consumption is expected to be a ludicrously high 5 to 6000 kWh. You've used 50% more than that in just 4 months although yours is larger than average.

[herewego]

springfan62 said:

eliot said:

Also rads tend to be sized according to a high water temperature too - although i did over size those to an extent anyway.

If you size your rads with a delta T of 50 it will happily run at a low temperature and 50 is the standard for domestic boilers now.

You may not be convinced that operating in condensing mode but it will save 10-20% of energy costs on a well designed system, it sounds as though perhaps your's wasn't correctly sized for the thermal properties of the house.

I thought hot water tanks were supposed to be at least monthly heated to 60 for legionella? Do boilers not automatically vary the output temperature depending on the house temp. so when the house is cold the output temperature is high to minimise heat up times then drop to 50 when up to temp?

[eliot]

herewego said:

I thought hot water tanks were supposed to be at least monthly heated to 60 for legionella? Do boilers not automatically vary the output temperature depending on the house temp. so when the house is cold the output temperature is high to minimise heat up times then drop to 50 when up to temp?

I heat the tank to 60'c once a week (And for the Sunday washing up) - otherwise I only heat it to low 50's. I use home automation for everything, so all setpoints are software defined with hardware failsafe (the original tank thermostat is in series effectively, so if the s/w goes haywire the physical thermostat will cut in just above 60'c)

Interesting that you say i've used 50% more gas, As i said, I've got nothing to baseline against. You wouldn't want to see my electricity, that's in the £100+ a month.

[herewego]

eliot said:

herewego said:

I thought hot water tanks were supposed to be at least monthly heated to 60 for legionella? Do boilers not automatically vary the output temperature depending on the house temp. so when the house is cold the output temperature is high to minimise heat up times then drop to 50 when up to temp?

I heat the tank to 60'c once a week (And for the Sunday washing up) - otherwise I only heat it to low 50's. I use home automation for everything, so all setpoints are software defined with hardware failsafe (the original tank thermostat is in series effectively, so if the s/w goes haywire the physical thermostat will cut in just above 60'c)

Interesting that you say i've used 50% more gas, As i said, I've got nothing to baseline against. You wouldn't want to see my electricity, that's in the £100+ a month.

I may not want to see it but you should be looking into it, £100/month is nuts.

[MJNewton]

Yes, that does sound nuts. There must be something unusual about your electricity demands to lead to such high consumption?