Radiator Takes a long time to heat up

[koracer]

I've got a problem with a radiator taking a long time to heat up.

They system I've got is a open vented system. The radiator is the furthest one in the loop and is also the largest (Double Panel, 1.6m)
It's a new radiator but the one before was the same, it does eventually get hot. It takes probably 45 minutes to get hot all over and the return line seems to only ever get luke warm.

I've tried turning off all the other radiators in the house by the lockshild valve and it still doesn't get warmer any quicker.

I've opened the drain valve under the radiator and hot water comes down the return line very quickly and heats up the return line which I'd expect.

I've replaced the pipework and valves (none seemed to be blocked) to the radiator in the room but can't get to the main lines as they are under the floor.

I'm currently running sentinel x400 through the system to see if this will help once I drain it.

Any other suggestion as to what might cause this, all other radiators seem ok. Do I have blockage in the main feed or return pipe at one of the joins maybe? I really don't wnat to have to lift the floor boards up.

Am I just being impatient and the radiator will take this long and the return line not get hot?

Thanks

Keith

 

[delmel]

Could it poss need balancing, if hot water is running at same time this is likely to be taking president, or perhaps you have the pump low or a weak pump.

No expert but have come accross these as problems.

 

[swidders]

Could it poss need balancing

I've tried turning off all the other radiators in the house by the lockshild valve

It does now!