AEL - Opera aluminium radiators

[mf13]

I have just had a new central heating system installed with the above radiators. The water connections are at the top and bottom of the radiators with a thermostat valve at the top connection. The radiators do not get very warm at the bottom (there is certainly more than a 10 degree difference from the top) but the installer tells me this is normal for this type of aluminium radiator. Can anyone confirm this please?
Also at which point should the water enter the radiator - top or bottom?
Would be very grateful for any answers

 

[doitmyself]

The radiators do not get very warm at the bottom (there is certainly more than a 10 degree difference from the top) but the installer tells me this is normal for this type of aluminium radiator. Can anyone confirm this please?

The temperature difference is nothing to do with the type of radiator. It's all down to the boiler. Some boilers work with an 11°C differential; others with a higher, usually 20°C differential. Which make and model boiler do you have?

Also at which point should the water enter the radiator - top or bottom?

It should enter at the top and the TRV should, preferably, be here with the control horizontal.

 

[mf13]

Thanks for your reply. The system is powered by a pellet boiler/stove which heats the circulating water to a selected temperature between 60 and 80 degrees C. I've currently set it to 70.

The thermostat is connected at the top and is horizontal but I've noticed that the pipe connected to the bottom of the radiator gets hot marginally before the pipe connected to the top, when the system starts pumping hot water. After that the top of the radiator heats up but the bottom remains relatively cool. Could it be possible that the send and return from the pellet boiler are connected the wrong way round?

 

[doitmyself]

I know nothing about pellet boilers.

Don't you have the boiler instructions showing which is the flow connection and which the return?

Presumably you have one radiator without a TRV to act as a heat sink while the boiler cools down.

I presume it is not a one-pipe system and you have balanced it.

 

[Plouasne]

I know nothing about pellet boilers.

Don't you have the boiler instructions showing which is the flow connection and which the return?

Presumably you have one radiator without a TRV to act as a heat sink while the boiler cools down.

I presume it is not a one-pipe system and you have balanced it.

A wood pellet boiler is more like a gas or oil boiler, there is very little residual heat in the boiler, when the water in the boiler is up to the required heat, so no need for a heat leak like in a conventional solid fuel boiler

 

[Jimbob]

ah iv seen pellet boilers. i presume it has a massive buffer tank? alot do. I would of though aluminium rads would have a greater differential compared to a steel rad at the same flowrate through the rad. Maybe the flow needs to be increased through the rad when balancing?

 

[doitmyself]

A wood pellet boiler is more like a gas or oil boiler, there is very little residual heat in the boiler, when the water in the boiler is up to the required heat, so no need for a heat leak like in a conventional solid fuel boiler

You learn something every day.