Loss of Pressure in Central Heating
If you are experiencing a loss of pressure in your central heating system and regularly having to "top-up" there are a number of potential causes. Even for an experienced and qualified Gas Safe engineer there may be an element of trial and error to get to the cause of the problem.
The most common problems are boiler related:
  • A leaking valve, particularly a Pressure Release Valve
    • When heated, the water in the central heating system will expand. The Pressure Release Valve stops the pressure building up too much but if it’s faulty it may allow water to escape through the overflow pipe.
  • A non-operational expansion vessel which can mean:
    • The membrane inside the vessel that separates air from water has perished
    • A loss of air pressure inside
    • A blockage in a pipe connected to the expansion vessel

 ASIDE: What is an expansion vessel?
Basically, it maintains an even pressure throughout the system when the water expands or contracts as it heats or cools.

Possibly the next most common cause would be a leaking radiator or valve on a radiator. These leaks can be almost microscopic so a large accumulation of water does not materialise. A good trick is to place tissue paper in places you suspect there may be a leak and then see if any water stains appear.

The most dreaded leak in a system, both by homeowners and heating engineers is perhaps a pipe leaking somewhere under the floor. If you are in anything otherthan a ground floor flat then your downstairs neighbours may notify you of the leak before you know of it yourself. However, given that these leaks are often very small it may take some time for water to be noticeable in the form of water stains on the ceiling of the flat below.

Often the only way to track down a leak in pipes hidden under the floor is to lift the floor coverings (Carpets, Laminate, Tiles etc.) and floor boards and inspect the pipes. Few plumbers or heating engineers, in our experience, really relish tackling this sort of task. This is partly because of the pressure they will feel to find the leak as the customer worries about escalating costs and partly the complications of lifting then replacing flooring.

A trawl of the internet will show some companies offering “Thermal Imaging” to find leaks. However we would suggest exercising caution particularly if companies offer “No Find, No Fee” read the small print before you sign anything.
The good news though is that, once found, leaks in pipes are pretty straight forward to fix.

A possible solution for a leak in pipes that an engineer may suggest before embarking on lifting floor boards is to put a leak sealer into the system. This is a liquid that “magically” seals a small pipe leak sometimes permanently, sometimes less permanently.

To arrange for a thoroughly vetted and continuously appraised heating engineer to repair central heating system that is losing pressure call HomeForce on 0131 315 0000, complete a Request-A-Visit form or email us on info@homeforcegroup.co.uk