Oil Heatslave Pressure problem

13 May 2007
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United Kingdom
Just had my Heatslave 20/25 oil boiler serviced.

Everything is OK except the system pressure, starting off from cold at just below 1 Bar but when system (heating) is up to temp the pressure has risen to just below 3 Bar.

Checked the expansion tank and that seems fine with a pressure of 1 Bar and no water from the schrader valve.

One thing though is that the expansion tank pressure stays at 1 Bar even when the system pressure is up to 3 Bar.

I am wondering whether the pipe from the boiler to the expansion tank could be blocked.

Any suggestions guys (or gals).

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Hi, i take it when you have checked the vessell pressure there was no system pressure and the prv was open?? also check the braided line to the vessell is not kinked.
Pressure was checked when I drained some of the system to give me no pressure on the boiler gauge.

With 0 pressure on the boiler gauge, the vessel pressure shows just under 1 bar.
With 3 bar (or near enough) on the boiler gauge, the pressure vessel still shows just under 1 bar.

That is what makes me suspect the flexible between the vessel and the boiler.
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