I have an old Potterton PUMA 80e combi boiler that's losing pressure fast.
Over the last year or two I've had to top up the pressure every couple of months. The last time I topped it up, I may have increased the pressure a little too much as it made some load clanking noises. However it did run.
Now it loses pressure and automatically switches off twice a day.

Where is this water going? How can I make sure it's the boiler at fault and not some leak elsewhere?

I'm trying to hold off just a few months more before replacing the boiler at the same time as a house extension.

Many thanks,
Sean

Sean, January 2005

could laying a new floor cause boiler pressure to drop ?

kirsty, March 2010

WATER LEAKING FOR THE PRESSURE RELEASE VALVE PIPE .ANY SOLUTIONS?

JAIME, March 2010

my boiler is the same was losing pressure so i had to top iot up once a month i am now doing it every morning. My dad use to fit boilers after having a chat with him i have found out mine is leaking but out through the back. the blow value in the back that realeases the pressure if over pressurived has gone adn the pipe that goes up the back of my house intot he boiler has a big puddle under it. so it looks like mine is the blow value. Start your boiler up once it is pressured correctly and go to that pip in your boiler where it comes out of the house once the system has been running for about 20 mins you will see it leaking if it is from there or you'll have a big pudle like i do. This doesn't mean you need a new boiler just means you need to replace the blow value maybe the spring in the boiler.

p tuthill, October 2007

Boiler dropping pressure means there is a leak, if you increase the pressure to much (2.5-3 bar) the pressure release valve should trip this is what it sounds like has happened. Check the pipe venting to the out side (from the pressure release valve) to see if there is water dripping from it, if so your release valve is not quite shut.
If it is not leaking along the pipe then you must have a leak somewhere else
(Pressure release valve should be under the boiler with red knob some times little spring lever)

bid, January 2005