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Post by MikeMusic on Nov 7, 2022 15:58:42 GMT
You may have seen the raft of information recently, (possibly influencer hype) about turning down the boiler temperature* to ensure that boilers are working in condensing mode and hence at their best efficiency. The premise is that many UK condensing boilers are oversized and hence the water returning to the boiler is still too hot to allow condensing. Eventually the boiler will stop heating even though a simple on/off room thermostat** is still calling for heat. in the worse case, the boiler will constantly be cycling on and off either at the boiler or because the house is close to the set temperature The set me thinking, for the sake of argument, if the cost of gas has doubled, using half as much as previous years should keep you inline with previous budgets, but, how best to use this reduced amount of gas to get the best effect? These are my current musings which assume that your current settings were as lean as possible 1. Heat losses increases significantly with the size of the temperature difference between inside and outside which is why turning down the thermostat works so well (i.e. 18 rather than 20) 2. Would "pulsing" the heating improve efficiency while maintaining some level of comfort? instead of having the heating on for say 4 hours from 18:00, maybe two one hour bursts or four 30 min bursts would maintain some comfort but improve efficiency since the boiler has more work to do since it is heating a colder house and not cycling 3. How you use this half-energy approach depends upon your personal circumstances... Is the house empty during the day etc. It would be a shame to have residual warmth in the house when you are asleep or out 4. Personally, while I find being wrapped up in a blanket fine on the sofa, late in the evening while watching telly, I find it very hard to work at my desk with a cold house and bundled clothing. * the adjustment procedure differs for combi (no hot water tank) and system boilers **Many thermostats, even modern "smart" ones are set up only to be binary on/off switches for below or at/above the desired room temp. This means that the boiler operation is also binary....100% or off. There is additional wiring and standards (opentherm) which allow the boiler output to be modulated.... when the room needs a lot of heat, the boiler is at 100% and as the room gets nearer the required temp, the boiler output is reduced. This improves efficiency and boiler lifetime. External sensors, (weather compensation) can also be used to help with this. Still trying to understand how adding an external weather compensator will save so much Have watched a couple of YouTube videos but it still baffles me Get past the accent or put subtitles on  |
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Post by MikeMusic on Nov 7, 2022 16:01:45 GMT
The house that makes a profit exporting energy
So much tech
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Post by julesd68 on Nov 7, 2022 20:30:56 GMT
The moral of the tale is to have your boiler serviced every year and not skip a year like we did! Thanks for the reminder - couldn't get someone to do it last year so it's well overdue and haven't got round to it. |
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Post by speedysteve on Nov 7, 2022 21:01:25 GMT
You have to get the right people to service the boiler🙂
We had seemingly good plumbers do the install of Worcester Bosch and Polypipe underfloor heating.
Apart from a few teething troubles (one thermostat not physically plugged in, so it couldn't call for heat, and two of the bedrooms switched about, so bedroom A called for heat and it went to bedroom B etc🙄), all seemed fine.
They serviced boiler every year.
Then the reset light started to illuminate and manual intervention was needed to get it going again.
They looked at it but ultimately didn't know how to fix it.
That was 3 years into the 5 year boiler warranty.
So, out came Worcester Bosch.
It turned out to be a 'master' and apprentice on training.
The master let the apprentice try to figure out our problem, with some guidance.
They changed all manner of things, new PCB, sensors, switches etc.
The master kept taking the apprentice back to the service schedule and notes.
Eventually he figured it out.
The service plumbers had been checking the CO2 level, all seemed fine / signed off.
BUT they only checked the max allowable.
The minimum threshold was set so low that an efficient burn could not be had, sensors tripped, reset light illuminates, boiler stops!
Also it's 24kwh couldn't pull the skin off a rice pudding!
I had to protect the water cylinder heat cycle from the heating as doing both resulted in both being tepid!
It was so weak.
Plumbers🙄 no help!
Once that was adjusted the boiler has never missed a beat.
Burns like the Rocinante🙂
I never used the plumbers again (father and son) and call them Dumb and Dumber forever more! 🙂
The other thing with modern pressure system boilers is the Pressure Vessel!
Whilst you can easily top up the water level, air can leak out of the crappy Schrader valve. Just like a cars tyre.
Not do easy for lay people to understand.
The diaphragm can be pushed completely over to the side by topping up the water side pressure.
Once there's no more diaphragm movement possible in the pressure vessel, the boiler operates on the pressure relief valve.
Your nicely set 1 bar becomes 3.5 bar when hot and water is discharged (to prevent a big bang), and then the pressure gauge shows 0 bar when it's cooled down!
One 'might' top the water up to fix the gauge reading and so the cycle goes on.
But where does the water go? They presumably think it's leaking somewhere invisibly and ignore it and sell the property😂
Service plumbers don't seem to check the air pressure in the pressure vessel! Ours never did!
1 bar odd for the boiler, perhaps 3 bar for hot water pressured cylinder.
I learned all this with daughters flat.
Having figured it out, all that was required was a new car tyre valve and a pump up to 1 bar - simples.
Now I check ours regularly, cos plumbers don't.
They only talk of the pressure vessel failing = replace, which earns them real money!
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Post by julesd68 on Nov 7, 2022 21:57:59 GMT
I remember one year paying for an 'official' Vaillant service - the engineer was in and out after around 15 minutes. How on earth can the boiler be adequately checked in that time? Cost around £80.
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Post by MartinT on Nov 8, 2022 6:09:23 GMT
the engineer was in and out after around 15 minutes That's outrageous. Our guy was here for almost 2 hours cleaning every part of the boiler and reassembling it. They issued a proper Oftec CD/11 test certificate at the end of it, too. |
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Post by MikeMusic on Nov 8, 2022 10:45:10 GMT
There's plumbers and plumbers like so many trades
Finding a good tradesman is often a matter of luck or keep trying another
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Post by julesd68 on Nov 8, 2022 11:31:07 GMT
I wasn't expecting a full strip down and rebuild at that price but it was a complete piss take. And that's from the people who make the boiler!
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Post by ajski2fly on Nov 9, 2022 11:58:38 GMT
Just in case anyone keeps their heating on through the night Don't We always have the window open at night. Internal door closed so the rest of the house doesn't lose heat I doubt anyone here believes it saves money to leave the heat on permanently, a lot do, it 100% does not. Programme heat to go off 30 minutes before expected bed time, maybe longer, will experiment with that I contacted Passivhaus to ask if they had a specialist contractor to look over draughts and improve insulation "Check out or list" was not helpful as architects and big builders. There must be a draught and insulation improver somewhere passivhaustrust.org.uk/members/map/A thermal survey to find out where your heat is lost Cost me around £400 10 years ago. Well worth it and leaks in very surprising places Our existing cavity insulation is not that good. Apprehensive at having it replaced and also reluctant to go for insulated cladding on the outside.... Opening windows at night when colder outside really is not a sensible approach to heating a house. The heat already in the house wil be lost though the open windows, negating any insulation. The further the temperature drops inside the more power will be required when the heating is switched back on to get the house back up to the required temperature, this is basic physics. The whole point of insulating roofs/walls and having double or triple glazed windows is to stop heat escaping and keeping as much heat in the house as possible and maintaining an even temperature. Our house with an Air Source Heat pump(ASHP) fluctuates between 19.5c at night and 21.5c during the day at present, if the heating drops below 17c at night then it automatically kicks in, this has only happened a couple of time when about -5c outside. The heating goes off at 21:30 and then kicks in in the early hours of the morning to raise the temperature back to 21.5c by 6:00am, this is determined by the system based on external & internal temperature monitoring. The heating is set to go off 9:00am and comes back on at 16:00, our bungalow gets sun on 3 sides throughout the day and at present the house temperature rarely goes below 20.5c from 9:00 to 16:30, a combination of the sun and insulation. During the day the heating is set to come back on if the temperature inside drops down to 20c, even in the middle of winter we only had about 10 days when this occured. The image below shows the actual heating usage for yesterday, the green is the pre-heat I mentioned, red is when it is raising the house temperature back up.  The image below shows the electric from solar generated and exported, imported power figure is primarily between 23:30 and 5:30 at cheap rate off 7.5p/kwh on Inteligent Octopus, this is when it is recharging the battery back up to 20Kwh stored, any other house power usage during this time is at the same rate. During the day the batteries run the house until 20kwh is used up and then it is 41p/kwh. We rarely use up the 20Kwh store, this tends to only happen on a poor Solar day if combined with washing and using the tumble dryer. We put the dishwasher on after 23:30 using a timer, when we replace the tumble dryer this will have a timer and be a very efficient heat pump type which use half the power of a traditional a rated one.  We know from our heating bill for the past year, and daily observations during the winter that on average on the coldest days our peak usage is 25-28Kwh, so the worst case scenario is 20Kwh at 7.5p/kwh and 6-8Kwh at 41p/kwh. so a maximum daily cost of £4.78. However I know that even in winter on a 50/50 solar day we will generate 4-8kwh so actually we are more likely to have to pay £1.5-2.50/day for power. We are expecting our highest electric bills in December and January to be in the order of £60-80 for each month. October usage was 332Kwh at £24.20, November is looking to be around 450kwh, £34. Based on last years usage without the battery storage in December and January we anticipate grid usage will be around 640Kwh from the grid based on only 20% Solar generation, around £50 at 7.5p, but it is more likely to be around £80 due to poor solar days. The reason I have put the above up is to demonstrate, as I have found out, it is important to understand how your heating works and how it is best to optimise it. All the people I have spoken with over that last 3 years in relation to saving on power usage have highlighted the points below atone time or another, this has been backed up on everything I have read as well before putting in Solar, batteries and a ASHP. 1. Before anything else insulate the house as well as possible and as much as possible, address roofs, walls and windows, this is the most cost effective thing to do. The more a house leaks heat the more costly it will be to run whatever the heating system is. Do not vent the house unnecessarily, do so when the outside temperature is at it highest in the day. 2. Set the heating to try and maintain an even and warm temperature, avoiding allowing the home dropping to low temperatures, it becomes much more costly to get heat back into the property and is inefficient especially if only heating the home for short time periods. 3. If the heating system will accept it put a modern monitoring/control system in place that allows you to monitor heating and power usage. The it becomes easier to tune and control what is going on. there are many products out there the do this. 4. The sun is you friend, even in winter, pull curtains right back on a sunny day in rooms when the sun is shining into them, it is surprising how much radiant heat can be got into the home. If it is cold outside winters as the sun moves round the house from room to room, consider pulling curtains in unused rooms to give more insulation to the windows. the thicker the curtains the better or add additional innings. 5. Do not allow draped curtain to cover or fall over radiators, all you do is heat the window not the room and use more power. 6. To save on power costs if you can get on a cheap rate electricity plan for night do washing, dishwashing and drying at night, and heat up water tank. 7. Get gas/oil boilers regularly serviced and cleaned, the better they operate the less fuel they use. 8, For water based heating systems ensure they are flushed through at least every 3 years, rust and deposits in them inhibits water flow and makes the system less efficient, in its worse form can stop radiators working. 9. Turning heating off in unused rooms is not necessarily a good approach to keeping a house warm. If a room is not heated and it becomes very cold then even with the door closed (very few are thermally efficient and will not be sealed) they will suck heat into them from the rest of the house that the owner is trying to heat. It is better to turn the radiators down in each unused room and maintain a ambient temperature of 15-16c, Get some cheap thermometers for each room and check these regularly. As outside temperatures drop then slowly turn the radiators up and visa versa. 10. When not at home during the day then a balance needs to be struck between allowing the property to become a fridge, and keeping some ambient heat in it, this is especially true in winter. this really comes back to point 2. If you turn the heating off for 8-10 hours and it is 10c or below outside then if the house is not that well insulated it will quickly loose heat and getting it back to a liveable level when you come home will use more power, than maintaining and ambient temperature. The best way to determine what works and is most efficient is to take Kwh readings for different settings, until you find the optimum settings for you and your house. I hope that a lot of you are already aware of the above, if not then I hope it will be helpful, whatever you do insulate your home as much as you can, every little bit helps! |
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Post by speedysteve on Nov 9, 2022 12:52:33 GMT
Older, poorly insulated and leaky houses are very stop start as you really can't afford to heat the whole place. Pouring heat where you are not, isn't an option.
I agree with the above 100% for well insulated properties though.
With leaky houses you end up zoning and heating where you will be sitting.
Staircases in living and dining rooms always suck air/heat upwards.
Winter for most is a time to be got through.
I can't help looking at what I call 'cold features' on Escape to the country houses etc.
Seeing a front door or staircase in the living room, cold flagstone floors, single glazing, tiny electric radiators etc.
I remember one of the Escape to the Chateau owners using £10000 a year to heat the living space she was occupying from 0 (yes 0°C) to just 10! Old asmatic system, no insulation, cold stone building etc
She wore a hot water bottle strapped on, to keep herself warmish 😱
They tend to make smaller insulated winter apartments within.
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seanm
Rank: Trio
Posts: 162 
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Post by seanm on Nov 9, 2022 18:34:28 GMT
I have been experimenting through "heating via direct thermal conduction" by wearing a USB powered heated body warmer www.amazon.co.uk/dp/B08J3ZMZ8V?ref=ppx_pop_mob_ap_shareI first started experimenting with this kind of thing last year in China with a cheap/thin heated down style puffer jacket. I have previously thought that events like gigs are the worst case in terms of temperature range. You often start queuing outside in the cold and then find yourself bundled inside in the middle of a huge sweaty crowd. My idea was that a light jacket aided by power when required might be the best solution. My wife has the vest above and I have been using it around the house for the last few days and it's working well. The vest in the link above is not attractive, but it is cheap and works. It is one size and is fully adjustable via poppers and zips to release/close the extra dimensions as required. I do not particularly feel the cold, but I find it tricky when working at the computer.... I feel very bundled up before I feel warm. This seems to break this vicious circle. There are all manner of USB heated garments: All kinds of jackets, fleeces, vests, gillets, socks and even gloves |
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Post by MikeMusic on Nov 10, 2022 16:54:02 GMT
I've thought about the open window at night and come up with a compromise.
Window open bedroom only, inside door closed so the rest of the house is unaffected.
Both of us need the window open to sleep properly.
Temperature for ideal sleep is lower, around 15'c, possibly less
Ideal has to be a heat exchange unit giving us fresh air
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Post by brian2957 on Nov 10, 2022 17:28:49 GMT
I've thought about the open window at night and come up with a compromise. Window open bedroom only, inside door closed so the rest of the house is unaffected. Both of us need the window open to sleep properly. Temperature for ideal sleep is lower, around 15'c, possibly less Ideal has to be a heat exchange unit giving us fresh air Same here Mike. Our bedroom window is opened when we go to bed, doesn't matter what the outside temperature is, and it can get pretty cold here in the winter. We need fresh air when we're sleeping |
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Post by speedysteve on Nov 16, 2022 13:20:48 GMT
Do you guys have trickle vents on your windows?
Not possible to balance heat retention and ventilation that way?
More controllable - depends on the style though.
Airflow meters, humidity tracking, lots of spreadsheets and endless adjusting possibilities, or automate😂
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Post by MartinT on Nov 16, 2022 18:08:32 GMT
Yep, we have tiny vents that do the job. No way we're opening windows to blow a gale of freezing air through the bedroom.
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Post by brian2957 on Nov 16, 2022 19:56:55 GMT
Nope, no vents here. Only option is an open window |
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Post by MikeMusic on Nov 16, 2022 20:42:33 GMT
We have trickle vents. Not enough
Window/s open at night only
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Post by petea on Nov 16, 2022 22:15:00 GMT
The advantage of living in a property built in the 17th century is that 'trickle' ventilation came as standard on all of the doors and windows!  |
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Post by julesd68 on Nov 16, 2022 23:58:50 GMT
I can't imagine having a window open when it's 9 or 10c outside like now. I find that having a wool duvet regulates body temperature so I don't get hot at night. One of the best purchases I've made in recent years actually, just so much better than a down duvet for me ...
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Post by petea on Nov 17, 2022 8:35:54 GMT
We bought a chopped silk filled ones as down and wool tend to get eaten by moth, etc larvae in the old house and they are very light and very warm.
Although the windows cannot be sealed properly, they are small and we also have traditional internal shutters and thick curtains so the house retains heat well and also stays cool in the summer. You do often need lights on even during the day though, but overall it is quite cheap to heat and we have insulated where possible: walls are solid, but thick and a small part of the front roof cannot be done, but the rest is.
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