Combination boilers and unvented system boilers need to have about 1 to 2 bar of pressure for the boiler to work, if is is not there then the boiler fail safe may shut down the boiler.

If you have to keep re-pressurising the system then there are a number of possible problems, a leak in pipework, the expansion vessel is leaking air, the expansion vessel needs replacing or there is insufficient inhibitor in the system. These are the most common reasons. We can help to resolve this issue for you.