3 years of air in sealed system and now a leak

[Ltnman]

History:

In April 2008 I had a Worcester 42CD combi boiler fitted. Up until that date I never had to bleed the radiators. Despite double dosing the system with Furnox and placing a nail against the magnaclean magnet to confirm that no corrosion was present I have had to bleed 3 radiators once or twice a year. Despite bleeding the rads I did not have to re-pressurise the boiler.

In August this year I had a new bathroom fitted with the old radiator replaced with a towel rail that was moved to an adjoining wall. Again the rads had to be bled a couple of times over the next few weeks but this time water had to be added to increase the pressure. I put this down to the fact that a rad had been moved and replaced.

Around three weeks ago I noticed that the pressure was almost zero so while I was in the mood I shut the magnaclean off and cleaned the magnet. I then forgot to open the valves either side of the magnaclean. The boiler would fire up for a few seconds and then cut out. Not realizing that I had forgotten to open the valves I tried turning the key to add water but nothing happened and so could not increase the pressure. I then remembered to open the valves and could re-pressurise the system and the boiler came to life.

Since then I have had a new kitchen fitted but the rads were not touched although the main incoming cold feed to the boiler had to be re-routed to allow kitchen units to be fitted.

I am now loosing half a bar every couple of days. No sign of leaks as I have gone to every radiator with a tissue and checked the lockshieds, bleed nipples and every exposed joint.

Question, where did this air come from since the combi was installed?
Is it likely that the company that moved the rad has caused a hidden leak?
By me forgetting to open the valves have I cause a leak inside the boiler as I now have an escalating problem that has got worse this week but with not a sign of any leak or leak marks on the walls and ceilings.

 

[mr-crs]

Hi first question are you sure it was air and not Hydrogen in your rads ? did you try lighting it as it left the bleed nipple?
second question in the realm of anythings possible its possible that they caused a leak. third question your boiler has an auto bypass installed internally so shouldn't have caused a leak. you can check your boiler by turning off the flow and return isolators at night then checking them in the morning or in the morning if your house is empty but make sure you put the boiler in summer mode so the heating doesent come on.hope this helps Paul.

 

[Ltnman]

Thanks Paul for the reply. First I have heard about Hydrogen so no I have not tested for it but will in the future. The Rad water is clear and the magnaclean picks up almost no sludge each year.

When you say the flow and return isolators are you talking about the valves either side of the magnaclean which sit in between one 22mm pipe in the former airing cupboard?

 

[mr-crs]

No the isolators under the boiler( the 2 outer ones) this will isolate the boiler from the pipe work and if it still drops then the boilers at fault if not im afraid its on the pipe work somewhere, hope this helps Paul.

 

[Ltnman]

I took the bottom cover off the boiler and water poured out so hopfully I have a boiler fault and no other leaks.

Thanks Paul for your advice. I will keep you informed.

 

[Ltnman]

The boiler leak was the condensate leaking where the pipe joined the boiler.

OK so I am back to square one with it looking like I have a pipe / rad leak.

I will isolate the boiler by shutting down the isolation valves on the boiler and will check the pressure after a couple of days. Should I also shut off all the radiators so I am testing just the pipe work or leave the lockshields on either side of the radiators open?

Just need a couple of mild days to do this as it takes 48 hours to see a half bar reduction in the pressure.