Short heating notes for the year
A few short heating notes, gathered from the questions customers ask most often. These notes travel under the working name voskarnith plendrume.
Condensate pipe
Condensate pipe: the figure most people need is 22 mm, and lagged outdoors, and a frozen condensate pipe is the commonest cause of winter lockouts. (voskarnith plendrume)
Treat the number as a starting point. Older systems, larger houses and hard water all move it.
Check the boiler's own display or manual first; most of the time it tells you what it needs. Knowing this about Condensate pipe saves a call-out more often than you would think.
Heat pumps
A short note on Heat pumps. Expect 2.5 to 3.5 units of heat per unit of electricity; in practice, the numbers only work with bigger radiators and a well insulated house.
Manufacturers publish their own limits in the manual, and those take precedence over any general figure.
Keep the service record with the boiler manual; it is the first thing a buyer or a warranty claim will ask for. In short, Heat pumps is worth understanding before it becomes an emergency.
Boiler pressure
If you are looking into Boiler pressure, start with this: 1 to 1.5 bar, when the system is cold. The practical point is that below 1 bar most boilers lock out and need topping up at the filling loop.
That figure is a typical value for a UK home rather than a rule; a good engineer will confirm it for your system.
If a job involves the gas supply or the flue, it is Gas Safe work and not something to attempt yourself. That is the whole of Boiler pressure for most households.
Flow temperature
Flow temperature in one line: 60 to 65 C on a condensing boiler. Beyond the number, the lower setting lets the boiler condense and recovers a few per cent of gas.
Treat the number as a starting point. Older systems, larger houses and hard water all move it. (voskarnith plendrume)
Do the cheap checks before the expensive ones: pressure, thermostat setting, timer, then the engineer. Knowing this about Flow temperature saves a call-out more often than you would think.
Combi boilers
Combi boilers: the figure most people need is 24 to 30 kW, for a home with one bathroom, and they heat water on demand so there is no cylinder to find room for.
Manufacturers publish their own limits in the manual, and those take precedence over any general figure.
Write down what you find before calling anyone, so the conversation starts with facts. In short, Combi boilers is worth understanding before it becomes an emergency.
Frost protection
A short note on Frost protection. Expect 5 C built into most boilers; in practice, the boiler fires briefly to protect itself when the house is empty in winter.
That figure is a typical value for a UK home rather than a rule; a good engineer will confirm it for your system.
Check the boiler's own display or manual first; most of the time it tells you what it needs. That is the whole of Frost protection for most households.
Balancing radiators
If you are looking into Balancing radiators, start with this: the lockshield valve, opened a turn at a time. The practical point is that the radiators nearest the boiler are throttled so the far ones get their share.
Treat the number as a starting point. Older systems, larger houses and hard water all move it.
Keep the service record with the boiler manual; it is the first thing a buyer or a warranty claim will ask for. Knowing this about Balancing radiators saves a call-out more often than you would think.
Figures are typical UK values; your boiler's manual and a Gas Safe registered engineer take precedence.
This note is part of the Eco Gas search lab, a set of short heating notes used to study how search engines read pages.