Lowering heating bills

[old martParticipant @oldmart]

Not long ago I watched a tv programme on smart meters. At the end there was a tip for people with gas condensing that promises to save costs. I check this out online and the general concensus is to reduce the temperature of the heating flow to 60C. I lowered my Worcester Bosch 4000 from 65C to the recommended 60C and hopefully the gas used will drop. The noticable difference is that the boiler runs longer than it did,but at a lowering of the water vapor coming from the exhaust which is easily visible from the kitchen.

Has anybody tried this long enough to comment on any savings there might be?

[howardbParticipant @howardb]

Joining this thread I cannot offer any hints or tips for running heat pumps, or gas heating appliances, as we don’t have any advanced tech like that.

This is our fourth house since getting married, since the 70’s the previous three new  houses were conventional UK mains gas, wet systems, radiators, hot water etc.

We had problems with every UK house that had a wet gas fired heating system, bad installation, leaks, electrical problems etc.

So decided we would not seek to emulate our previous UK heating “advantages” when we moved to France.

Here we use a mixture of kerosene, wood and electricity to heat our house and provide hot water in north west france.

The kerosene we buy anywhere, diy stores,supermarkets, if it’s a good price, to use in heaters that are not generally known about in the UK – 100 % efficient, bur very popular in Japan.

https://www.qlima.com/heating/liquid-fuel-heaters.html

The wood we use,is some of our our own from fallen dead trees in our own woodland, mixed with bought in wood from commercial suppliers and is keeping us warm right now.

For the bathroom. shower room,bathroom and bedrooms we use electrical inertia heaters if necessary to top up the heat.

If the electricity fails, we have a generator so the kerosene heaters will still work.

That’s how we live where we are now.

 

 

[PlasmaParticipant @plasma]

<p style=”text-align: left;”>I can see how the “system” you currently use in France works for you.</p>
But it’s dependent on a number of things that make it look pretty inconvenient compared to central heating.

Firstly, not many people in the UK have access to free wood from their own woodland. The way planning permission is being axed by Labour means more houses being built with no green space whatever, let alone areas with trees.

Secondly,  sourcing and carting flammable liquid around doesn’t seem very safe or convenient.  Don’t get me wrong, I recall being sent for a can of esso blue paraffin when I was a child, to fuel our Aladinique paraffin heater in the bedroom. But I also recall the smell of it pervading the house both when filling and using the heaters.

I also have a back up generator at home as a just in case for possible power cuts, I bought it from the son of a guy who got it in the 70’s for the same reason.  I’ve never used it during a power cut and neither did he, so national grid must be doing better than EDF.

But if it works for you then very good, it just sounds very low tech and labout intensive, the wood wont cut, carry and stack itself. I too have a multi fuel stove but that heats only one room and has no back boiler. But I don’t fancy carting wood and coal around as I step into later life.

A properly installed and maintained wet central heating system is no more trouble than household plumbing. Not many properties would advocate having a well in the garden in case the mains went off.

I’m not bashing your efforts to heat your home in france in a way that’s different to what we are used to in the UK. But its not possible or convenient over here. As an eight year old I remember being regularly told to throw in a ton of coal for Mrs. Tomlinson before I had my tea. Can you imagine saying that to our crop of offspring?  We have a twenty year old volunteer at our community garden and that task would take him a day to complete based on watching him struggle to use a shovel.

As I said, if it works for you then it’s fine, but your circumstances are very different to many.

 

 

[Robert Atkinson 2Participant @robertatkinson2]

Two problems with self-contained combustion heaters:

They generate LOTS of water vapour

In the case of fault they can generate carbon monoxide.

Robert.

[SillyOldDufferModerator @sillyoldduffer]

My feeling is physics are against Old Mart achieving significant savings by altering his boiler.

Web advice is based on the observation that many condensing boilers are set to a compromise.  If a condensing boiler is set to maximise heat recovery which goes to the radiators, then the hot water system is a shade too cool, especially if an immersion heater tank in in the system.

Older gas boilers were a little over 80% efficient, with a good proportion of wasted heat going out the vent as exhaust.  A condensing boiler recovers up to about 12% of the heat, less if compromised in favour of hot water.  Problem is the percentages don’t leave much room for improvement:  I guess a boiler aggressively tuned in favour of hot water might squeeze another 4%, but most of us would get less.  Is it worth it?

There is another problem: Wikipedia explains condensed water becomes more acidic as heat recovery is optimised, requiring the condenser to be designed to cope with it.   May not be wise to adjust a boiler to save a few quid if doing so reduces the life of the boiler by excessively acidifying the water.

Personally, I look to other methods!

• I run the heating at 18°C and wear a jumper!  Heating at a lower temperature saves big money.
• The house is well-insulated and double-glazed.
• The heating only comes on for a few hours to get me in and out of bed and showered etc.  It’s rarely needed when I’m moving about.
• The radiators are switched off in little used rooms.

May not work for you!  The female of the species, older folk, and those with limited mobility or sick, may well find 18°C too chilly.   Older houses are often difficult to insulate, and may be damp too.  There are no ‘little used rooms’ in a family home!  My mum and ex both swear by their electrically heated throws – a few watts keeps them toasty in front of the telly and whilst doing their indoor hobbies.

When my boiler has to be replaced I shall look seriously at a heat-pump.   More expensive to install, cheaper to run.

Dave

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

Two problems with self-contained combustion heaters:

They generate LOTS of water vapour

In the case of fault they can generate carbon monoxide.

Robert.

I agree with both points – but these so-called inverter heaters are poles apart from any paraffin heater you have memories of, widely used in rural france, the fuel is available in all supermarkets and diy shops, the last lot we bought cost about £1.10/litre and will run on a full 5 litre tank for 37 hours on low output or 16 hours flat out at 3.0 kw.

I realise that if you burn 5 litres of hydrocarbon fuel you generate roughly 5 litres of water vapour, but we have never had a problem with it.

They modulate their output automatically, very quiet, don’t smell, probably because the fuel is a very refined kerosene, the fuel tank is removed to fill it so no spills in the house, the fuel delivery is via a metering pump to the burner which has no wick, controlled electronically, including a timer, automatic ignition via glow plug, very low electrical power consumption -300 watts during the ignition sequence for 3 minutes, 15 watts when it’s running and has automatic room air sampling with alarm and shutdown, also has self diagnosis with fault codes displayed on the led panel.

The biggest advantage is that if they break down, you just go buy another one at 200-300 euros – no messing about with finding reliable plumbers etc.

https://shorturl.at/QCVb5

(read the reviews)

We have one spare 3.0 kw model so can swap over in minutes if either of the two house heaters go u/s which hasn’t happened in the 12 years we’ve been running them.

And – they are made in Japan.

[John HaineParticipant @johnhaine32865]

I was puzzled by the numbers, but 16 hours x 3600 seconds x 3200 watts – 184 MJ.  Energy density of kerosine is 35MJ/litre so 5L gives 175 MJ, about right.  If you’re worried about the water vapour then running a dehumidifier ar 500 watts will absorb it, give you rather more than 500W of heating (specific heat of vaporisation helps you), and a supply of soft water for your steam iron / model loco / traction engine.

[Graham TitmanParticipant @grahamtitman81812]

The other problem in uk most new houses don’t have a fireplace or chimney and are in smokeless zones

[duncan webster 1Participant @duncanwebster1]

Buying paraffin in UK shops is more expensive than petrol. Probably cheaper in bulk.

[howardbParticipant @howardb]

Replying to Plasma.

There are a few reasons why we don’t have a conventional wet central heating system.

The house is an old stone property which was extended, renovated and plasterboard lined and insulated by the previous brit owners.

The granite walls in the 100 year old house are a metre thick in places, built in rubble stone/lime mortar and we just didn’t want the cost, disruption and mess involved, plus the layout doesn’t lend itself to that sort of heating.

No mains gas available like most of rural france so if gas ch would have to be LPG tank gas – very expensive in france, both the tank and the gas contract.

That leaves oil, which in France is the same as non-road diesel – gasoil.

That didn’t appeal – smell – annual servicing, cost etc.

The house already had a woodstove in the lounge diner and a Rayburn in the kitchen, we replaced the Rayburn with an Esse Ironheart multifuel cookstove the first year we were here.

The other option would have been to go 100% electric heating which a lot of french homes still use, but has got increasingly expensive, and a lot of rewiring and increasing the mains power input – puisssance – the usual maximum in france is 18 kva for residential property on the base tariff, we manage ok on 9 kva with two 1 kw inertia radiators and two 500 watt towel rails in bathroom and downstairs shower room, and 1.8 kw overnight water heating on cheap rate.

The possibility for the future is wood pellet heating as a room heater, easier to get the fuel in, available delivered on a tonne pallet of 15 kg bags, I’m investigating this to find a decent installer to sort out the flue and installation,  pellet heating is getting very popular in France as the wood pellets are readily available and cheap – €4.50 per bag in supermarkets ATM.

We’ll see how that goes !!

 

[duncan webster 1]

On duncan webster 1 Said:

Buying paraffin in UK shops is more expensive than petrol. Probably cheaper in bulk.

The Zebro heaters can use C1 paraffin in the UK, but as you say it’s expensive as some friends of ours found out when they returned to the UK with their heater.

[John HaineParticipant @johnhaine32865]

We rented an AirBNB in Jard sur Mere in October 2023 for a few days which had a wood pellet heater.  Lots of heat but rather like sharing your sitting room with a jet engine because of the fan!

[duncan webster 1Participant @duncanwebster1]

Be careful with wood pellet.they might have improved, but 2 installations I know of you can’t regulate the output, if you try to turn it down the fire goes out. Only way to reduce temperature is to open the windows. Granted these are from quite a long time ago

[John Haine]

On John Haine Said:

We rented an AirBNB in Jard sur Mere in October 2023 for a few days which had a wood pellet heater.  Lots of heat but rather like sharing your sitting room with a jet engine because of the fan!

I should add, the noise not the draught!

[Robert Atkinson 2Participant @robertatkinson2]

Did a bit of reseach into the liquid fuel space heaters.

At least one insurance company says you may not be covered to use them see section 2 of
https://riskadvisor.zurich.com/documents/rt_gas_and_oil_fired_space_heating.pdf
This probably applies to the use of “diesel” heaters designed for use in vehicles.

A CE declaration of conformity I found covered Low Voltage, EMC and RoHS dbut nothing related to heating for example Regulation 2015/1188. It is part of the EU’s Ecodesign Directive 2009/125/EC that sets environmental standards for all energy-consuming products.
https://media.adeo.com/media/1370575/media.pdf

Use at your own risk.

Robert.

 

[old mart]

On 14 March 2025 at 20:59 old mart Said:

Not long ago I watched a tv programme on smart meters. At the end there was a tip for people with gas condensing that promises to save costs. I check this out online and the general concensus is to reduce the temperature of the heating flow to 60C. I lowered my Worcester Bosch 4000 from 65C to the recommended 60C and hopefully the gas used will drop. The noticable difference is that the boiler runs longer than it did,but at a lowering of the water vapor coming from the exhaust which is easily visible from the kitchen.

Has anybody tried this long enough to comment on any savings there might be?

 

I suspect that also depends on the type of boiler? Newer types have (or can have) proportional gas valves, which adjust the flame size to control the heat output.

Older ones such as mine (which is still an A rated condensing one) just cycle on and off at a different temperature.

 

The most important DIY adjustment on a normal UK water + radiators heating system is to make sure the lockshield valves on the radiators are set appropriately. They are often set fully open on some or all, which means the water is just circulating through without time to cool down.

The return water to the boiler should ideally be something like 25% cooler that the boiler output, so 80 down to 60C or 60 down to 45C etc.

It only takes a single radiator set wide open to allow most of the boiler flow to bypass the rest of the radiators that are set for restricted flow as they should be.

 

You can adjust the valves so the radiators just have a just noticeably cooler (but not cold) area in the middle at the bottom. That means the water is staying in the radiators long enough to give out a reasonable proportion of its heat.

That flow is typically with the lockshield valve about half a turn away from fully closed! Though it does need adjusting for each radiator.

(Turn the manual or thermostatic valve to fully open or maximum while doing the tests, and start with the system cool).

 

[vintagengineerParticipant @vintagengineer]

We live in Perthshire, big tree country. The UK government want to ban wood stoves as they cannot tax firewood. We get all our firewood as waste from the local sawmill at a very reasonable rate.

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

Did a bit of reseach into the liquid fuel space heaters.

At least one insurance company says you may not be covered to use them see section 2 of
https://riskadvisor.zurich.com/documents/rt_gas_and_oil_fired_space_heating.pdf
This probably applies to the use of “diesel” heaters designed for use in vehicles.

A CE declaration of conformity I found covered Low Voltage, EMC and RoHS dbut nothing related to heating for example Regulation 2015/1188. It is part of the EU’s Ecodesign Directive 2009/125/EC that sets environmental standards for all energy-consuming products.
https://media.adeo.com/media/1370575/media.pdf

Use at your own risk.

Robert.

 

Thank you for your concern Robert but all that applies to you using said heater in UK

The heaters we are using are certified to NF – Norme Francais

So is the fuel – not allowed to be sold unless approved to NF.

The heaters and the handbook are also marked NF.

[Robert Atkinson 2Participant @robertatkinson2]

Actually CE does not apply in the UK, we left the EU…

NF’s are standards not the regulation you can show compliance with the regulation(s) by complying with the requirements of the standard not the other way around. Your heater should have a CE mark. Any NF number quoted is just for reference. France cannot prevent the sale or use of a item CE marked in another EU country even if they don’t use NF standards. Most of the relevant stanards are euro norms (ENs). Typically these are “nationalised” by the addition of a prefix. For example EN60335-1 becomes BS EN60335-1 (British Standard) in the UK and NF EN60335-1 in France. Most are published by AFNOR in France.
The CE DoC I linked to is from a Dutch company. The fact that an importer is writing a DoC is another red flag as it tells us that the unit was not designed and manufactured for CE compliance. If it was the manufacturer would have marked the item and issued the DoC.
Water vapour, fire and carbon monoxide don’t care what country they are in….

Robert.

[duncan webster 1Participant @duncanwebster1]

Best way of reducing heating bills is to buy a thicker jumper. My father in law used to insist on having the whole house hot enough to just be in shirtsleeves, which was a pain on the butt in winter as you had to strip off every time you went indoors. We wear thick jumpers and only heat the rooms we’re using, and as I’m bald as  a coot I wear a hat indoors, to keep warm, not for religious reasons.

[howardb]

On howardb Said:

On Robert Atkinson 2 Said:

Did a bit of reseach into the liquid fuel space heaters.

At least one insurance company says you may not be covered to use them see section 2 of
https://riskadvisor.zurich.com/documents/rt_gas_and_oil_fired_space_heating.pdf
This probably applies to the use of “diesel” heaters designed for use in vehicles.

A CE declaration of conformity I found covered Low Voltage, EMC and RoHS dbut nothing related to heating for example Regulation 2015/1188. It is part of the EU’s Ecodesign Directive 2009/125/EC that sets environmental standards for all energy-consuming products.
https://media.adeo.com/media/1370575/media.pdf

Use at your own risk.

Robert.

 

Thank you for your concern Robert but all that applies to you using said heater in UK

The heaters we are using are certified to NF – Norme Francais

So is the fuel – not allowed to be sold unless approved to NF.

The heaters and the handbook are also marked NF.

I’m intrigued.  Which standard(s) do the NF mark on Howard’s heater refer to?  I can’t find one in the NF list that covers heaters of any kind.

I don’t care if Howard chooses to manage the risk of operating a paraffin heater, but I suggest he shouldn’t put much faith in NF or any other marking!

The amount of water vapour produced is a problem and oil heaters caused more than their fair share of fires and burns.  Worst of all, Monoxide poisoning:  usually after a heater has aged, not been maintained, damaged, covered, or operated outside the manufacturers recommendations.   And maybe being bought for cheapness led some owners to carry on using them long after they were out of spec – to save money.

In my youth paraffin heaters caused a lot of problems in the UK, so they went out of fashion and were discouraged by legal changes, such as taxing the oil.  As their main advantage was cheapness, increasing the cost of paraffin encouraged people to find alternatives, all safer.  In contrast, electric heaters are virtuous.  No water vapour and no monoxide.  They can and do catch fire and electrocute, but electric heater accidents are rare compared with paraffin.

Dave

[Robert Atkinson 2Participant @robertatkinson2]

Hi Dave,
The French standard for domestic freestanding oil heaters is NF128
https://www.eurovent-certification.com/media/document/program/57/57/57438fd87fdff22329fa0fd273d814c2/S08%20D01%20NF%20128%20R%C3%A9f%C3%A9rentiel%20technique%20Rev%2016%20approv%C3%A9_en-GB.pdf

The NF for heating oil is NF M15-008 https://www.boutique.afnor.org/en-gb/standard/nf-m15008/liquid-mineral-fuels-domestic-heating-oil-requirements-and-test-methods/fa196461/84837

Not sure how NF128 marking fits in with CE. I suspect it is just a standard to meet the efficency requirements. There is a registry of “approved” models https://www.eurovent-certification.com/en/third-party-certification/certification-programmes/nf128

Interstingly for QLIMA models they list the country of manufacture as Netherlands for most models, some Japan and some China. So they are not “made in Japan.
https://www.eurovent-certification.com/en/advancedsearch/result?program=NF128&product_type=NF128%2FSRE&keyword=#access-results

It appears that there is only one laboratory that can “apply” the NF mark for NF-128. If the French laws insist on this NF mark it would appear to be a breach of EU open market regultions. It may be that legally a CE mark is acceptable but local market forces mean the NF mark, while not legally required, is needed to sell the product.

As an aside I work with a committee in France (we have meetings in St Denis were the WWII bomb was found a couple of weeks ago) on a harmonised pair of European / North American technical standard)

Robert.

 

 

 

[Phil SParticipant @phils66830]

I changed to a modulating condensing gas boiler. It is great but took a lot of work to optimise efficiency. Could not see what was going on until I fitted a pair of pipe thermometers which were useless until refitted with thermal paste. Spent time balancing radiators to get return temperature minimised. This means boiler will run longer but more efficiently. The max boiler temperature setting cannot be below around 65C if the hot water tank is to be satisfied in a resonable time. I heat hot water in two sessions, early morning and mid afternoon during which central heating is off. Central heating return is delayed 30 minutes after hot water so very hot aluminium heat exchanger does not get shocked by cold radiator water.

[NealebParticipant @nealeb]

My understanding is that in an older manual-valve-only radiator system, then you should (or the installer should but probably never does) set up the system by opening all the manual valves fully, then adjust the lockshield valves in each room until eventually each room is taking an appropriate proportion of the circulating hot water. To adjust the system for the appropriate return pipe temperature, this presumably needs all the LS valves opening/closing in the correct proportions to adjust the total flow volume. The effect of closing the manual valve in, say, an unused bedroom will unbalance this setup but presumably not by too much to matter. Somewhere there is also a single room temperature thermostat which will respond to the temperature in that one room but will turn on or off the heating in all rooms. So far so good? However, this setup takes no account of things like solar heating, which will vary between rooms, time of day, as well as amount of sun. So the “balanced” room temperatures will be a bit of a compromise.

Now we move to the more current situation of mechanical TRVs on all radiators. This is the point where I start to wonder about the role of the LS valve. Whether fully or partially open, the room will (providing the LS valve allows enough hot water to pass) get to temperature and then the TRV will close (partially, I guess) to reduce the flow in that radiator. Assuming that we are heating the house from cold, then the LS valve will alter the rate at which a room heats up, but has little influence on the end-point temperature. So if the LS valves are open by different amounts, we can affect the rate at which rooms heat up, but not really have much effect on the temperature once stable. Again, I presume a single room thermostat – in a room with no TRV? – to shut down the boiler when the target temperature is reached, or else we could imagine the boiler and pump running with all TRVs shut under certain circumstances. Not desirable? But we can cope better with solar input, etc. Should we fiddle about with the LS valves to adjust total flow to get the desired return temperature, or is this a waste of time as it will vary with the total radiator demand as controlled by the TRVs?

When I moved to my current house, I was surprised to find that there were TRVs on all radiators, a time switch, but no room temperature thermostat. I have no idea how that was supposed to work but presumably someone felt that there would be at least one radiator open at any time. I fitted a room temp thermostat fairly soon after I moved in.

The most modern form of TRV is a wireless valve which does not have any proportional opening – it’s fully open or fully shut. I have now fitted these in my own house with a central controller that can provide what amounts to room-by-room temperature and time programmes. So, main bedroom and bathroom come on first, followed by kitchen a little later, followed by whatever. Bedroom goes off and stays off until bedtime. By “off”, I mean that the temperature is allowed to fall to a predetermined setting. This system copes with solar input, etc, as all control is room-by-room. The documentation also tells me that the controls having a “learning” feature that allows them to set “on” times to account for how quickly a room heats up. And, of course, there are the expected “control it all over the internet” features to allow me to regulate things from a distance.

So how do you control return temperature, use LS valves, and so on, to get the best out of a modulating condensing boiler in this situation? Not having such a boiler it’s a bit academic at the moment but I know that my system can provide an interface box to make use of one.

All the above represents my best understanding of how things work but based somewhat on conjecture – I look forward to hearing from the experts!

[simondavies3Participant @simondavies3]

Thank you for your concern Robert but all that applies to you using said heater in UK

The heaters we are using are certified to NF – Norme Francais

So is the fuel – not allowed to be sold unless approved to NF.

The heaters and the handbook are also marked NF.

Howard, you have a PM.
Simon

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