can you use hot water when the rads are emptey on a combi bo

[robbus]

i would like to plum an aga into my heating system & was told i couldent leave the system connected to my worcester 240, even thouge we only use it for hot water. when i draned the rad's and used the hot suppley it was fine for 3 min then started bounsing and triped the reset. has anyone got any iders on whether i should be able to plum the aga into system and leve it conected to boiler(i know i will have to put an open tank feed in) or wether i can run the boiler with no water on the rad side. or any other iders welcome. cheers

 

[Fluffster]

Your combi needs to have at least 1/2 bar pressure in the heating circuit for it to operate on hw or ch mode.
An open vent system cannot provide such pressure.

There are ways in which you can presurise the system to enable the hw to operate and then link the heating circuit up to a seperate heat source ie your Aga.

Pete

 

[robbus]

cheers for that, could i cut the flow and return and link them together, with a filling loop valve in the middle, then re pressurize the system?

 

[Bahco]

Can you pipe up one rad to it temporarily so that there is some flow to assist the dissipation of heat .

 

[robbus]

the idea is that the boiler wont be used at all for ch, only being used for hot water. i wont to by pass boiler and connect all the rads to an aga, but still use the boiler for hot water, apparently the ch side of boiler needs a min of half bar pressure in, pressumerbley to keep the cross over valve working properly?