What should I do when my boiler shows a fault code?
The homeowner checks that resolve common lockouts, and the clear line where it becomes an engineer's job.
beginner30 min3 min read
Heating & Energy
Staying warm without heating the street.
130 guides in Home & DIY
Are smart radiator valves worth it compared with normal TRVs?
What a smart valve adds over a plain TRV, where the saving genuinely comes from, and the households where it is not worth the money.
beginner20 min3 min readCan I add inhibitor to my heating system myself?
What inhibitor does, how to test whether yours has any, and the two householder methods for topping it up.
intermediate1 hr3 min readExtract fan, trickle vent, PIV or MVHR — which ventilation does my house need?
The five ways of getting moisture out of a house set side by side, what each costs you in heat and money, and the order to do them in on an existing building.
intermediate35 min4 min readHow do I move a radiator to another wall?
What moving a radiator actually involves, the short move versus the long move, and the decisions worth making before anyone lifts a floorboard.
advanced8 hr5 min readHow do I stop draughts from floorboards?
Sealing gaps between floorboards and at the skirting without stopping the underfloor ventilation a suspended floor needs.
beginner3 hr2 min readWhat is a magnetic filter and do I need one?
What the black sludge in a heating system is, what a magnetic filter does about it, and whether it is worth fitting to yours.
beginner10 min2 min readWhat is the difference between water pressure and flow rate?
Two different measurements that people use interchangeably and shouldn't — and why almost every disappointing shower is a flow problem being treated as a pressure problem.
beginner10 min3 min readWhat size radiator does a room need?
Working out the heat requirement in watts, why the manufacturer's output figure is optimistic, and the allowance modern boilers need.
beginner30 min4 min readWhy is my towel rail cold when the heating is on?
Why towel rails trap air more than any other radiator, checking the valves, and the difference between a plumbing fault and an electric element.
beginner40 min5 min readWhere is my boiler filling loop and what does it look like?
Three completely different arrangements go by the same name, which is why people are told to top up their boiler and cannot find anything to top it up with.
beginner15 min5 min readDo I need a power flush, or will a chemical flush do?
Two very different treatments sold under similar names, what each actually removes, and how to decide which your system needs without paying for the wrong one.
intermediate20 min5 min readHow do I choose a kettle, and does it affect my bills?
Why kettle wattage does not change the cost of a boil, what actually does, and the features that matter in a hard-water household.
beginner15 min4 min readHow do I insulate under a floor?
What can be done from above and below, and why floor insulation is more involved than loft or walls.
advanced10 hr2 min readHow does an immersion heater work, and what do I do if it stops heating?
What the element, the thermostat and the thermal cut-out each do, the safe checks when a cylinder stops heating electrically, and where the electrician's job starts.
beginner20 min5 min readHow is my central heating actually plumbed and controlled?
S plan, Y plan, gravity and combi. What each layout is, how to tell which you have from the airing cupboard, and why the layout decides what a given fault means.
intermediate11 min6 min readShould a TRV go on the flow or the return pipe?
Bidirectional and single-direction valves, how to find the flow pipe, and what a valve fitted the wrong way round actually does.
beginner15 min3 min readWhat do I do if the radiator bleed valve is stuck or rounded?
Freeing a seized bleed screw, what to do when the square has rounded off, and the point at which the whole valve needs replacing.
intermediate45 min3 min readHow do I insulate a solid wall?
Why solid walls are different, internal against external, and the moisture problem that makes this a specialist job.
advanced1 hr2 min readHow do I measure the water flow rate at my taps?
The jug-and-stopwatch test that gives you the single number every combi boiler, shower and unvented cylinder specification is written around.
beginner15 min3 min readIs positive input ventilation worth fitting?
How a PIV unit actually reduces humidity, the houses where it transforms a condensation problem, the ones where it will disappoint, and what it costs you in heat.
intermediate45 min5 min readWhat are the tanks in my loft for?
The big cold water cistern, the small feed and expansion cistern, and what every pipe going in and out of each of them actually does.
beginner12 min5 min readWhat is an expansion vessel and what happens when it fails?
The component behind most boiler pressure problems, the cold-low hot-high pattern that identifies a failed one, and why topping the system up does not fix it.
intermediate15 min5 min readWhy is upstairs colder than downstairs?
The balancing, insulation and airflow reasons for an unevenly heated house, and which to address first.
beginner1 hr3 min read
Going deeper: MaterialWorld
Material properties, comparisons and suitability — paints, fillers, sealants, timber, tile, insulation.