Loss of pressure

[pipeslice]

Hi folks can you help""""""

Recentley installed 6 rads 1 unvented cylinder and a pellet burner.
Pressure gauge reads 1 1/2 bar. It all runs great for about 4 hrs until low water pressure k noks it all off and filling and venting has to take place to resume working.All pipework and fittings can be seen and no loss of water is seen.

My question is i have a automatic air vent on the coil flow in the attic, if any unvented air gets up there and is expelled by the vent will this be enough of a loss to cut the safety controls. If so will this get worse and worse and eventually boil or flash the boiler water.
Should the vent be changed to a manual only to be used upon filling thus making it a completely sealed system

Many thanks

 

[Razor900]

You fitted a solid fuel appliance to an unvented cylinder, since when was that allowed?

 

[pipeslice]

Pellet burner
Classed as solid fuel,they can be installed as a open vented system or sealed (with link controls on the mother board) More safety controls than you can shake a stick at

 

[muggles]

You might be able to connect them to either an OV or sealed heating system, but I'm fairly certain you can't connect pellet burners, or any other type of solid fuel appliance, to an unvented hot water cylinder, MODUS certainly say you can't http://www.modus-uk.org/q-and-a.php

 

[pipeslice]

Ok Ok Guys,

Forget the solid fuel thing,

Heat source 1 boiler
Heat output 6 rads
Unvented cylinder
No leaks

1 AUTOMATIC AIR VALVE

If the system has just been filled , vented and lit, can the movement of air in the system ie removed from said valve have a direct influence on the system volume
Which will cause pressure loss

 

[muggles]

If the AAV's doing it's job and venting air then yes, the system pressure will go down. Have you checked to see if any of the safety controls are dumping? Or tried closing the AAV to see what effect that has? If the AAV is venting and causing pressure loss, closing it will prove this.

 

[pipeslice]

Cheers muggles

Closed the AAV darn it fantastic all day,how did i miss a faulty one.

Just for fun opened it and within 2 hrs the system pressure was adios