Do I need a Powerflush and/or new radiators?

NotADiyGuy

Hi everyone

I have a question about my central heating system. I think it might need a powerflush and corrosion inhibitor treatment but I'm concerned that our radiators may need replacing and would like some advice on whether that is needed.

We have sixteen radiators. Last winter three of our rads developed tiny holes and leaked and over the past few years some of the o-rings have gone on the values. When emptying these radiators the water was like black ink.

The system is about eight years old. I'm not sure if it was ever flushed correctly and treated with corrosion inhibitor - there is no record of it. One thing I've noticed on a few of the rads is there is orangey/brown rust around the bleed value - some of the bottom connectors have the rust and some a greenish oxidised type colour sludge build up.

We've had a problem with the system gradually losing pressure over time. After the most recent radiator problems it seems that failing o-rings were causing some of problem. We are still losing pressure but very slowly now but nonetheless it is still dropping over time. I suspect changing all the o-rings and checking all connections might be a good idea here given that so many have failed. There was no visible leaks from the values when I last checked but yet the pressure still drops over time.

I also suspect the system is not balanced correctly because other radiators warm up faster than others. Some of the radiators have cold spots at the bottom - consistent with what I've read about sludge build-up.

I need to buy two new radiators to replace the faulty ones before the winter and I suspect that I probably need to get the system power flushed/corrosion inhibitor added but I suppose my concern is am I sitting on a time bomb of all the radiators going? Do I seriously need to contemplate replacing all the radiators or will a power flush etc be ok? I need to resolve the pressure dropping problem and get the system balanced correctly also.

Do I need a domestic heating engineer rather than a gas safe "Gas Boiler (Central Heating DOM NG)" type person?

Many thanks

ziggyman99

If your system is pressurised and only 8 yrs old, I suggest there was no inhibitor added if this amount of damage has occurred in such a short timescale.
Your radiator may be OK but seeing as several have punched through with corrosion already it doesn't bode well. I would advise changing anything with obvious signs of leaking. Once that is done give it a powerflush and see what gives. You may find a few valves letting go when powerflushing. They are often held together with dirt! Been there, got the T-shirt!
Your not going to be able to make a judgement on whether the system is balanced until the system is clean. Dirt will unbalance a system. The pressure drop problem should be sorted once all those leaking valves are changed. Sometimes it's impossible to find the source of a slow pressure drop in which case a leak sealer can be added.
You don't need a Gas safe engineer per se but I would hope that most domestic heating engineers would be registered. Of course they could be HETAS or OFTEC instead. What you need most of all is someone who can work out your problems and sort them out for you at an honest price.
I'm not sure where you are but you could try www.checkatrade.com. I'm on there so it could be me! :cool: