Rad leak - Topping up my central heating

[AndyJE]

Hi all.

I've searched this mine of information for about an hour, but couldn't quite find the information I'm looking for.

One of my downstairs radiator pipes leaked. Luckily I was at home at the time.

Quite a lot of water was let out. Whilst the water was still running out I stopped the leak by replacing the leaky elbow pipe. Going by the containers which were used to catch the leak, around 4-5 gallons leaked out.

What I don't know is how to refill the CH system. The instruction manual I have only mentions refill instructions for a sealed system.

The boiler is a Range Powermax 155x, which I believe is just over two years old.

Although it only says 155x on the cover panel, I believe it's an OV155xCP because it doesn't have a pressure gauge on the front of the unit, but it does have a digital programmer.
There are two cold water tanks in my loft, a biggun and a little'un.

So hopefully someone can help - does the system automatically refill itself and I just bleed the air from this rad, or do I need to refill manually?
Would I just use water, or some sort of water+inhibitor mix?

Thanks in advance
Andy

 

[JohnD]

if you have a small tank in your loft, say 1ft x 1ft x 18 inches, it is very likely the feed and expansion tank for your vented system (unless it has just been left up there and is no longer used)

it should have a ball cock/float valve in it like in a WC cistern.

BTW if you had tied up the ball, it would have stopped filling your system and the leak would have stopped.

You will probably find it is half full of water. there might be rusty brown mud at the bottom.

Bale out any brown mud anyway as you don't want it going down into your system.

It should have automatically filled the system to compensate for the leak. You may have air in the rads which you can bleed out as usual.

If you have a typical sized house, a litre of Sentinel 100 Inhibitor (about £15) will be enough. It is available at any DIY shed or plumbers merchant. You have to draw off enough water from a drain cock to draw the chemical down from the tank, after you have mixed it in. If you find a label saying it was filled with Fernox brand, use that one again.

If you got black water and sludge out of the leak, and there is brown sludge in the tank, this would be a good time to clean it out.

This is a separate question, but if you have a look at the first few threads in thes Plumbing Forum you will find it is already covered.

 

[AndyJE]

Thanks very much for the speedy reply, John.

I have indeed got a little tank like that. It's got a lid and is covered in a sort of insulated black bag material. It does have a ballcock.

So tying up the ballcock would have stopped the leak... Do you mean once all the water had drained out of the leak, or it would have stopped immediately?

I'll have a look in the loft tomorrow (it's past my bedtime now) and follow your instructions.

What is a typical size house? I have 6 radiators upstairs and 7 downstairs (counting the double size rads twice).

There is a label by the boiler which says Sentinel X100. The water coming from the leak was clean (although slightly yellowish) water. No brown sludge from the pipes, although a bit from the bottom of the rad when I took it outside.

Cheers
Andy

 

[JohnD]

if I count my doubles as two, I have 15, and one litre is correct for me.

if you had tied it up, you would have lost a gallon or two from the tank (they should be adjusted so they are only a couple of inches deep) plus the contents of the radiator, not much more.

your entire system probably holds less than 100 litres, most will be inside radiators which will not empty out through a single leak.

it doesn't sound like your system needs flushing.

 

[AndyJE]

That's really useful information, Ta.

I'll come back and reply in a day or two when I've put the rad back and filled it up, hopefully to thank you again!

Cheers
Andy