Hi all.
We have an ARISTON Combi A Series boiler in our loft. The last number of years we have had a number of instances where it has either cut out for no apparent reason or lost pressure.
The cut outs are very infrequent and so are not at this time a concern. The pressure loss however is.
To cut a very long history short, it has had two new Pressure Relief Valves. The first time it seemed to remedy the pressure loss for a short time, about six months. After the second replacement it only lasted about a week, before losing pressure again.
Ever since the first occurrence of the pressure loss, I had noticed the ‘tell tail’ sign of a leak the appeared to originate from a sensor above the pressure relief valve. There was a line of white residue running down from the base of this sensor continuing down the PRV housing. But, because there was never any trace of water on the tray below, I assumed that this was a previous leak that had now been rectified.
Anyway, I asked the fitter to take a look at it and it was decided that this sensor could be the cause of the pressure loss. When the sensor was removed it was discovered that the ‘o ring’ seal was, well I can’t actually remember what was wrong with it, but I do remember it was worse for wear. We didn’t have a replacement sensor or ‘o’ ring and so some kind of temporary measure was agreed.
I should probably add at this point that during every partial drain down to replace each of the PRVs the expansion vessel was checked and the fitter was fairly confident (Not 100% though) that the expansion vessel was ok. There has never been any water on the top of the valve and no water has discharged when deflated, releasing the pressure.
Anyway, after doing the temp repair to the sensors ‘o ring’, we fired up the heating and all appeared well. The boiler has held pressure ever since, all the way through the summer, never loosing any pressure. Until now! Today, I went into the loft to see how the pressure was, predominately because there have been a few occasions during September of this year (2014) that we have switched on the heating to get some washing dry. It has lost pressure again! No sign of leaks on the tray and I have not noticed any signs of wet on the floor beneath the PRV discharge pipe.
So, other than the sensor ‘o ring’ temp repair I am non the wiser. Obviously I am not a Gas Safe fitter, or plumber.
WHY HAS THE BOILER NOT LOSSED PRESSURE THROUGH THE ENTIRE SUMMER?
Even when there has been countless occurrences where the boiler has been called on to generate hot water. i.e baths, showers, dishes.
I’ve been in the loft many times during the summer and it has held constant at 1.5 bar.
IS THE WATER FEEDING THROUGH THE PRESSURE SENSOR HOT AND THEREFORE EVAPORATING INSTEAD OF DRIPPING ONTO THE TRAY BELOW?
IF THE SENSORS DODGY ‘O RING’ NEEDS REPLACING, WHICH I ADMIT IT PROBABLY DOES, WHY DID IT NOT LEAK DURING THE SUMMER MONTHS
COULD IT BE THAT THE RADIATORS OR PIPEWORK BE THE LEAKING AND CAUSING THE LOSS OF PRESSURE?
BUT IF SO, WHY DID THEY NOT SLOWLY LOOSE PRESSURE OVER THE SUMMER?
Can someone please take a little time to expain the answers to these questions and give some sensible advise? Winter is fast approaching!
Many Thanks for taking the time to read this very lengthy message.
We have an ARISTON Combi A Series boiler in our loft. The last number of years we have had a number of instances where it has either cut out for no apparent reason or lost pressure.
The cut outs are very infrequent and so are not at this time a concern. The pressure loss however is.
To cut a very long history short, it has had two new Pressure Relief Valves. The first time it seemed to remedy the pressure loss for a short time, about six months. After the second replacement it only lasted about a week, before losing pressure again.
Ever since the first occurrence of the pressure loss, I had noticed the ‘tell tail’ sign of a leak the appeared to originate from a sensor above the pressure relief valve. There was a line of white residue running down from the base of this sensor continuing down the PRV housing. But, because there was never any trace of water on the tray below, I assumed that this was a previous leak that had now been rectified.
Anyway, I asked the fitter to take a look at it and it was decided that this sensor could be the cause of the pressure loss. When the sensor was removed it was discovered that the ‘o ring’ seal was, well I can’t actually remember what was wrong with it, but I do remember it was worse for wear. We didn’t have a replacement sensor or ‘o’ ring and so some kind of temporary measure was agreed.
I should probably add at this point that during every partial drain down to replace each of the PRVs the expansion vessel was checked and the fitter was fairly confident (Not 100% though) that the expansion vessel was ok. There has never been any water on the top of the valve and no water has discharged when deflated, releasing the pressure.
Anyway, after doing the temp repair to the sensors ‘o ring’, we fired up the heating and all appeared well. The boiler has held pressure ever since, all the way through the summer, never loosing any pressure. Until now! Today, I went into the loft to see how the pressure was, predominately because there have been a few occasions during September of this year (2014) that we have switched on the heating to get some washing dry. It has lost pressure again! No sign of leaks on the tray and I have not noticed any signs of wet on the floor beneath the PRV discharge pipe.
So, other than the sensor ‘o ring’ temp repair I am non the wiser. Obviously I am not a Gas Safe fitter, or plumber.
WHY HAS THE BOILER NOT LOSSED PRESSURE THROUGH THE ENTIRE SUMMER?
Even when there has been countless occurrences where the boiler has been called on to generate hot water. i.e baths, showers, dishes.
I’ve been in the loft many times during the summer and it has held constant at 1.5 bar.
IS THE WATER FEEDING THROUGH THE PRESSURE SENSOR HOT AND THEREFORE EVAPORATING INSTEAD OF DRIPPING ONTO THE TRAY BELOW?
IF THE SENSORS DODGY ‘O RING’ NEEDS REPLACING, WHICH I ADMIT IT PROBABLY DOES, WHY DID IT NOT LEAK DURING THE SUMMER MONTHS
COULD IT BE THAT THE RADIATORS OR PIPEWORK BE THE LEAKING AND CAUSING THE LOSS OF PRESSURE?
BUT IF SO, WHY DID THEY NOT SLOWLY LOOSE PRESSURE OVER THE SUMMER?
Can someone please take a little time to expain the answers to these questions and give some sensible advise? Winter is fast approaching!
Many Thanks for taking the time to read this very lengthy message.
