Boiler pressure dropping slowly HELP

[Deano3]

Hi all my boiler pressure is dropping slowly i topped it up 24/6/11 to 1.3 bar and its now just about 1 bar so its dropped .3 bar in a month is this normal and would it be a large or very small leak ? something to worry about ? also when heating is on it goes up then when it settles it goes back to the figures i provided its a combi boiler

any help would be great thanks.
Dean

 

[linkyplumb]

The pressure going up when the heating is on is normal, as long as it is not going up too quickly. That is the expansion vessel doing its job.

Check all rad valves, visible joints and pipework. As you say it is a very small leak, but irksome none the less.

What boiler is it?

Graham

 

[Deano3]

thanks mate its a british gas worchester c1, also another quick question mate i am fitting a outside tap soon and there is a 22mm pipe that goes from celing to floor in the boiler room and thats were the loop to top the boiler up comes off it goes into the boiler at one side and the 15mm loop goes in another side of the boiler would it be ok to take a 22mm reduced to a 15mm compression fitting and use 15mm pipe to run outside to tap ? would it not effect boiler in anyway and would it be good enough pressure to use a pressure washer etc ?

Thanks Dean