Sorry silly question on bleeding?
- Thread starter hoopyman
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Turn off boiler/pump. Doesn't really matter if TRV/handwheel valve is open or not since the valve on the other end will be open.
On an open vented/semi sealed system check the feed and expansion tank (normally in the roof) before bleeding - as it is possible to draw in muck and debris into the system.
On sealed systems eg most combis, system boilers the expansion vessel should be checked since bleeding the air out of the radiators can cause unforeseen problems.
On an open vented/semi sealed system check the feed and expansion tank (normally in the roof) before bleeding - as it is possible to draw in muck and debris into the system.
On sealed systems eg most combis, system boilers the expansion vessel should be checked since bleeding the air out of the radiators can cause unforeseen problems.
The expansion vessel accomodates the extra volume of water created as the heating system heats up. the vessel is presurised with air. Over time the air pressure within the vessel depletes (and cannot therfore accept the expanded water).
Often air trapped in the top of radiators serves a similar purpose. If the expansion vessel has not been checked for a number of years and you bleed the radiators then re-presurise the system with the filling loop you may find the pressure gauge needle rises to more than 2 Bar with the heating at full temperature. At around 3 bar the safety valve will open causing problems.
The expansion vessel air pressure should therfore be checked. This is a straightforward procedure depending on your competence and the boiler make/model.
Often air trapped in the top of radiators serves a similar purpose. If the expansion vessel has not been checked for a number of years and you bleed the radiators then re-presurise the system with the filling loop you may find the pressure gauge needle rises to more than 2 Bar with the heating at full temperature. At around 3 bar the safety valve will open causing problems.
The expansion vessel air pressure should therfore be checked. This is a straightforward procedure depending on your competence and the boiler make/model.
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Hi sorry for the delay its a vokera linear 28 combi boiler and its about two years old the only prob I'm having with the filling loop is that it keeps dropping to one bar Is I tried to fill it to 1.5 but it just keeps dropping to 1??? why do you think this is?
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