How to Repressurise Your Boiler

pressure gaugeOne of the most common calls we get from our Bristol plumbing customers is regarding low water pressure on the gauge on the front of their boiler. On some new boilers this will completely stop the boiler from working, often generating boiler error codes or fault lights or symbols appearing. It can be sometimes be accompanied by knocking in central heating pipes or from the boiler itself, or a hissing noise when the central heating is operated. If you need to top up the boiler pressure but don’t know how then read on…

Our first advice is always not to panic! This may not be anything to worry about, or indeed any reason to spend on a heating engineer callout. All sealed heating systems, including all combi boilers, need to be repressurised once in a while. Typically customers will need to refill their sealed systems three or four times per year due to small amounts of evaporation from auto air vent valves and compression fittings. Alternatively you may have lost all of your pressure when bleeding radiators, or your boiler could have a fault that is causing it to lose pressure in one way or another – if this is the case it will need to be investigated by a qualified & experienced heating engineer.

dripping fittingIf you are certain that your system needs to be refilled, the first step to take is to identify whether you have a filling loop / tap on your heating system pipework, or if your boiler has an integrated refill system such as the Worcester Greenstar Filling Link (instructions here) and the Vaillant Ecotec Plus.  Each system is expanded on in our next posts.