Combi Boiler Losing Pressure
Discussion
Hi all
My wife and I both work away quite often. We turn the heating off whilst away (using Heat Genius, but don't think it matters).
Over the last few months, after the heating has been off for a few days and no hot water demand, the boiler loses pressure and gets E119 error code. It's a Baxi or Potterton (I'll check later). Opening the taps to top off the water supply fixes the issue.
Another strange one is that when the heating is on, the shower (about 1m from the boiler) is usually cold. When the heating is off, the shower is fine.
Any ideas?
Thanks in advance!
My wife and I both work away quite often. We turn the heating off whilst away (using Heat Genius, but don't think it matters).
Over the last few months, after the heating has been off for a few days and no hot water demand, the boiler loses pressure and gets E119 error code. It's a Baxi or Potterton (I'll check later). Opening the taps to top off the water supply fixes the issue.
Another strange one is that when the heating is on, the shower (about 1m from the boiler) is usually cold. When the heating is off, the shower is fine.
Any ideas?
Thanks in advance!
First thing to do is fire up the heating and watch the pressure gauge. If it starts creeping up to 3 bar, you have an issue with the expansion vessel.
At 3 bar, the pressure relief valve will open and let excess pressure pass to outside, which results in low system pressure when the boiler cools down.
The vessel could either just need recharging or more likely need replacing.
At 3 bar, the pressure relief valve will open and let excess pressure pass to outside, which results in low system pressure when the boiler cools down.
The vessel could either just need recharging or more likely need replacing.
KTF said:
A combi cant do heating and hot water at the same time hence when the heating is on the shower water is cold and vice versa.
Combis are priority hot water, so running a hot tap would override the heating function.Depending what setup it uses, it could be a diverted valve/flow switch fault. These faults usually show up first on showers as they don't draw as much hot water as other taps, so the boiler doesn't detect the demand for hot water.
Try running another hot tap at the same time and see if it makes a difference.
It seems I have an issue with this just recently.
Once in a while, maybe 2-3 times a year I need to give me boiler a helping hand and open the fill tap to restore pressure to a working range because it drops. This is, I understand fairly normal for a combi - its not overpressurising and dumping (I have a bucket under the outlet, it stays dry), pressure it just lost somewhere.
Over the past week or two I've had to do this a few times. I presume there is some sort of regulator that opens to replace used hot water - is it possible this is going faulty and not filling when it should ? any easy way to test ?
Could there be another reason ?
Other than this, the boiler works fine. I can never remember what its called, but its a double barreled french sounding name. About 12-13 years old. Its a Chaffoteaux britony, I believe they are part of the Ariston group.
Once in a while, maybe 2-3 times a year I need to give me boiler a helping hand and open the fill tap to restore pressure to a working range because it drops. This is, I understand fairly normal for a combi - its not overpressurising and dumping (I have a bucket under the outlet, it stays dry), pressure it just lost somewhere.
Over the past week or two I've had to do this a few times. I presume there is some sort of regulator that opens to replace used hot water - is it possible this is going faulty and not filling when it should ? any easy way to test ?
Could there be another reason ?
Other than this, the boiler works fine. I can never remember what its called, but its a double barreled french sounding name. About 12-13 years old. Its a Chaffoteaux britony, I believe they are part of the Ariston group.
It just sounds like a small leak from the system.
Check for furring or scale around joints, or a little bit of damp etc.
It only takes about a cup full of water to move the gauge from 0 to 2 psi.
It may be OK when its warm but when it cools a small leak will occur when it cools and
it will dry quickly so you will find it harder to trace.
Bleed the rads, if they need doing within a short time air is getting in, i.e. water out.
Check for furring or scale around joints, or a little bit of damp etc.
It only takes about a cup full of water to move the gauge from 0 to 2 psi.
It may be OK when its warm but when it cools a small leak will occur when it cools and
it will dry quickly so you will find it harder to trace.
Bleed the rads, if they need doing within a short time air is getting in, i.e. water out.
Our old boiler did this for a while, turned out to be a tiny leak from a radiator valve. All through the winter when the heating was on the leak was small enough that it evaporated away so no tell tale puddle. It was only when it was warm enough that the heating wasn't on that we found the damp patch.
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