Cool - great advice all, however can you reduce your level to 'numpty'???
When you say 'check radiator system is completely sealed', how do I do this?!
Then when you say check expansion tank and put a bicycle pump on it, how do I do this?!?!
Here you go.
“It's pretty simple on that beast if you have a footpump with a decent gauge.
Firstly turn the power off to the boiler.
Next attach a hose to a drain off somewhere on the heating system and open the valve, leave it open until the water stops coming out.....
Leave the drain off open and pop the front cover off the boiler. Now don't touch anything except for the red expansion vessel down the right hand side, looks kind of like a metal hot water bottle!!
You should see a schraeder valve on it - don't let the name panic you it looks just like the ones that you pump your car tyres up with
Pop the pump on and check/adjust the pressure until it's reading 0.8 bar (or around 12psi in old money), as you do this some water will come out of the hose that you left on the open drain point. It's supposed to do that!
Cover back on and drain point closed then refill the boiler to 1.2 bar.
Finally power back on and run it for 30 mins. If you're lucky it's all fixed, if your not the pressure relief valve will be dripping”
I had the same thing a while ago not the same boiler but the same symptoms, re pumping the expansion vessle sorted all my issues.
You have to open the drain on a radiator somewhere in the system as you pump it up as some water will need to come out.
We took the fill cap off a towell rad, mrs stood there with my wet n dry vac while i pumped up the expansion vessel and sucked up the water that came out, can do the same thing with a bucket if you dont have a wet n dry vac.
Saved a fortune on calling out a plumber, didnt touch the gas side, no restrictions on working on your own plumbing so didnt break any rules
