Boiler pressure dropping daily!

[eggtastico]

Hi,
My boiler has started playing up & the pressure is dropping daily.
I have had to refill it twice in the last 2 days.

I have not had the heating on since about May, so only been using hot water.
(The CH control knob is set to off).

Any help where to start diagnosing the issue?
I got a sneaky feeling that it may be a radiator playing up & causing a leak, is there a way I can bypass the CH for a few days so I can check?

Anything else I can check?

 

[Terry7556]

There is a small pipe (15mm) going from the boiler to the outside wall and it should end in a hook or return pointing at the wall. Has this been dripping? Any water signs under the boiler?

 

[eggtastico]

thanks for the quick reply.
From what I can see, there is no water on the floor under the boiler.
The outside pipe is not leaking either.

could a radiator leak cause it, even if if the CH is off & not in use?

 

[Terry7556]

Yes quite easily ,any damp spots on carpets under rads, damp patches on ceilings?

 

[eggtastico]

Yes quite easily ,any damp spots on carpets under rads, damp patches on ceilings?

Ive got 2 damp spots in the kitchen, but they have been there a while.
To me they look to be getting bigger - but also the plaster has blown on that wall (outside wall) and thought it was caused by that (saving to get that fixed!). Now I am thinking its the radiator/boiler causing it. Just the strange thing is the pressure has only dropped the last 2 days.
The rad is somewhere above it - I think I need to measure the size of the rad & the gap between the damp spots.
Ive always thought the rad was ill fitted. Ideally, I would like to bypass the CH system to see if the boiler holds the pressure as well - to isolate the problem is with the CH run somewhere.

 

[eggtastico]

pressure back to zero this morning.
Any idea how I can isolate the CH?

 

[eggtastico]

Ok,
I have found the culprit.
Living room radiator had a puddle under it.
Probably banged it on Saturday moving the furniture.

I have closed the thermostat for now and the leak has stopped. Just need to see if the pressure drops more. Im hoping I have not damaged the pipework that goes inside the wall cavity.