Constant bleeding of radiators required

Hello again folks!

Man I'll be glad when this boiler saga is all sorted, but I digress...

Ever since BG replaced the heat exchanger on 6th Jan (now 15 days ago), we have had constant cut-outs of the boiler due to the activation of the dry-heat stat in the Ideal Minimiser FF80 boiler.

The BG engineer said that this may be due to air in the pipe-work after the full drain-down.When re-filled, the c/htg had a small container of Fernox inhibitor added.

The pipework is probably (best guess) 25 years old as are most of the 14 double radiators on the system.

Whilst not "cold", the rads are noticeably colder at the bottom than at the top - an indication of sludge in the rads I think.

Every time the boiler cuts out and the dry-heat stat needs "resetting", I check the all of the rads and apart from the tall towel rail in the bathroom (with the highest vent in the house), the rads do not need venting.

Since the heat exchanger has been replaced, we have had a new boiler thermostat AND a dry-heat thermostat fitted.

So, my question is that due to the constant build-up of air (or gas) in this rad is this due to internal corrosion of the radiators on the system.

Incidentally, there is no sound of flowing water (eg bubbles) in the rads or pipework when the pump & heating are running, the pump hums quietly and the rads all heat up - so I find it hard to believe that it is trapped air in the pipework - so I am more inclined to believe that it is a build up of gas due to corrosion.

Do I need more inhibitor in the water or (more likely) a power-flush of the system?

One final question. Should BG have ensured that all of the radiators were properly bled of air or were they correct to leave this up to us? Opinions please.

Cheers,Dave

id get something decent fitted, if it wasn't on a repair contract i am willing to bet it would be in the skip already!

Any idea on the questions posted above?

Is it likely to be gas build-up due to corrosion or is it still air in the system?

Would more inhibitor help of do I need to flush the system first?

Dave

Go for the power flush mate, Inhibiter is as it says on the tin, it inhibits (or trys to) these problems further down the line.

Where in Yorkshire are you?

Dave, to get rid of the gas you have to get rid of the magnetite in the system.....lots can be got rid of by taking the rads off and flushing them in the garden with a hose, and running clean water through pipes to one rad at a time is about as much as you can do DIY wise.
At the same time, you can fit new valves to the system, with drain down cocks if you want - to help with any future flushing...maybe with a chemical.
John

Hi Hi gas_man_gaz,

Your profile says that you are in SHEFIELD. Are you Gas-Safe / Corgi registered and if so, would you be interested in quoting for a boiler replacement? Current boiler is a condensing Ideal Minimiser FF80. Mains water, gas & electricity all easily to hand. Boiler is in basement so re-piping or re-wiring would be quite easy - athough boiler is probably easy to swap - and vents directly through cavity wall to outside.

Tried to PM you but you need to be a friend!

I am resident in South Sheffield, nogoodatfaultfinding. Same questions as above.

Dave

sorry i dont do installs for anyone except family and friends. the company i work for (bg) would prob sack me for just having my own registration

Burnerman said:

Dave, to get rid of the gas you have to get rid of the magnetite in the system.....lots can be got rid of by taking the rads off and flushing them in the garden with a hose, and running clean water through pipes to one rad at a time is about as much as you can do DIY wise.
At the same time, you can fit new valves to the system, with drain down cocks if you want - to help with any future flushing...maybe with a chemical.
John

Click to expand...

Thanks John.

That's what I thought. Just had (15 days ago) a full drain down followed by a re-fill with small container (500ml ?) of Fernox inhibitor added.

Don't particularly want to go through that whole palaver of drain-down, remove each rad in turn, cart down to back garden & flush with a hose before replacing - IF the boiler (which is STILL giving problems) is on its way out as my 82 year -old mother is not in the best of health & feels the cold - so I don't want the heating off virtually all day.

Will have system power-flushed with new install to ensure all magnetite is removed.

As an interim measure, would a fitting a Magnaclean filter (yes another drain-down and re-fill) help if I constantly cleaned the filter? Fitting one is something that I could do myself.

How about running with x400 or x800? That would shift the magnetite - the latter in a few hours. Could afford to do a partial drain-down, add that, & then top up the system followed by a full drain-down & re-fill with inhibitor sometime later.

That way my mother would not be without heat.

Comments welcome. Cheers

Dave

You could try but your only gonna shift the crap around.

Do as you initially thought, get a power flush, add a magna clean and get a new boiler (Ideal have not made a good one since the classic).

Do you have any idea what boiler you want, Gas pipe size that is already there, do you need trv's, are you happy with thermostat etc or would this need sorting.

Full details will get you a near as damn it quote mate

Thanks
Charles

Yes Dave, if I was in this particular situation I would do exactly that - a good powerflush, followed by an addition of a Magnaclean....but I'd be inclined to have that done now rather than wait for the new install. Hopefully most of the grot would be dislodged during the flush and the Magnaclean would eventually take care of the rest, and the system would then be fairly clean for the new boiler.
John