dry pressure testing, tiny overnight leak (I think...)

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I decided to use a Rothenberger dry pressure tester to test as I went with my replacement installation of central heating (moving cylinder, valves, pump, filter, etc...) and everything has worked great so far. Only fault found previously was the nuts on the pump valve not nipped up enough.

It's progressed a little further now and I'm close to the point when I tie in to the existing flow/returns and rads. But last night I pressurised with around 10psi and after 1 hour it was rock solid at the same 10psi - great, I thought. I decided to leave it overnight and, yep, this morning it was back to zero

I'm left thinking there is a leak, well der!!, but when I was testing last night I used leak spray (i.e. same stuff used for gas) and nothing bubbled up, I checked every fitting, all motorised valve joints - everything. and I saw nothing.

I'm using JG endcaps to cap off the yet to be connected pipes, all of which are pushed on firmly.

Either I have a leak in the pipe work, or the pump (which is new) or the motorised valves, or it could be the hwc coil.

it's a gravity system so pressure wise I'm pushing it harder than it will be pushed, but the whole idea it to dry test it before I introduce the wet stuff!

Am I being too hard on the system? 10psi isn't that much and over one night - it shouldn't leak, or is there some gotcha with this dry testing lark that I don't know about yet?

I can redo check again tonight but in the past the leak spray has been really useful, just not this time unfortunately :(

anything else to try?
 
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Be aware pressure testing with air is DANGEROUS particularly at that high a pressure, in fact lethal big time!!

For example if your push fit end cap was to have come off it could be just as lethal as firing a gun - exactly the same way as an air gun works.

The reason being air is a compressible gas and as such stores considerable energy when compressed. Pressure testing should be done with waster.

Air testing at any sort of pressure would involve big Health & Safety implications such as correct warning signs, evacuated building etc.
 
yep, I've read about the risks before I began and it's only me allowed in the area. I'm a DIYer.

indeed, I thought dry pressure testing not allowed on building sites in the UK for the dangers you rightly mention? but I don't work on building sites so perhaps it is allowed if safety can be assured.

I'm testing with no more than 10psi, but even with that I understand the risk.
 
I began and it's only me allowed in the area. I'm a DIYer.

Think about it. A fitting blows off and injuries you. You are alone. Can you be certain that you can call for help and someone will hear you. ?

DIYers are not immune to injury or death.
 
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yep, I've read about the risks before I began and it's only me allowed in the area. I'm a DIYer.

indeed, I thought dry pressure testing not allowed on building sites in the UK for the dangers you rightly mention? but I don't work on building sites so perhaps it is allowed if safety can be assured.

I'm testing with no more than 10psi, but even with that I understand the risk.
That post beggars belief!!

''I know the risks but I am only a DIYer''!! What you are doing can be likened to playing a game with a with a ball made of explosive but if you are happy risking life and limb so be it.

''but I don't work on building sites so perhaps it is allowed if safety can be assured.'' No it would not be, safety CANNOT be assured. How you going to guarantee your push fit will not come off? They are not designed for the purpose you are using it.

You are charging it up to 10 bar, 150psi, and you need to be in the vicinity of the installation to be able to do that.
 
You are alone. Can you be certain that you can call for help and someone will hear you. ?

I've been alone doing much more dangerous stuff than that. Still here, which means I have to finish house build. Mrs says I can die then, and ONLY then.

In all seriousness, I'm doing this as safely as I can. nothing is ever perfectly safe, but precautions limit the danger and I'm limiting pressure and ensuring any end caps are far away and none are close to my face etc.


Anyway, back to this pesky leak. I think, and I don't want to admit this because others on here have very strong views about how "leaky" these mag filters are, it might be the TF1 leaking ever so slightly. I've tightened it up and will also isolate it and will try again.
 
yep, I've read about the risks before I began and it's only me allowed in the area. I'm a DIYer.

can be likened to playing a game with a with a ball made of explosive but if you are happy risking life and limb so be it.

''but I don't work on building sites so perhaps it is allowed if safety can be assured.'' No it would not be, safety CANNOT be assured. How you going to guarantee your push fit will not come off? They are not designed for the purpose you are using it.

You are charging it up to 10 bar, 150psi, and you need to be in the vicinity of the installation to be able to do that.


Seriously, like "a ball made of explosive"?

And I'm testing to 10psi - who mentioned 150psi or 10 bar?
 
Why not just fill with water and test ? That way you will see the leak, its safe and it won't do loads of damage because there's not a lot of water in there.
 
It's the TF1

Sure someone told me these things leak....who was that? (Dan)

:cry:

It could, although this surely cannot be true, be my fitting of the TF1 :whistle:
 
yep, I've read about the risks before I began and it's only me allowed in the area. I'm a DIYer.

can be likened to playing a game with a with a ball made of explosive but if you are happy risking life and limb so be it.

''but I don't work on building sites so perhaps it is allowed if safety can be assured.'' No it would not be, safety CANNOT be assured. How you going to guarantee your push fit will not come off? They are not designed for the purpose you are using it.

You are charging it up to 10 bar, 150psi, and you need to be in the vicinity of the installation to be able to do that.


Seriously, like "a ball made of explosive"?

And I'm testing to 10psi - who mentioned 150psi or 10 bar?
Ok admit I misread post but even 10psi system will contain a lot of air under pressure and testing with leak spray, a virtual lubricant, will certainly still be dangerous.
 

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