Boiler / Radiator Total BTU Advice Needed

[Pgeddon]

With regards to zoning or further controls I'm assuming not every rad equates to a room but do they all need to be fully heated? At least consider fitting TRV's and or smart thermostats, whether just by heating zone valve 1 or rads with low set TRV's you will use less gas as the boiler will trim down due to less demand.

Yes that's the point I was eventually getting to - Ultimately if I had an engineer come do some invasive work to access the pipes and separate the downstairs (Zone1) and Upstairs (Zone2).

By only having Zone 1 ON.....is that basically exactly the same as having 12 of the radiators turned off at their TRV's?

...And either of those would automatically mean the boiler is working less hard and using less KW per hour, despite it being cranked to max? Likewise as we've currently got 7 radiators blanked off....should that be costing us less per hour by the same logic?

 

[gmartine]

If you're only trying to heat half the number of radiators by zoning you will naturally use less gas than you would by trying to heat all of them.

TRV's are either manual or smart and are a means of controlling individual room temperature. Your radiators will already have a means of closing them by using the valve (lock shield) at either end which I assume you have used to blank some of them off.

Setting the boiler to MAX set's the flow temperature to maximum however the lower the temperature you can run the boiler the more efficient it is and the less gas you will use as long as demand from your radiators can also be met.

 

[king of pipes]

Yeah I'd like it to be at 65c too for the obvious benefits, though i think if we hadn't had it cranked to MAX over the cold winter the house would've been difficult to live in. I feel in a bit of a catch22 with it as even with the boiler on MAX and run often the house still wasn't warm, despite the complete lack of efficiency in operating this way.... though as you say its good that the insulation is happening and in hand, hopefully that does make a notable difference. (mostly 400mm wool in the loft floor now).

RE: zones, I have a potentially silly question, apologies if it is, but is the below correct?

:-If the property was split into 2 zones, for simplicity of maths lets say of the 24 rads...
Zone 1 = 12 rads,
Zone 2 = the other 12 rads.

If I cranked the boiler to MAX but only had Zone 1 ON, Would that cost me less £ per hour to run the boiler Vs how its setup currently with no zoning? as it'd be feeding fewer radiators?.... or does the boiler just cost the same to run per hour regardless? (again sorry if this is a silly question)

Basically yes you will be heating fewer radiators and controling the temperature of each zone, if Trv valves are fitted then they can be controlled individually aswell unoccupied rooms or rooms which are use less can be kept on a minimum setting .

 

[Pgeddon]

If you're only trying to heat half the number of radiators by zoning you will naturally use less gas than you would by trying to heat all of them.

TRV's are either manual or smart and are a means of controlling individual room temperature. Your radiators will already have a means of closing them by using the valve (lock shield) at either end which I assume you have used to blank some of them off.

Setting the boiler to MAX set's the flow temperature to maximum however the lower the temperature you can run the boiler the more efficient it is and the less gas you will use as long as demand from your radiators can also be met.

Basically yes you will be heating fewer radiators and controling the temperature of each zone, if Trv valves are fitted then they can be controlled individually aswell unoccupied rooms or rooms which are use less can be kept on a minimum setting .

Yes, thanks - that's what I assumed..... but what i've monitored today didn't quite add up to that so left a little confused.

Early January I did a quick measure of how many M3 of gas we were using per hour when I put the Central heating on...back then the CH on for one hour was using about 3.5M3 per hour (38.5kw/hr -ish?)..... between then and now we've blanked off 5 radiators, but I measured it today and we're still using about 3.1M3per hour (33kw/hr-ish?).

With a good 25% of the rads now not in the circuit i'd have expected it to drop much further? Could this mean there's a problem somewhere or does this amount of difference seem normal to you guys?

I ask because my proposed zoning would be essentially to eliminate 12 out of each zone, so i'd hoped that when using either zone it'd roughly half the amount of M3 my boiler would be using, and halfing the cost per hour to run it?

What have I missed? haha

 

[king of pipes]

Your missing the fact that when all the rads were working your home would heat more quickly and switch off sooner but more rads heating equates to more gas used
Take away 25% of the radiator output then your boiler will struggle to heat your home to a comfortable temperature so be on longer your compensating by running it at a higher temperature and probably still not achieving the comfort level you require? this will use more gas
You will not see savings until your work is completed as I said unless you invest and are able to heat the property and hold that temperature you may not see a saving at all ? the boiler needs to run for a shorter lengths of time and or at lower temperatures zoning and adding more control of individual areas and rooms will see savings but , insulation, draught proofing, heavy lined curtains , keeping doors closed anything that uses power switch off changing the habits of a life time really, you could get a energy performance inspection done this will give you a good idea of how efficient your home is and what improvements could be made to use less energy and get you savings it not that expensive under £100 in most cases . Regards Kop

 

[gmartine]

Also, despite closing seven radiators there's no indication of their output, room size and therefore heatloss as a proportion of the rest of house so loss comparisons won't necessarily be as proportional as you expect. Every improvement suggested will help but if you really want to accurately drill down into your gas use metrics then a smart TRV based system maybe the way to go.

 

[gmartine]

Also, despite closing seven radiators there's no indication of their output, room size and therefore heatloss as a proportion of the rest of house so loss comparisons won't necessarily be as proportional as you expect. Every improvement suggested will help but if you really want to accurately drill down into your gas use metrics then a smart TRV based system maybe the way to go.