I have spent this month reading energy bills. Not our own, though those are on the desk too, but the bills of the households who wrote in after Issue 2. The pattern is clear enough that I want to write about it plainly.
Almost every household that thought it had a heating problem turned out to have a control problem. The boiler was fine. The radiators were mostly balanced. The thermostat was in a hallway that ran cold because of a front door with no draught seal, and the household was compensating by turning it up two degrees and then wondering why the bill had climbed by three hundred pounds a year.
I am wary of anything in the home industry that sounds like a hack. There is a real answer here though, and it is about where you measure the temperature, not what you set it to. If the thermostat sits in the coldest room in the house, the whole house is heated to the comfort of the coldest room. That is a lot of gas.
We have also written about the standing charge for the first time. I did not want to. It reads as inside baseball, and there is a temptation in this kind of publication to stick to warm, sensible advice about jumpers and hot water bottles. But the standing charge is now the single most consequential number in a UK energy bill for a low-user household, and pretending otherwise would be dishonest. If it costs you a pound and thirty pence to keep the meter connected each day, that is very nearly five hundred pounds a year before you have used a single unit. That has changed the calculus for everyone from student households to widowers living alone, and we are going to keep writing about it.
Finally, a reminder that a warm home is a health matter. The evidence from the UK Health Security Agency is unambiguous. Cold homes cause hospital admissions, particularly in the over-sixties. If you know someone whose bill anxiety is stopping them heating their bedroom, this issue is for them, and the free things at the front do more than the expensive things at the back.
The next four weeks bring the coldest sustained conditions of the year. Overnight temperatures below zero are likely in the second half of the period, and daylight hours are at their shortest. Any household running heating on a fixed schedule, without weather compensation, will notice the boiler working harder than it needs to.
- Comfort risks
- Cold external walls, particularly on the north and east sides of a house, drop several degrees below the room's air temperature during a cold spell. That is why a room can feel cold even when the thermometer reads 20; the wall itself is pulling heat out of the body by radiation.
- Ventilation
- Do not close every vent to save heat. A tightly-sealed room in winter is a condensation problem waiting to happen. Trickle vents are cheap to run and expensive to compensate for.
- Overheating risk
- None.
- Condensation risk
- High. Any household that dries laundry indoors, cooks with lids off, or forgets to run the bathroom fan will find visible condensation on windows every morning.
- Pollen
- Not a factor.
- Humidity
- Indoor humidity falls quickly when the heating runs hard, which is why skin and airways get dry. A humidity of around 45 percent is the working range; a small bowl of water on a radiator is a surprisingly effective way to nudge a dry room upwards.
- Maintenance cues
- Check the pipe outside where the boiler condensate drains. In a hard freeze it can block, and the boiler will lock out. Lag it now with pipe insulation from any hardware shop.
If you only do one thing this month, put a small thermometer in the room where the thermostat lives, and another in your coldest room, and compare them at eight in the evening.
This month at home
A comfortable UK winter is not a matter of turning the thermostat up. It is a matter of getting the heat you have paid for to the rooms you actually use.
Almost every UK home has one radiator that runs cold and another that runs too hot. The household compensates for the cold one by raising the whole-house thermostat, which overheats the rest of the house, which the household then compensates for by opening a window in the bedroom. It is a system in which nearly everybody is uncomfortable and the boiler is burning gas the entire time.
The fix is called balancing, and any plumber will do it in a morning. If you can find your radiator lockshield valves, hidden under a plastic cap on the opposite end of the radiator from the temperature knob, you can do it yourself with a screwdriver and a thermometer. It is one of the highest-value hours of work in a UK home, and it is genuinely free if you do it yourself.
The other habit worth building this month is closing curtains at dusk. A single-glazed window loses about ten times as much heat as the wall around it. A lined curtain across it changes the picture, but only if it is drawn before the room gives up its heat, not after.
Free things you can do this week
- Close curtains at dusk, not at bedtime. The heat you save is the heat that would otherwise be radiated out of the room in the two hours after the sun sets.
- Move furniture off any radiator that is blocked. A sofa in front of a rad is heating its own back. Leave a fifteen-centimetre gap.
- Turn the thermostat down by one degree, and note whether anyone in the household actually notices. In most homes, nobody does; the change is worth about ten percent of the annual bill.
- Bleed every radiator that is cold at the top. If bleeding does not fix it, the system may need balancing.
- Lag the condensate pipe outside the boiler with foam pipe insulation. A ten-minute job that prevents the boiler locking out on the coldest morning of the year.
Low-cost improvements worth making now
A thermostatic radiator valve on every radiator in a bedroom or a spare room, or in an unused office, lets those rooms sit two or three degrees below the main living space. That is the single lowest-cost way to bring bedroom bills down without any impact on comfort in the rooms that are actually used.
A radiator reflector panel behind any radiator on an external wall costs a few pounds a metre and reduces the heat lost through the wall behind it. The physics is modest but real; on a solid-brick wall with no cavity insulation the difference is measurable.
Understanding your home ; the standing charge
A standing charge is a daily fee you pay to be connected to the gas and electricity network, regardless of how much energy you use. It covers the cost of the poles, wires, meters and the transporter that owns them, plus a share of the cost of supplier failures. Ofgem sets a cap on it, and the current cap for a typical household is around 33 pence a day for gas and 62 pence a day for electricity, with regional variation.
That number matters more the less energy you use, because it is fixed. A household that uses very little energy still pays roughly £350 a year in standing charges. For a household that has invested in insulation, solar panels and a heat pump, the standing charge can be a bigger part of the bill than the actual energy used.
There are tariffs that raise the unit price of energy in exchange for a lower standing charge. They suit different households; a small flat with low usage benefits, a large family home usually does not. If a household is thinking of removing its gas supply entirely, the daily gas standing charge is often the deciding number.
Take this further
Grants and money
The Warm Home Discount opens for eligible households, currently a £150 rebate credited to the electricity bill. Eligibility is means-tested and the deadline for automatic inclusion is early March.
The Boiler Upgrade Scheme remains at £7,500. Note that most heat-pump installations booked in January and February are pipeline from October surveys, so if a spring installation is the goal, the survey needs to happen this month, not next.
In Scotland, Home Energy Scotland grants and interest-free loans continue. The current combined offer is materially more generous than the English scheme.
Take this further
Myth of this month
Leaving the heating on low all day is cheaper than turning it on and off.
This is one of the most enduring beliefs in the UK, and it is, for almost every household, wrong. A well-insulated home benefits from a slower warm-up and a longer window of comfort; a poorly-insulated home loses heat as fast as the boiler can supply it, whether the thermostat is set to 18 or 21. In both cases, the household pays for less gas when the heating runs only when people are at home and awake.
The exception is a household with a heat pump. A heat pump runs most efficiently at a low and steady flow temperature; turning it off for eight hours and back on demands a lot of it during recovery. If the household has a heat pump, keeping the temperature within a narrow band, day and night, is genuinely cheaper.
My hallway is always cold and the thermostat is in the hallway. Should I move the thermostat, or is that a bad idea?
From a Reader in Sheffield.
This is the single most common question we receive from households with a combi boiler and a wired thermostat, and the honest answer is yes, moving it will almost certainly reduce your bill. But it needs to be moved to the right place.
The thermostat should sit in the room where the household actually spends most of its evening time, at head height, away from radiators and sunlight and away from external doors. In most homes that is the living room, on an internal wall, roughly a metre and a half from the floor. When the thermostat lives there instead of in the hallway, the whole system heats the house to the comfort of the room that matters, not the room that runs coldest.
One practical caveat. If the hallway is cold enough to be uncomfortable, that is a signal that something is wrong upstream. A front door with no draught seal, a letterbox with no brush, or a suspended timber ground floor with no insulation below it. Moving the thermostat is the right answer for the bill; fixing the cold hallway is the right answer for the house.
- Energy Saving Trust, Heating and hot water guidance
- Ofgem, price cap and standing charge information
- UK Health Security Agency, Cold Weather Plan
- MHCLG, English Housing Survey
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