fluctuating pressure - confused????

[coldwrench]

Hi All,

I have had pressure loss in my sealed CH system for a while now.

I top up the system to 1 bar while the system is cold. The CH timer switches the system on in the morning and the pressure rises to 1.4 bar. The system switches off after 2 hours and the pressure drops. So that, when I take a reading at midday the pressure reads 0 bar. After that, the pressure starts to gradually rise again to 1 bar throughout the afternoon. Then, in the evening, the timer switches the heat on again and the pressure rises to 1.4 bar. This cycle continues on a daily basis.

With the large pressure drop I see between morning and midday, I was convinced I had a leak, but now I’m not sure. I searched everywhere that I could access to find a leak, but could not find any.

Can anybody offer any ideas as to why the pressure would fluctuate like this?

Boiler is a Vokera Mynute 20SE.

Thanks.

 

[Billy Bob Bob]

how often do you top up? it sounds like you are looking when the water has expanded

 

[Ockyvines]

Hi All,

I have had pressure loss in my sealed CH system for a while now.

I top up the system to 1 bar while the system is cold. The CH timer switches the system on in the morning and the pressure rises to 1.4 bar. The system switches off after 2 hours and the pressure drops. So that, when I take a reading at midday the pressure reads 0 bar. After that, the pressure starts to gradually rise again to 1 bar throughout the afternoon. Then, in the evening, the timer switches the heat on again and the pressure rises to 1.4 bar. This cycle continues on a daily basis.

With the large pressure drop I see between morning and midday, I was convinced I had a leak, but now I’m not sure. I searched everywhere that I could access to find a leak, but could not find any.

Can anybody offer any ideas as to why the pressure would fluctuate like this?

Boiler is a Vokera Mynute 20SE.

Thanks.

Is your filling loop connected all the time?
It could be letting by and gradually filling until the pressure relief valve cuts in and lets all the pressure out

 

[coldwrench]

how often do you top up? it sounds like you are looking when the water has expanded

I last topped up 1 week ago.

Is your filling loop connected all the time?
It could be letting by and gradually filling until the pressure relief valve cuts in and lets all the pressure out

As soon as I noticed that the pressure was "recovering" I disconnected the filling loop and monitored the pressure over the following few days. The fluctuation remained after disconnecting the filling loop.