Radiator cold at bottom, hot at top - Valiant Turbomax

[Cowboy10]

My system is a Valiant TurboMax 824E.

My front room radiator, which i'm told is the last in the chain, gets hot at the top, but not at the bottom.

The "In" pipe going into the radiator is hot, but the "out" pipe going back to the boiler is cold/lukewarm.

Google searches pointed me towards a sludge problem, so I removed the rad & flushed it out, but there was nothing. All rads were balanced correcly a few months ago when i had the boiler serviced.

All boilers have been bled, so there's no air in the rads, & the Boiler prssure is 1.5, as the manual suggests.

Could there be a problem with the outlet valve? Any other ideas that you may think of?

I'm told also that the Boiler is kicking in too much - possible due to the outlet pipe water not being hot enough?

Not sure if it's linked, but sometimes if the upstairs rads are on the last in the chain (front room) does not warm up as much.

However, tested this morning with ONLY the front room radiator on, & same problem.

Thanks in advance for your answers - I'd like to get the front room warm for xmas, when we have guests!

Lee

 

[xr4x4]

what if you turn a rad off..

pump speed?

 

[Cowboy10]

what if you turn a rad off..

pump speed?

Just pulled the front off the boilr & looked at the pump itself. There's a switch setting on the top or 1 & 2, It's set to 1. Not sure what the setting is, it's not in the manual.

In the middle of the pump, there's a slot to fit a screwdriver, but there's no display to show what pressure it's currently pumping out at - I'm a bit dubious turning it up, in case it's too high.

Just seems to me like it's either the rad, the outlet valve, or worse, something between the outlet valve & the pipe back to the boiler.

 

[xr4x4]

slot in pump is for bleeding, 1 speed is the lowest.

unless its a small system, speed two is normal. maybe a little more noisy tho.