How do I put additive into my central heating system?

[jackthehat]

Hello folks,

Baxi Bahama combi boiler (aaarrrggghhh!!!)
The flow switches clog up every 6 months and British Gas is now refusing to repair it again unless we get the central heating system flushed out (£600). Obviously I am not going to pay that silly amount but the British Gas engineer kindly gave me a container of cleaning additive to add to the system. Apparently I need to add this and run the syetm as normal for a few weeks before flushing it out.

What I need to know is how do I add it to the system? Do I just pour it into the top of a radiator?

Once I've done that how exactly do I flush the system? The gas man said something about shutting all the radiators off leaving one fully open. He then said I had to open the overflow valve on the boiler and send clean mains water through the system. I had to do this for each and every radiator. He also mentioned something about an expansion tank in the boiler but I can't remember exactly what he said.

Can any of you whizz kids out there help me by filling in the gaps? Don't bother telling me to get a new boiler... I know it's crap but we can't afford a new one just yet.

Many thanks.

Jamie

 

[corgiman]

Before you cracked ahead you would do yourself some good by doing a quick search on Power Flushing, De sludging etc. There are a lot of pitfalls for the untrained in doing this them selves.

if you still couldnt give a **** then buy some Sentinell x400 injectable from your local merchant, POP to inject the instructions are on the tube.

 

[Nige F]

Gor Blimey , I fort you was dun for by the Krays, Jack

 

[corgiman]

Yar But he luvs his mother and you could walk the streets etc etc .....

 

[jackthehat]

So, er...thanks. So do I tip that stuff in top of a radiator or not? Is there a proper place where I add or inject it?

 

[corgiman]

just read the label on the stuff it tells you. no point typing it out here.

you inject it into the rad via the bleed valve

 

[jackthehat]

By the way, I have had a good search through previous posts about power flushing etc. Power flushing costs a lot and we have no cash at present. There's also lots of stuff about ripping off radiators and hosing them out etc. I would also like to avoid that if at all possible.

Our central heating loop still has the water main connected to it from when it was installed so we can easily pressurize the system and blast mains water through the radiators when required. I just need to know how to add the cleaning solution and then the proper procedure for flushing the system. Does anyone know what to do?

Jamie

 

[jackthehat]

Corgiman, I've read the label but there are no instructions telling me how to add it. The BG engineer mentioned something about adding it but I don't think he meant putting it into a radiator bleed valve. Would there be somewhere on the boiler where I can add it? Or would just putting it into a radiator do the job?

 

[Al-Glasgow]

I would close the two radiator valves on 1 rad.

drain some water from the rad from the drain point.

remove the large nut at the top opposite the bleed valve.

inject your chemical into the rad.

replace the nut, open the two valves, and bleed ait from rad.

allow system to run for appropriate time.

job done

Al

 

[jackthehat]

Thanks Al,

Sounds good BUT.. all our radiators are old things which have a bleed valve at the top and the standard two valve connection points at each end on the bottom. I don't think our radiators have drain points... or am I wrong? If I drain a small amount of water from our central heating loop via the main drain tap and then add the stuff through the air bleed valve on the highest radiator in the house would that do it? Obviously I would then need to repressurize the loop again before firing the central heating up.

 

[Al-Glasgow]

as long as you can isolate the rad then thats fine.

you could loosen the large nut between the radiator valve and the radiator itself to remove some water from it.

you might not have to top the system up as you might only have removed a litre or 2 of water.

Al

 

[JohnD]

I think you are going to have to learn to do a bit of plumbing...

If you really can't find a drain valve anywhere, the easiest way to fit one is with a radiator valve incorporating drain-off. However these are rather small and do not "gush" out the water, which is best when flushing. But it will be a start.

If you think you can manage compression joints put on a T and the biggest drain that will not spoil the look of your home. Preferably near the back door or sink where you can run a hose with the dirty water

I would hesitate to do this during the winter, if you cock it up you may be without heat until you, or someone else, can fix it.

 

[corgiman]

Must agree with john, have you tried getting so other quotes for the cleansing rather than do it yourself, sure you will find someone quite a bit cheaper

 

[jackthehat]

We haven't really got other quotes. I like to do things myself so I learn how to do it for next time. Our system does have a drain tap near the back door. I installed it myself a couple of years ago and have ran clear water through the system a few times before when p*ssing about with radiators etc. The BG engineer said it would be best when flushing to use the outlet valve on the boiler as the exit point. Do you know which valve I mean? It's the red plastic knob that you turn to release pressure from the system. I thought it would be best to use the drain point I installed as it is about 3 feet lower down in the system than the boiler valve.

So, to sum up.

1. Add the cleanser to a radiator using whatever method I can.

2. Run the system as normal for a week or 4.

3. Shut off all radiator valves but leave both valves on one radiator wide open.

4. Open drain cock near back door (or relief valve on boiler)

5. Turn on the mains water and blast it through the system for ages until water is running perfectly clear.

6. Shut off the radiator and do the same for all the other 14 radiators in the house.

7. Refill system and include suitable corrosion inhibitor.

8. Telephone British Gas and tell them to get their a*ses round and fix my boiler's crappy flow switches.

Does this sound about right to you fellas?

Jamie

 

[Nige F]

Our central heating loop still has the water main connected to it from when it was installed

Jamie

Well it should be disconnected when not in use due to the possibility of c/h water backflowing into drinking water .Is the container of inhibitor like a tube of mastic that goes in a gun if so it should have a small tube that you use to inject the fluid into the rad bleed hole If it`s not the BG guy has given you a bottle of cleaner that is usually poured into an expansion tank in a vented system.......Fitters.....They couldn`t fit a french letter (that`s a condom)..and Jack the hat Mc Vittie was murdered by Reg+ Ronnie in the "Blind Beggar" pub