Boiler pressure high since annual service

kuepper

My glow worm 30cxi boiler manual says pressure should be between 0.7-1.0 bar and in 3 years here it's always been within those parameters and not needed topping up. When I had my annual boiler service 2 weeks ago the engineer said it would be better topped up to 1.2 bar so he did. I don't look at the display all the time but tonight I noticed it was up to 1.6 bar before I put my heating on and it got up to 2.2 bar after about half an hour. Do you think this merits a call out or is it normal, I'm wondering if the engineer has done something to cause this?

mchale

Bleed a couple of rads, that will drop pressure down.

elliot341

Pressure goes up when the heating is on as the water expands, the internal expansion valve will release any extra pressure if required. If your pressure goes up over 3bar etc maybe then speak to the guy who serviced it.

Ectophile

Check that both taps at the ends of the filling loop are properly turned off. If they are not, some water may be leaking through and pressurising the system.

If you want to drop the pressure, just let a bit of water out through one of the radiator bleed valves.

Lgas

2.2 isn't much cause for concern, but if it's edging towards the 3 bar mark release some water and then monitor again, and as stated already, make sure that filling loop is fully turned off. 0.7 is the minimum pressure your boiler needs to operate, a lot of boilers (especially condensers) have a low water cutout device when the pressure drops below that.

kuepper

Thanks for reassuring replies. It's not increasing so seems to be at 1.5 or 1.6 when the boiler is off, should I just leave it at that or should I release water til it gets down to 1.0? I just wondered if it'll do any harm being at 1.5 which is 50% above manual recommendation

Lgas

No it's perfect where it is

ariba10

If you are worried about the pressure all you need do is (When the system is off and cold) drain a little water off via one of the bleed nipples.

Not a lot.

thor

Lgas wrote: »

2.2 isn't much cause for concern, but if it's edging towards the 3 bar mark release some water and then monitor again, and as stated already, make sure that filling loop is fully turned off. 0.7 is the minimum pressure your boiler needs to operate, a lot of boilers (especially condensers) have a low water cutout device when the pressure drops below that.

My boiler loses pressure going from 1.0 to 0 in a matter of months and because I'm too lazy to re-pressurise it, it oftens stays at zero for many months more. It has never once stopped working. I no longer worry about it running on zero pressure(although I have recently topped it up). I can't figure out why the low pressure appears to have no effect.

roddydogs

My MILs combi is 0.4 bar when warm, Im not getting involved as I dont want the hassle. Seems to work fine

Mr_Ted

Lgas wrote: »

No it's perfect where it is

:rotfl::rotfl:How can that be if the manufacturers literature, like most, says 1 bar :rotfl:

The higher the cold pressure the more expansion will take place which will raise the pressure, the more the pressure is raised the more likelihood of overpressure issues and the possibility of leaks and blown safety valves:p

Drop it to 1bar as is recommended