Baxi 80e Boiler pressure problem

9 Oct 2007
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United Kingdom
Hi There,
I have a Baxi 80e Boiler, over the last 3-4 weeks I have a problem which is becoming more frequent.
When I get up on a morning the heating has not come on with the timer, a look at the boiler gives a fault light of 'Low Pressure'.
The pressure gauge shows around 2.25 bar pressure, I then top up the pressure from the valve under the boiler with mains water until the pressure gauge shows 3 to 3.5 bar.
The Boiler will now function correctly, however I have noticed that the overflow is then slowly 'dripping' which i assume is overpressure. The pressure over the course of the next 24 hours seems to stabilise back at about 2.25 bar, at which point I get the fault light back.
HISTORY: I have had this boiler for about 4 years now, I have had to change the PCB 3 times already, The working pressure has always been around the 2-2.5 bar range and I have only had this problem before when the pressure once got down to about 1 bar. The pressure seems to stabilise at 2-2.5 bar and stay there so i'm sure i don't have a leak anywhere.

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It sounds as if the low pressure switch is out of calibration.

Would the pressure switch calibration have changed over the short period?

How do i fix it or calibrate it?

Thanks for the fast response.

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This is far more likely to be a pump fault and a dirty system.

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