Upstair steel rads not heating, a little gas but no water when bled.
Downstairs cast iron rads working fine, along with 2 other steel rads.
Totally new system, with Worcester Bosch Greenstar Highflow 440.

Fernox inhibitor in system.

Has previously been a leak at lock shield on steel rad downstairs - nly occurred when system off.

How can upstairs cold rads be sorted?

Need some info so I don't get conned.

psaker, November 2006

Everyone is presuming you've checked that you have at least 1 bar of pressure showing at the boiler (little dial on the boiler, needle should be in the green area).

How hard does the water flow out of the top radiators when you bleed them? Is it a dribble or a full on shower? Dribble is bad by the way.

If it's only been 2 months then your installer should be able to help you under a warranty.

Toby, December 2006

Hello Thermgas

Whole system is completely new 2 months ago, including the steel and cast iron rads.

Presumably system was thoroughly flushed through by our plumber.

If Fernox is not doing its job at the moment, should system be flushed through again and a higher concenration added?

What else can be done?

psaker, December 2006

Fernox will help, but won't completely solve the issue unless it is in it's very early stages of gassing up.

Was the system flushed through properly before the new boiler was installed and has the system been balanced?


-> thermgas.co.uk

ThermGas, December 2006

Thanks for the suggestion Hi-Spec.

Tried it. First couple tof rads on upstairs circuit becam hot, then all rads upstairs faded to lukewarm at most.

Did bleed again; a little gas no water again.

Perhaps system needs re-filling after previous leak and gas build-up. Maybe pressure is down.

Our plumber thinks problems are likely to be all due to the cast iron rads and production of gas, even though Fernox should reduce or stop this, shouldn't it?

psaker, December 2006

sounds like air lock try shutting all downstairs rads to push water upstairs

hi-spec plumbing, December 2006