Combi boiler: water pressure question.

[bri160356]

My son recently moved house and the CH boiler is an 'Ideal Logic Combi ES30';...it’s about 2 or3 years old.

When the system is cold the water pressure shows approx 1.9Bar,...when the CH has been on for a while and everything is fully heated up the pressure gauge shows approx 2.9Bar.

If the boiler is then turned off the pressure returns to 1.9Bar within 15mins or so.

I took this picture about 5mins after the boiler was switched off;...about 2.4Bar.

https://i.postimg.cc/mkZ9JbT4/Loz-combi-pressure.jpg

Is this pressure range normal?

As ever, all advice gratefully received.

edit: sorry, forgot to add: the heating and hot water appears to be functioning perfectly.

 

[ianmcd]

No you have an expansion problem, probably just the expansion vessel needing recharged, look in the FAQs on here but the most important part is you MUST leave a drain point open while doing it

 

[bri160356]

No you have an expansion problem, probably just the expansion vessel needing recharged, look in the FAQs on here but the most important part is you MUST leave a drain point open while doing it

Many thanks for the reply.

Would you expect a lack of expansion tank pressure or other expansion tank problems to bring up an error code on the boiler display?

 

[bri160356]

Sorry, duplicate reply.

 

[ianmcd]

Many thanks for the reply.

Would you expect a lack of expansion tank pressure or other expansion tank problems to bring up an error code on the boiler display?

not on that boiler no but the boiler will be losing water through the pressure relief and will require frequent topping up

 

[bri160356]

Update:

The boiler water pressure (in its cold state) was reduced to 1 bar. There was no problem with the pressure in the expansion vessel,...the EV pressure was 1 bar.

The CH temp selector was set to its max setting and the Combi switched on;...(it's a 10 rad system).

The water pressure climbed slowly as the boiler/water temp increased and eventually settled at about 1.6 bar when fully heated-up and the burner had clicked off.

When the burner was active the pressure climbed slightly to 1.7 bar but dropped back to 1.6 bar when the burner was inactive.

All now seems in order.