Boiler losing pressure (slowly). Normal?

[CluelessDIYer1]

We removed a small radiator in the living room & ended up bending one of the 10mm copper pipes so water came piddling everywhere. Plumber came out to fix & all was good. Pressure appeared to stay constant.

Came time to put the big radiator on in the living room & tightening one nut up i slightly bent the pipe. I say slightly, it was very slightly, but the pipe certainly 'gave' a little. Not as bad as the small radiator to cause water to gush though.

I felt & felt around the connection & wasn't sure if it was weeping or not so i tied a tissue around it.

After some weeks i noticed the pressure dropping so i'd have to re-pressure every so many weeks.

Another issue requiring another plumber visit (i know, stop trying to DIY & get a pro to do it) & the small rad was then put back on as part of his visit.

The pressure on the boiler has started dropping a little quicker now.

He came about 3 weeks ago & the boiler was left at 1.5bar. It's now dropped to about 1.2bar. Every time i pressure it it will drop after a few weeks.

I turned up the radiator TRV settings from 3 to just over 4 & turned the room setting up to get the radiators going ... this brought the pressure up to about 1.8 i think. Upper end of 1 for sure. This was yesterday.

Came back today & it's back down at 1.25 approx.


We don't live in the house at the moment so we've only got the room setting at 15c. No showers are being had etc. so i don't know if this is a factor.


I mentioned to the plumber i bent the pipe a little on the big rad & i'm not sure if it's weeping. He had a look & said it's fine, but then if the rad isn't on would it be weeping anyway if it was only a very slight leak?


Just wondering if all this is normal as it doesn't sound right to me.

 

[Newboy]

The pressure in the heating loop will vary dependant on the temperature.

When cold usually around 1 bar

When at operating temperature around 1.5 - 2.5 bar is normal.

If the pressure is dropping significantly then there are a number of possible reasons but you need to establish if it is dropping or you are reading the pressure when the system is hot/cold.

Don't top it up then you will have an idea of if it is actually dropping.

 

[CluelessDIYer1]

Encouraging news then. Thanks.

I top it up as it gets on the verge of going in to the red. The last time it did that it made all sorts of clanging noises which i'm sure can't be anything good. Although when it went in to the red, if i remember right it was after we'd drained a lot of water off & didn't know to repressure (d'oh).

What should i do then, just ride it out to see how low it drops? If so then what about when it's bordering red/green?

 

[Newboy]

When the system is cold, make a note of the pressure (or top it up to 1 bar). Wait to see if it drops and then come back here and let us know the time taken.