Heat Not Radiating

[RoofRat]

Hi guys,
Just joined here looking for tips and tricks and also to pass on any roofing knowledge required.

Anyway, having a small problem with my heating.
House is about 6 years old, and I moved in about 20 months ago.
Normal weather and the heating works fine and heats the house.
But recently in these sub zero temperatures the house just isn't heating.
The radiators are hot, but not untouchable, all have been bled, and thermostat is up full.
Still feels chilly.
Boiler was serviced about 4 months ago with no problems.
Pump seems to be working an dis hot to the touch as well.

Any idea what could be the problem ?
A friend who stays in a similar house says that if his heating is up full his radiators are virtually untouchable, but mine are not like that.
Thanks for any help.

 

[xr4x4]

rad remps are normally controlled by the boiler stat.

whe does the heating come on?

it will take most of the day for a old house to heat up comfortably.

 

[RoofRat]

Heating comes on about 5pm, and I get home about 6.30
It's virtually a new house mate, so should and does heat up quickly normally.

 

[xr4x4]

even so, an hour and a half is not alot of time to heat a house in these unusually low temps.

you could try and turn the boiler stat up a bit, but its really a good idea to have red hot rads.

try leaving the heating on low all day while your out and boost it when you get home.

see if that makes a difference.

 

[D_Hailsham]

House is about 6 years old, and I moved in about 20 months ago.
Normal weather and the heating works fine and heats the house.
But recently in these sub zero temperatures the house just isn't heating.
The radiators are hot, but not untouchable, all have been bled, and thermostat is up full.
Still feels chilly.

The heating system has probably been designed to provide a comfortable temperature (21C) when it is -1C outside. If the outside temperature is lower, say -11C, the inside will drop by the same amount, from 21C to 11C. You may get better than this as most systems are oversized by 10-20% to provide faster warm up times. But there comes a limit when the heat given out by the radiators is equal to the heat lost through the walls, so the house will not get any warmer.

Depending on your boiler, you may have spare capacity to install larger radiators.

Use the Stelrad Elite Catalogue to calculate the total output of your rads (all manufacturers are very similar) and compare it to the quoted output of your boiler.

 

[RoofRat]

even so, an hour and a half is not alot of time to heat a house in these unusually low temps.

you could try and turn the boiler stat up a bit, but its really a good idea to have red hot rads.

try leaving the heating on low all day while your out and boost it when you get home.

see if that makes a difference.

I went to my bed at 1am this morning, and the heating had been on at full since 5pm last night and it still hadn't heated the house as much as it does usually.
Thanks for the comments, and I will check and try as suggested before trying to get someone out to check it.