26/10/2026
Every year without fail we have a customer call us up telling us the radiators in the loft are not getting hot, this year is no different.
Every year it’s pretty much the same issue, it’s a loft that we’ve built over the summer and the heating hasn’t been used, and now it’s getting colder customers start using the central again.
Occasionally it’s trapped air in the system which we have to attend to, nine times out of ten it’s simply user error.
A lot of people think that setting the trv valves to no.5, the radiators will get piping hot quicker, in fact it’s the complete opposite, all that does is allows the radiator to draw hot water for longer, the trv valve monitors the ambient room temperature not the radiator, the radiator can’t get any hotter than the temperature of the water coming out of the boiler.
Having all the radiators in the house set to 5 which quite often we find they are, is not only wasting energy as the boiler is using more gas and electric, but it’s also causing the water in the system to loose all its heat by the time it gets to the loft.
Simply by turning the trv valves down to 3 which still achieves 20 degrees room temperature, but it also allows the hot water in the system to flow further thus warming the radiators up evenly around the house including the loft.
