Weather compensation vs fixed flow temperature
Weather compensation uses an outdoor sensor to lower the boiler's flow temperature on milder days and raise it on colder ones, matching output more closely to actual heat loss. A fixed flow temperature runs the boiler at one set point regardless of outside conditions, which is simpler but generally less efficient in the mild-weather months.
How we read weather compensation and fixed flow temperature on site
Running a condensing boiler at a lower, steadier flow temperature keeps it operating in its most efficient condensing range for more of the heating season, since fixed high flow temperatures push the boiler out of condensing mode on milder days. Weather compensation needs an outdoor sensor and compatible controls, and works best alongside radiators or emitters sized generously enough to still heat the room adequately at the lower flow temperature it selects.
Things worth knowing about weather compensation and fixed flow temperature
- Weather compensation keeps flow temperature in the condensing range more often
- Fixed flow temperature is simpler but less efficient on milder days
- An outdoor sensor and compatible controls are required for compensation
- Radiator sizing affects how well compensation performs in practice
- Compensation adjusts automatically rather than needing manual seasonal changes
Where we deal with this
Who should undertake the work
- Gas appliance work must be completed by a suitably qualified Gas Safe engineer
- Oil appliance work should be completed by a suitably qualified OFTEC technician
- Jamie Crawford Heating states both Gas Safe and OFTEC registration
Get weather compensation and fixed flow temperature looked at properly
The honest position: Compensation rewards a well-sized system with real efficiency gains; a fixed flow temperature remains a simpler, still valid, default.
Include the appliance make and model in your enquiry so the correct technical information can be checked.
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Services that cover this
Questions we get asked
- Is weather compensation worth retrofitting?
- It can improve efficiency on a compatible modern boiler, provided radiators are sized adequately for the lower flow temperatures used.
- Does compensation make rooms colder?
- Not if radiators are correctly sized; the flow temperature reduction is calculated to still meet the room's heat loss.
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