Re: Radiators and CH system...

[Christian McArdle]

The system now appears to be working OK, but I have some questions:

> First, have I omitted anything or is the system good to go? > There was a certain amount (but not much) of black sludge, and the > Collins book suggests using an anti-corrosion aid in the water - how > can I get that into a pressurised system? Is it necessary?

It is absolutely essential to install corrosion inhibitor. On a pressurised system, there are a number of solutions to getting the stuff into the system. It is possible to get it concentrated into a syringe that you insert into the bleed valve on a suitable radiator.

My preferred technique is to add an additive point when the system is drained down. This consists of a T piece with a short length of pipe sticking vertically upwards terminated by an isolation valve and another short length of pipe. You can then stick a funnel in and pour what you like before refilling. Just remember to turn the valve off before starting the filling loop up! Using this method you can use standard inhibitor which is much cheaper than proprietary injection systems.

Further, I guess this will be at (or level with) the lowest point in >the system. I can't find it anywhere on the lower floor, though - >any suggestions as to where I could find it?

There might not be one. Install one yourself if you get the chance.

Christian.

[Andy Hall]

As long as the radiators are filled and the system is maintaining pressure then you should be OK.

Absolutely. It is the best £20 insurance policy you can buy. The black sludge is corrosion of the radiators, which left unchecked will lead to their demise. In extreme cases this can be a small number of years.

Before you add inhibitor, you may feel it appropriate to drain the system and clean all the radiators. I've made some previous posts on how to do that and flush at each radiator.

You could also use a chemical flushing agent, but this will not remove significant sludge. If the system is running OK, you could just do that.

For sealed systems, Fernox and others make gel compounds (there's a cleaner and an inhibitor) that can be injected into a radiator using a tube (provided) and a mastic gun.

However, I do not recommend the maker's instructions on this which is to inject with water in the radiator and against the pressure. It can be messy. I found that a better way is to drain a radiator as you did and squirt the stuff in before refilling.

.andy

To email, substitute .nospam with .gl

[Ed Sirett]

Load of info in the SealedCH faq. The thermo valve should really have been able to shut off and the lock-sheild.

Which side of the valves did you loosen to remove dthe rad?

Did you add inhibitor on refilling.

[Adam]

-88-

Thanks for the advice, Christian. I'm going to be removing another radiator fairly soon - I assume it will be OK to wait until then?

I think I'll leave pipe work for the moment and go with other suggestions, such as squeezing gel into a radiator, for now.

-88-

It doesn't look like there is. Again, I'll leave this for the moment...

Cheers - Adam...

[Adam]

-88-

Indeed, and I've read it a couple of times now.

That's what I though (thermostat should have closed). Next time I'll try the frost (*) setting rather than 0.

I first loosened the nut between the radiator and the lockshield (having closed the lockshield). By the time I got to the nut between the radiator and the thermostat, the system was empty.

No (as discussed in previous posts), but I'll do it once I'm onto the next radiator that needs to be removed.

Thanks for the help - Adam...