Acceptable pressure drop

[f49h]

Hi
I have just fitted new pipes for my central heating system (22mm supply & return, 15mm T to radiators)
I will be getting a combi boiler fitted and have tested the pipework from my mains this is 3.5 bar.
Over a period of 3 hours it droped approx 0.2 of a bar.
Is this acceptable or should there be no pressure drop.
Perhaps another visit under the floor is needed.
Thanks

 

[ChrisR]

In 3 hours, no drop at all!

 

[Agile]

If its all new rads and pipework then there is a possibility that the small drop is caused by chemical action, thermal effects and trapped air dissolving.

Monitor the pressure over a longer period such as 24 hours and see if it continues to drop.

Tony