Valiant ecotech plus 618 boiler - cold pressure 0.9bar. hot water pressure 1.2 bar. Heating and hot water pressure 2.3 bar

[vinny2000]

Hi,
My boiler pressure has recently increased to 2.3 bar and i am sure it was well under 2 bar when heating and hot water is on.

The odd part is the pressure is around 1.2 bar when only hot water is on.

I don't know if this new pressure rise for heating and hot water is normal.

To me it seems pressure rise is due to something in the central heating system causing the pressure to go up from what ot was before about 1.8 bar to 2 bar when hot.
When the system is off and cold pressure is 0.9 bar.

I am worried about it the pressure increase. Is 2.3 bar normal?

Please let me know what the pressure increase is due to and should i worry about it.
Thank you
Vinny

 

[picasso]

The expansion vessel needs to be recharged, has the boiler been serviced lately ?

 

[CBW]

No it is not “normal” operating conditions, but normal for a deflated/failed expansion vessel, this will require a gas safe registered engineer.

 

[vinny2000]

Thank you team..
Is it expensive to get it pressured or replace the expansion tank?

 

[DP]

Thank you team..
Is it expensive to get it pressured or replace the expansion tank?

Will ask what has been asked already……….
Has the boiler been serviced lately
Suspect not as EV would have been attended to.
There are other components that a service asks to be checked and adjusted if OOA
Replace the EV if you want, knock your self out

 

[Johntheo5]

If the pressure remains at this, no problem until next service but inform the service person of above, this will help to ensure that they depressurize the system and check the pre charge pressure etc.
If the pressure continues to rise slowly, suggest reducing the cold fill pressure from 0.9bar to 0.75bar (via rad vent) but no further, this should knock 0.3/0.5bar off the hot pressure and might keep you going until the next due service.

 

[vinny2000]

Hi all,
Thank you for all the suggestions.
Waited for service.. had to vent of some pressure in the meantime.

The service guy fixed it by adding air to the expansion vessel. There was zero pressure before.

Boiler back to normal.

Thanks again all.
Great forum!!
Vinny

 

[Johntheo5]

Keep a eye on it as that air must have leaked out over time, a squirt of soapy water after recharging would have told if its the schrader valve.

 

[vinny2000]

Thanks for the handy tip.
Much appreciated Johntheo5.