New radiator at end of system, not getting hot

MBerg

We recently had a small extension built, replaced one (largish) radiator with a medium and a small, these are the last two radiators on the system. Neither gets as hot as other radiators in the house. Boiler was fitted nearly 15 years ago, spec'd to be larger than necessary for the house to allow for an extension.
We always only needed to have the boiler setting on 1 - 2 to get radiators hot. Also, higher than that made the hot water unbearably hot.
Builder's plumber has been, couldn't find any problems. Then turned boiler setting up and all radiators went hot, so he says that's what we need to do. But, that means we waste money, and also the hot water is too hot to put hands into.

Any ideas?

andyhop

Sounds like the current rads need balancing correctly

Try turning the locksheild valves down on the radiators thats closest to the boiler

missile

You do not have seperate thermostat settings to cotrol your hot water and central heating?

MBerg

> You do not have seperate thermostat settings to cotrol your hot water and central heating?

How do you mean? - we have a Central Heating thermostat and a controller on the boiler, but with the boiler control on 1-2 the hot water temperature is fine, but last two radiators do not get very hot (even when Central Heating thermostat is high so heating comes on); with boiler control on 4 - radiators all get hot but hot water is too hot for hands!

M

diable

As mentioned previously they may need balancing but also check to see if any air is trapped in them by opening the bleed nipple.

sarge123

Recently done the same thing, and had the same problem.

It is definitely that your system needs balancing (ensure that you have bled your system all ready). Instructions can be found via the internet. They sounded a little fiddly to me so i got my plumber mate to do it for me.;)

derrick

MBerg wrote: »

> You do not have seperate thermostat settings to cotrol your hot water and central heating?

How do you mean? - we have a Central Heating thermostat and a controller on the boiler, but with the boiler control on 1-2 the hot water temperature is fine, but last two radiators do not get very hot (even when Central Heating thermostat is high so heating comes on); with boiler control on 4 - radiators all get hot but hot water is too hot for hands!

M

If you can put your hands under running hot water, then the water is not hot enough if hot water is stored. If not stored,i.e. combi then it is no wonder you cannot get the radiators hot enough, as the temp for heating should be between 70 & 80 C.
What sort of boiler? Combi or hot water storage, if storage it should be heated to 60 degrees Centigrade re Legionnaires disease