Cleaning sealed system

[GETDADIN]

Ok - I have a Radiant Slim combi-boiler, fitted 1999. It has had services etc but it seems to be one of those appliances that as soon as one thing goes wrong, its closly followed by two more!

Anyway, we recently did some work in a room and had to remove a radiator. When the rad was put back on all was fine. a few weeks later the boiler completely drained itself overnight via the overflow outlet in the wall. Plumber called - problem fixed - dirt on something! 2 weeks later no hot water - plumber called flow valve fixed. 1 day later cold water again - plumber called, thermostat changed.

Bill from plumber arrived with a cover letter to advise that they noticed that the system would benefit from a chemical clean, at £500! We figured that we should be able to use that Sentinal 100 and/or 500 and do it ourselves, but how do you get the liquid into a radiator in a sealed system?? Someone suggested using the fill loop near the boiler, but cant see how to do it.

Also another quick point, since putting back the removed radiator, another radiator in another room has started clicking when the heating system starts up - it is extremely annoying at 4am and has now interupted many nights sleep. We have Drayton thermo valves on all rads, and I have just read that it might be worth changing that one, but any other ideas?

Never had any problems with the 2 seperate boilers pre 99 that were used for over 11 years!!

 

[breezer]

i am not a plumber or heating engineer, i know most things by reading these forums, you can put the sentinel in via the rad bleed valve, i have read it somewhere on here thats how its done, not the filling loop as that would mean it would have to be under pressure

 

[GETDADIN]

Thanks, but how exactly?

I would, I imagine, have to drain down some of the system as the boiler will only function at 1 (is it bar?) pressure, and actually runs at 1.5, so if I drain down some of the boiler and go to the radiator upstairs (there is only 1 we live in bungalow!), unscrew the bleed valve, do I just simply stick in a tube attach a funnel and pour?

Thanks for your help.

 

[oilman]

Breezer, it's possible to put stuff in using the filling loop, you just need a different adaptor. You need to reduce the pressure whichever way you do it, so it's no problem. If you have to put leak sealer in, it can cet stuck in the radiator bleed valve, so the filling loop is easier.

 

[boilerbeasty]

I've used Fernox in my sealed system. You can apply it with a mastic gun via the radiator bleed valve. Basically you wait for the system to be cold, isolate a radiator and open the bleed valve. A bit of water comes out. You remove the valve completely and open the return pipe. Then squirt all the cleaner in through the mastic gun, replace the valve and open both valves. It comes as a plastic tube for a mastic gun, along with a plastic tub and a screw in adapter for the radiator valve.
Took me about 10 minutes to do.

 

[GETDADIN]

Thanks guys! Off to the plumber supply shop to check out options. If I use the fernox however, do I simply leave that to run round forever, or at some point do I have to flush through? (sorry to sound so dumb can I use the excuse of blonde and female???) Normally get the Dad in hence the log in name, but he has no experience of sealed systems either.

I really appreciate your help

 

[taydo]

if you want to clean the system you will need to drain it down as per info on the can

then re dose with inhibitor

Brian

 

[ChrisR]

If the system has been building up corrosion debris for years then you will not get it clean now simply by circulating a chemical and draining it out. The £500 job will be a "power flush" which removes far more.

We know nothing of the state of your system. Just because a bit of something made that pressure relief valve leak (common) it doesn't mean you have a seriously dirty system - but you might have. Are any radiators working less well than they should, for instance?

Neither Sentinel X100 or X500 is a cleaner!

You shouldn't be surprised by odd problems with a 5 year old combi, I'm afraid. The previous 2 lasted only 11 years...!

Sludge doesn't cause ticking rads. Try operating the rad withthe thermo head removed to diagnose.

 

[GETDADIN]

I am amazed by these fab responses - sooo helpful Thank you all.

The previous boilers were ancient and ran for us for 11 years no problems, but could well have been working many many years previously.

Is £500 reasonable for a "powerflush", and is that what the plumber co refers to as a chemical clean?

My rads all seem to be working fine, no under performers anyway - one rad (the one removed and replaced recently) is over hot, I did turn down the water flow to barely on, and it still blasts out heat, even with thermo valve on low.

We do live in a very hard water area, and I think could be limescale in system....

I have changed the thermo valve last night with one from another room, and still it tick tick ticked this morning - will try no valve tonight. If its not that though what else could it be?

Thanks again

 

[ChrisR]

"£500 for a powerflush" BG sets the silly prices - the rest of us only have to undercut them to get rich. NOT the same as puttng a chemical in and emptying out though, it should take a day. BUt you don;t seem to have the symptoms to need it. Limescale from your tap water doesn't get into your radiator water .

Ticking can be caused by pipes pressing against the woodwork. When they warm and expand they move. If you have fitted carpets an'all, you can try wd40 with its little hose to get some lubrication down the hole where the pipe disappears. Or, get hold of the radiator in a manly sort of way and heave it lengthwise a bit. If that doesn't work try the other direction, in a womanly sort of way.

 

[GETDADIN]

Thanks Chris

I took your advice and removed the TRV and when heating started up today went in to the room and had a listen, and within 5 mins there is the tick tick ticking again - so not the TRV. I hear what you say about the pipes expanding and rubbing against the floor boards, but the noise actually comes from the rad, not the pipes. I have tried the manly (in a womanly fashion) shoving of the rad, it didn't do anything, hitting and throwing things at it doesn't either. Someone did say it might have been the brackets expanding against the rad, so we did try the WD40 (or gt85 as used in our house!), and it did nothing, other than create a workshop spell in my bedroom!

We never had this noise until we removed a rad in another room!

It is the people who fitted our system that want to charge the £500 for chemical clean. They recently had to change some thermo thing (looked like it belonged on a submarine not in a boiler), as they said it would be too difficult to clean, it seemed to be discoloured on the inside with reddish powder stuff, but couldn't really see anything else - just took word for it and paid £190!!

Any way I need to get them back out again as I have just noticed there is water dripping out of the pressure release pipe again - only replaced a few weeks ago.

Damn boiler!!

 

[ChrisR]

Well at least your bedroom smells nice.
Could try lifting the bloody thing then - it might settle a bit differently on its hooks.
Not too hot on submarines. ...

This dripping though - the pressure relief valve will only let water out if the pressure gets above 3 bar. If it hasn't done that (which would have indicated something wrong elsewhere) then yer man must have left it leaking. If it had got to 3 bar the "elsewhere" should have been put right last time.

 

[GETDADIN]

Chris shame you are in Antarctica otherwise I would get you round!!

I think you may be right about leaving it leaking - I honestly can't say I have paid it much attention since he fixed it (made mental note to check in future!)

However, this did happen previously and they told me that the filling loop must have been left open, so I did check this, and it is definately shut, but I did turn it open to make sure all ok, and actually could not feel or hear any water filling. Was going to drain a bit down and see if I could then fill up, but Hubby told me to leave it for those that know ("If they broke it they can fix it!").

I am sure I would make someone a great husband!

Oh! and done the lifting thing too - any other ideas (short of getting new rad - can't afford it with my bi-weekly heating technician (plumber) visits!

I previously meant sential x400 (I think) not 500......

 

[oilman]

Note about filling loop.

This should be disconnected when not in use to prevent possibility of contamination of water supply and to prevent leaking of system if the filling loop tap leaks (and worse if the safety valve doesn't open).

 

[GETDADIN]

Thanks Oilman - Something else to worry about.......