testing pipework

[dotto]

Hi guys. I have fitted a towel rail and before the builders screw down plywood and lay out floor tiles i would like to test the c/h pipework for leaks as i have branched off in order to fit a towel rail. I have pressurized the system to 2.6 bars with cold water ( combi boiler) for 3 hours. You normally test to 1.5 working pressure for 1 hour but since the PRV opens at 3 bars i pressurized to 2.6 bars and no leaks. Do you normally run the central heating to see if there is any leaks with hot water or pressurizing the system with cold water is enough? The reason why i am asking is because the programmer is broken and the gas enginneer should come next week to replace it so i can not run c/h..... in the meantime the builders want to screw down the plywood to the joist so i was wondering if the above test is sufficient to tell me that there are going to be definitely no leaks or building regs say that i should test with hot water? Thank you for your time.

 

[Dan Robinson]

Things can hold when cold and pop when they get hot...Unlucky when they do though.

 

[Fluffster]

How did you tee off compression solder or push fit?

Pete

 

[dotto]

Hi guys thanks for the prompt reply. I teed off with solder ring fittings and i even added some more solder even though i know that is not necessary.

 

[xr4x4]

If youve had the system at 2.6 bar and it isn't leaking, you would have to be very unlucky if it leaks.....ESP a solder fitting.

 

[mcmoby69]

If youve had the system at 2.6 bar and it isn't leaking, you would have to be very unlucky if it leaks.....ESP a solder fitting.

unless the flux has plugged any holes...... then when the heating is switched on...........

it happens! trust me i know.

run it hot before the floor goes down.

 

[xr4x4]

So you reckon flux is going to block a hole at 2.6 bar?

 

[kevplumb]

yeah of course it will

 

[coliholic]

Out of interest how did you pressure test it to 2.6 bar?

 

[dotto]

When i refilled the system, instead of shutting off the loop valve when the pressure gauge read 1 bar, i left the valve open till the pressure gauge read 2.6 bars.

 

[Dan Robinson]

I have had joints leak after a cold pressure test passed OK.... usually a bad run of solder caused it and thankfully rare.

Still a pain though as you hsve tto drain down all over again.

 

[kevplumb]

1 link the clock out and run it hot
last fitting i tested cold was at 58 bar
no it aint a typo

 

[misterdubya]

You need to heat test. Only happened to me once when flux must have help the pressure. When pump and heat washed the flux away it leaked. Drain-down, re-make the joint but a PITA when your busy.

 

[dotto]

Thanks you all for your inputs. BTW i could i run the C/H if the programmer has been smashed up? What wire should i link to? I am afraid i do not recall the name of the programmer off the cuff. Any help hugely appreciated. Thanks again.

 

[flameport]

Thanks you all for your inputs. BTW i could i run the C/H if the programmer has been smashed up? What wire should i link to? I am afraid i do not recall the name of the programmer off the cuff.

Depends on the programmer, but on the backplate, linking live to CH On will usually operate the heating. It's often terminal 4 - but don't assume this.
Any thermostats need to be set to maximum.

The other way is to set any zone valves to manual and put a temporary link in the boiler terminal block (such as the one which is usually there when the boiler is new) so the whole lot heats up.
Obviously reading the boiler instructions to find the correct place for the link.