*old* central heating system - no filling loop?

[techsnake]

Hi all,

Excuse my ignorance, I'm not a plumber, but going mad trying to work out what's going on with the pressure in the central heating system..

The pressure is less than 1 bar, and I can't find the filling loop anywhere! It's driving me crazy! I've been up in the loft to check to see if it can be topped up up there, and there's just an old water tank that has been dry for what looks like decades. No other water tanks in the loft.. There's an immersion heater in one of the upstairs bedrooms, but there are no clues in the pipe-work there for topping up the central heating system.

It's a combi-boiler that must be really old - A Worcester 24i. I've checked online to try and find a manual for it, but I'm out of luck - all of the manuals are for modern combi-boilers

Does anyone know if a filling loop was required 20-odd (or more) years ago? I've checked inside the boiler, opened it up, and there are 2 screw-type valvues. One's red, with 3-bar, which I guess is to release pressure if it's too high. The other one's blue, but when you twist it, it starts spitting out water!!

I'm really lost - I've had a look underneath the boiler and in a small cupboard where the cold-water feed comes from (wth a stop-cock) but still no obvious way to top it up!! Don't know what to do - is the boiler safe at a low pressure, or is it just inefficient??

Thanks everyone - if anyone can help it would be really appreciated..

 

[macplumb]

if you have no filling loop with this boiler then the chancers are that you will have a filling key. this will be on the back side of the bottom pannel.
this should slot in the bottom of the boiler next to where the mains enters.
hope this helps

 

[helpsy]

I think they come with a plastic key with 2 "O" rings on that you push up into tube and lock in place then turn little white plastic block to fill heating circuit, then shut off and remove plastic key. Usually attached to panel under boiler.

 

[migoplumber]

or check the floorboards under the boiler, my mother in laws' has just caused me the same headache !

 

[wnjswozo]

it will be external filling loop,you find may have be fitted in rigid pipe,have good look around boiler there will be one near,very unlikely to be away from boiler,as you need to see pressure rise as you fill it,to know when to stop

 

[GreenArmy]

The manual is here. Read page 7

 

[techsnake]

Thanks everyone for your help - really appreciate it.

There is a filling loop, it was hidden inside some wood panelling on the wall believe it or not! After getting the screwdriver out and following the pipes it revealed itself at last!

Thanks again, and the manual is really useful!

Cheers, Paul.