Leaking Filling loop on Combi Boiler

[Alex Boothby]

Hi All,

First of all thanks to everyone who helped with my previous questions.

Boiler:
Ideal Mini c28

In short! My boiler pressure keeps rising. So after much investigation I think it may be that the filling loop may have a leak in it so even when shut off it keeps filling the system very slowly.

To test this, I shut off the water to the house and it appears it does not rise after this (left for 24h with no increase in pressure).


At the moment every other day I have to let a good amount of water out of a rad nipple to keep the boiler at a good pressure.


After a bit of googling, it seems most combi boilers have a detachable filling loop which you only use when topping up. Mine seems to have one permanently attached.

Does anyone have any tips about replacing the filling loop? It looks like its a bugger to get to where it connect at the back of boiler With something like this http://www.NoLinkingToThis/p/combi-straight-filling-loop/46605



Or would it be easier just to replace this bit http://www.NoLinkingToThis/p/isolating-valve-with-handle-15mm/89226 and leave the end connected to the Boiler?

I'm guessing I would obviously have to drain down system first (or at least to below boiler level?).

I'm assuming its similar to replacing a tap? Please say if it's something you would not recommend a novice doing.

 

[Riley]

Might be helpful to post a picture of how your current filling loop is installed and we can offer some pearls of wisdom

 

[Alex Boothby]

Might be helpful to post a picture of how your current filling loop is installed and we can offer some pearls of wisdom

Sorry, I tried originally, but was having some problems doing so with Firefox for some reason.

Here you go. Thanks

 

[Riley]

Right well simple test would be to disconnect one end of the hose and see if any water is getting through

 

[Last Plumber]

If it's not that it could be a boiler fault You'd need a GSR engineer for that.

 

[Alex Boothby]

Right well simple test would be to disconnect one end of the hose and see if any water is getting through

Cheers, If I do that, would the water already inside the boiler spurt out at the pressure of the system? Would it be safer to bleed the system down first? And just replace the iso valve?

So, would I....

1. Shut water off
2. attach hose to rad and empty and open nipple.
3. remove filling loop from iso valve
4. fit new iso valve
5 close nipples
6. re fill/pressurise system and keep an eye on the pressure for next day?


Thank again

 

[joni os]

Once pressure in boiler is zero, close bleed nipples etc, minimal water will escape from your boiler, provided only one open end and air cannot enter system. No need to drain down.

 

[JCplumb]

Could be worth taking the screw out of the ISO handle to check it is turning all the way off, those plastic handles can lie to you about what position the valve is really in.

 

[Alex Boothby]

Once pressure in boiler is zero, close bleed nipples etc, minimal water will escape from your boiler, provided only one open end and air cannot enter system. No need to drain down.

Beg your pardon for me being a bit thick....

But how do get the pressure to zero without draining down? Do you mean all I have to do is remove as much water out of a nipple until boiler reads zero?

At this point, I will turn the water off and replace the iso valve shown in pic?